#!/usr/bin/env python3
"""Generate TypeScript benchmark fixture (~5-7K LOC)."""

import os, textwrap

BASE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "webapp_ts")


def w(path, content):
    full = os.path.join(BASE, path)
    os.makedirs(os.path.dirname(full), exist_ok=True)
    with open(full, "w") as f:
        f.write(textwrap.dedent(content).lstrip())


# ─── src/utils/helpers.ts ───
w(
    "src/utils/helpers.ts",
    """\
/** Shared utility helpers. */

/** Simple logger interface. */
export interface Logger {
    info(msg: string): void;
    error(msg: string): void;
    warn(msg: string): void;
}

/** Get a named logger instance. */
export function getLogger(name: string): Logger {
    return {
        info: (msg: string) => console.log(`[${name}] INFO: ${msg}`),
        error: (msg: string) => console.error(`[${name}] ERROR: ${msg}`),
        warn: (msg: string) => console.warn(`[${name}] WARN: ${msg}`),
    };
}

/** Validate that a request object has required fields. */
export function validateRequest(request: Record<string, unknown>): boolean {
    if (!request || typeof request !== "object") {
        throw new Error("Request must be an object");
    }
    const required = ["method", "path"];
    for (const field of required) {
        if (!(field in request)) {
            throw new Error(`Missing required field: ${field}`);
        }
    }
    return true;
}

/** Generate a unique request identifier. */
export function generateRequestId(): string {
    const ts = Date.now();
    const rand = Math.random().toString(36).substring(2, 8);
    return `req-${ts}-${rand}`;
}

/** Sanitize user input by removing control characters. */
export function sanitizeInput(value: string): string {
    if (!value) return "";
    return value.replace(/[\\x00-\\x1f]/g, "").trim();
}

/** Paginate a list of items. */
export function paginate<T>(items: T[], page: number = 1, perPage: number = 20): {
    items: T[];
    page: number;
    perPage: number;
    total: number;
    pages: number;
} {
    const total = items.length;
    const start = (page - 1) * perPage;
    const pageItems = items.slice(start, start + perPage);
    return {
        items: pageItems,
        page,
        perPage,
        total,
        pages: Math.ceil(total / perPage),
    };
}

/** Mask sensitive fields in an object for logging. */
export function maskSensitive(data: Record<string, unknown>, fields: string[]): Record<string, unknown> {
    const masked = { ...data };
    for (const field of fields) {
        if (field in masked) {
            const val = String(masked[field]);
            masked[field] = val.length > 4 ? val.slice(0, 2) + "***" + val.slice(-2) : "***";
        }
    }
    return masked;
}

/** Retry an async operation with exponential backoff. */
export async function retryOperation<T>(
    fn: () => Promise<T>,
    maxRetries: number = 3,
    delay: number = 1000
): Promise<T> {
    let lastError: Error | null = null;
    for (let attempt = 0; attempt < maxRetries; attempt++) {
        try {
            return await fn();
        } catch (e) {
            lastError = e as Error;
            await new Promise(resolve => setTimeout(resolve, delay * Math.pow(2, attempt)));
        }
    }
    throw lastError;
}
""",
)

# ─── src/errors.ts ───
w(
    "src/errors.ts",
    """\
/** Application error hierarchy. */

/** Base application error. */
export class AppError extends Error {
    public readonly code: number;

    constructor(message: string, code: number = 500) {
        super(message);
        this.name = "AppError";
        this.code = code;
    }

    /** Serialize to plain object. */
    toJSON(): Record<string, unknown> {
        return { error: this.name, message: this.message, code: this.code };
    }
}

/** Raised when input validation fails. */
export class ValidationError extends AppError {
    public readonly field: string | null;

    constructor(message: string, field: string | null = null) {
        super(message, 400);
        this.name = "ValidationError";
        this.field = field;
    }
}

/** Raised when a payment operation fails. */
export class PaymentError extends AppError {
    public readonly transactionId: string | null;

    constructor(message: string, transactionId: string | null = null) {
        super(message, 402);
        this.name = "PaymentError";
        this.transactionId = transactionId;
    }
}

/** Raised when a resource is not found. */
export class NotFoundError extends AppError {
    public readonly resource: string;
    public readonly identifier: string;

    constructor(resource: string, identifier: string) {
        super(`${resource} with id '${identifier}' not found`, 404);
        this.name = "NotFoundError";
        this.resource = resource;
        this.identifier = identifier;
    }
}

/** Raised when rate limit is exceeded. */
export class RateLimitError extends AppError {
    public readonly retryAfter: number;

    constructor(retryAfter: number = 60) {
        super(`Rate limit exceeded. Retry after ${retryAfter}s`, 429);
        this.name = "RateLimitError";
        this.retryAfter = retryAfter;
    }
}

/** Raised when authentication fails. */
export class AuthenticationError extends AppError {
    constructor(message: string = "Authentication required") {
        super(message, 401);
        this.name = "AuthenticationError";
    }
}

/** Raised when authorization fails. */
export class AuthorizationError extends AppError {
    constructor(action: string, resource: string) {
        super(`Not authorized to ${action} on ${resource}`, 403);
        this.name = "AuthorizationError";
    }
}

/** Raised when a database operation fails. */
export class DatabaseError extends AppError {
    public readonly query: string | null;

    constructor(message: string, query: string | null = null) {
        super(message, 500);
        this.name = "DatabaseError";
        this.query = query;
    }
}
""",
)

# ─── src/auth/tokens.ts ───
w(
    "src/auth/tokens.ts",
    """\
/** Token management: generation, validation, and lifecycle. */

import { getLogger } from '../utils/helpers';

const logger = getLogger("auth.tokens");

/** Token expiry in seconds. */
export const TOKEN_EXPIRY = 3600;

/** Refresh token expiry. */
export const REFRESH_TOKEN_EXPIRY = 86400 * 7;

/** Error thrown when token operations fail. */
export class TokenError extends Error {
    constructor(message: string) {
        super(message);
        this.name = "TokenError";
    }
}

/** Error for expired tokens. */
export class ExpiredTokenError extends TokenError {
    constructor() {
        super("Token has expired");
        this.name = "ExpiredTokenError";
    }
}

/** Error for invalid token scope. */
export class InvalidScopeError extends TokenError {
    constructor(scope: string) {
        super(`Invalid token scope: ${scope}`);
        this.name = "InvalidScopeError";
    }
}

/** Token claims interface. */
export interface TokenClaims {
    userId: string;
    email: string;
    role: string;
    exp: number;
}

/** Generate a new authentication token for a user. */
export function generateToken(user: { id: string; email: string; role: string }): string {
    logger.info(`Generating token for user ${user.id}`);
    const payload = {
        userId: user.id,
        email: user.email,
        role: user.role,
        exp: Date.now() + TOKEN_EXPIRY * 1000,
    };
    // Simulated token generation
    return Buffer.from(JSON.stringify(payload)).toString("base64");
}

/** Validate a token and return its claims. */
export function validateToken(token: string): TokenClaims {
    logger.info("Validating token");
    if (!token || token.length < 10) {
        throw new TokenError("Invalid token format");
    }
    try {
        const decoded = JSON.parse(Buffer.from(token, "base64").toString());
        if (decoded.exp && decoded.exp < Date.now()) {
            throw new ExpiredTokenError();
        }
        return decoded as TokenClaims;
    } catch (e) {
        if (e instanceof TokenError) throw e;
        throw new TokenError("Token decode failed");
    }
}

/** Refresh an existing token. */
export function refreshToken(oldToken: string): string {
    logger.info("Refreshing token");
    const claims = validateToken(oldToken);
    return generateToken({ id: claims.userId, email: claims.email, role: claims.role });
}

/** Revoke a single token. */
export function revokeToken(token: string): boolean {
    logger.info("Revoking token");
    // In real impl, would add to blacklist
    validateToken(token);
    return true;
}

/** Revoke all tokens for a user. */
export function revokeAllTokens(userId: string): number {
    logger.info(`Revoking all tokens for user ${userId}`);
    // In real impl, would invalidate all user sessions
    return 1;
}

/** Extract token from Authorization header. */
export function extractToken(request: { headers?: Record<string, string> }): string | null {
    const auth = request.headers?.["Authorization"] ?? "";
    if (auth.startsWith("Bearer ")) {
        return auth.substring(7);
    }
    return null;
}

/** Find a session by its token. */
export function findByToken(token: string): { userId: string; active: boolean } | null {
    logger.info("Looking up session by token");
    try {
        const claims = validateToken(token);
        return { userId: claims.userId, active: true };
    } catch {
        return null;
    }
}
""",
)

# ─── src/auth/service.ts ───
w(
    "src/auth/service.ts",
    """\
/** Authentication service with class hierarchy. */

import { getLogger } from '../utils/helpers';
import { validateToken, generateToken, TokenError } from './tokens';

const logger = getLogger("auth.service");

/** Base service providing shared functionality. */
export class BaseService {
    protected serviceName: string;
    protected initialized: boolean;

    constructor(serviceName: string = "base") {
        this.serviceName = serviceName;
        this.initialized = false;
    }

    /** Initialize the service. */
    initialize(): void {
        this.initialized = true;
        logger.info(`${this.serviceName} initialized`);
    }

    /** Shut down the service. */
    shutdown(): void {
        this.initialized = false;
        logger.info(`${this.serviceName} shut down`);
    }

    /** Check service health. */
    healthCheck(): { service: string; status: string } {
        return {
            service: this.serviceName,
            status: this.initialized ? "healthy" : "not_initialized",
        };
    }

    /** Ensure service is initialized. */
    protected requireInitialized(): void {
        if (!this.initialized) {
            throw new Error(`${this.serviceName} not initialized`);
        }
    }
}

/** User record interface. */
export interface User {
    id: string;
    email: string;
    name: string;
    role: string;
    passwordHash: string;
}

/** Authentication service handling login, logout, and user management. */
export class AuthService extends BaseService {
    private users: Map<string, User>;

    constructor() {
        super("auth");
        this.users = new Map();
    }

    /** Authenticate user and return token. */
    async login(email: string, password: string): Promise<string | null> {
        this.requireInitialized();
        logger.info(`Login attempt for ${email}`);
        const user = this._findUser(email);
        if (!user) {
            logger.warn(`User not found: ${email}`);
            return null;
        }
        // Verify password (simulated)
        if (user.passwordHash !== password) {
            return null;
        }
        const token = generateToken(user);
        logger.info(`Login successful for ${email}`);
        return token;
    }

    /** Log out a user by invalidating their token. */
    async logout(token: string): Promise<boolean> {
        this.requireInitialized();
        logger.info("Processing logout");
        try {
            validateToken(token);
            return true;
        } catch (e) {
            if (e instanceof TokenError) {
                logger.warn("Invalid token on logout");
            }
            return false;
        }
    }

    /** Get the current user from a token. */
    async getCurrentUser(token: string): Promise<User | null> {
        this.requireInitialized();
        try {
            const claims = validateToken(token);
            return this._findUser(claims.email) ?? null;
        } catch {
            return null;
        }
    }

    /** Change user password. */
    async changePassword(userId: string, oldPassword: string): Promise<boolean> {
        this.requireInitialized();
        logger.info(`Password change for ${userId}`);
        // Would verify old password and set new one
        return true;
    }

    /** Find a user by email. */
    _findUser(email: string): User | undefined {
        for (const user of this.users.values()) {
            if (user.email === email) {
                return user;
            }
        }
        return undefined;
    }
}

/** Admin service extending AuthService. */
export class AdminService extends AuthService {
    constructor() {
        super();
        this.serviceName = "admin";
    }

    /** Impersonate a user (admin only). */
    async impersonate(adminToken: string, targetUserId: string): Promise<string | null> {
        this.requireInitialized();
        const admin = await this.getCurrentUser(adminToken);
        if (!admin || admin.role !== "admin") {
            return null;
        }
        logger.info(`Admin impersonating user ${targetUserId}`);
        return generateToken({ id: targetUserId, email: "", role: "user" });
    }

    /** List all users (admin only). */
    async listAllUsers(adminToken: string): Promise<User[]> {
        this.requireInitialized();
        const admin = await this.getCurrentUser(adminToken);
        if (!admin || admin.role !== "admin") {
            return [];
        }
        return [];
    }
}
""",
)

# ─── src/auth/middleware.ts ───
w(
    "src/auth/middleware.ts",
    """\
/** Authentication middleware. */

import { getLogger, validateRequest } from '../utils/helpers';
import { validateToken, extractToken, TokenError } from './tokens';
import { AuthenticationError, AuthorizationError } from '../errors';

const logger = getLogger("auth.middleware");

const PUBLIC_PATHS = ["/health", "/login", "/register", "/docs"];

/** Verify authentication and attach user context. */
export function authRequired(request: Record<string, unknown>): Record<string, unknown> {
    validateRequest(request);
    const path = request["path"] as string;
    if (PUBLIC_PATHS.includes(path)) {
        return request;
    }
    const token = extractToken(request as { headers?: Record<string, string> });
    if (!token) {
        throw new AuthenticationError("Missing authentication token");
    }
    try {
        const claims = validateToken(token);
        return { ...request, user: claims, authenticated: true };
    } catch (e) {
        if (e instanceof TokenError) {
            logger.warn("Token validation failed in middleware");
        }
        throw new AuthenticationError("Invalid or expired token");
    }
}

/** Require a specific role. */
export function requireRole(request: Record<string, unknown>, requiredRole: string): void {
    const user = request["user"] as { role?: string } | undefined;
    const userRole = user?.role ?? "user";
    const hierarchy: Record<string, number> = { admin: 3, moderator: 2, user: 1 };
    if ((hierarchy[userRole] ?? 0) < (hierarchy[requiredRole] ?? 0)) {
        throw new AuthorizationError(requiredRole, request["path"] as string);
    }
}
""",
)

# ─── src/routes/auth.ts ───
w(
    "src/routes/auth.ts",
    """\
/** Authentication route handlers. */

import { getLogger, validateRequest, sanitizeInput } from '../utils/helpers';
import { AuthService } from '../auth/service';
import { validateToken, refreshToken, extractToken, TokenError } from '../auth/tokens';
import { authRequired } from '../auth/middleware';

const logger = getLogger("routes.auth");

/** Handle login requests. */
export async function loginRoute(request: Record<string, unknown>): Promise<Record<string, unknown>> {
    validateRequest(request);
    logger.info("Login route");
    const body = request["body"] as Record<string, string>;
    const email = sanitizeInput(body?.email ?? "");
    const password = body?.password ?? "";

    const service = new AuthService();
    service.initialize();
    const token = await service.login(email, password);

    if (token) {
        return { status: 200, data: { token, email } };
    }
    return { status: 401, error: "Invalid credentials" };
}

/** Handle logout requests. */
export async function logoutRoute(request: Record<string, unknown>): Promise<Record<string, unknown>> {
    const authed = authRequired(request);
    const token = extractToken(authed as { headers?: Record<string, string> });
    const service = new AuthService();
    service.initialize();
    if (token) {
        await service.logout(token);
    }
    return { status: 200, data: { message: "Logged out" } };
}

/** Handle token refresh. */
export async function refreshRoute(request: Record<string, unknown>): Promise<Record<string, unknown>> {
    validateRequest(request);
    const token = extractToken(request as { headers?: Record<string, string> });
    if (!token) {
        return { status: 401, error: "Missing token" };
    }
    try {
        const newToken = refreshToken(token);
        return { status: 200, data: { token: newToken } };
    } catch (e) {
        if (e instanceof TokenError) {
            return { status: 401, error: e.message };
        }
        throw e;
    }
}
""",
)

# ─── src/models/types.ts ───
w(
    "src/models/types.ts",
    """\
/** Shared type definitions. */

export enum UserRole {
    User = "user",
    Admin = "admin",
    Moderator = "moderator",
}

export enum PaymentStatus {
    Pending = "pending",
    Processing = "processing",
    Completed = "completed",
    Failed = "failed",
    Refunded = "refunded",
}

export enum EventType {
    UserRegistered = "user.registered",
    LoginSuccess = "auth.login_success",
    LoginFailed = "auth.login_failed",
    PaymentCompleted = "payment.completed",
    PaymentRefunded = "payment.refunded",
    PasswordChanged = "auth.password_changed",
}

export enum NotificationChannel {
    Email = "email",
    SMS = "sms",
    Push = "push",
    InApp = "in_app",
}
""",
)

# ─── src/models/user.ts ───
w(
    "src/models/user.ts",
    """\
/** User model. */
import { UserRole } from './types';
import { getLogger } from '../utils/helpers';

const logger = getLogger("models.user");

export interface UserRecord {
    id: string;
    email: string;
    name: string;
    role: UserRole;
    passwordHash: string;
    active: boolean;
    createdAt: number;
    deletedAt: number | null;
}

export class User {
    public readonly id: string;
    public email: string;
    public name: string;
    public role: UserRole;
    public passwordHash: string;
    public active: boolean;
    public createdAt: number;
    public deletedAt: number | null;

    constructor(data: UserRecord) {
        this.id = data.id;
        this.email = data.email;
        this.name = data.name;
        this.role = data.role;
        this.passwordHash = data.passwordHash;
        this.active = data.active;
        this.createdAt = data.createdAt;
        this.deletedAt = data.deletedAt;
    }

    isAdmin(): boolean {
        return this.role === UserRole.Admin;
    }

    softDelete(): void {
        this.deletedAt = Date.now();
        this.active = false;
        logger.info(`User ${this.id} soft-deleted`);
    }

    toJSON(): Record<string, unknown> {
        return {
            id: this.id,
            email: this.email,
            name: this.name,
            role: this.role,
            active: this.active,
            createdAt: this.createdAt,
        };
    }
}
""",
)

# ─── src/models/session.ts ───
w(
    "src/models/session.ts",
    """\
/** Session model. */
import { getLogger } from '../utils/helpers';

const logger = getLogger("models.session");

export interface SessionRecord {
    id: string;
    userId: string;
    tokenHash: string;
    ipAddress: string;
    createdAt: number;
    expiredAt: number | null;
}

export class Session {
    public readonly id: string;
    public readonly userId: string;
    public readonly tokenHash: string;
    public readonly ipAddress: string;
    public readonly createdAt: number;
    public expiredAt: number | null;

    constructor(data: SessionRecord) {
        this.id = data.id;
        this.userId = data.userId;
        this.tokenHash = data.tokenHash;
        this.ipAddress = data.ipAddress;
        this.createdAt = data.createdAt;
        this.expiredAt = data.expiredAt;
    }

    isActive(): boolean {
        return this.expiredAt === null;
    }

    expire(): void {
        this.expiredAt = Date.now();
        logger.info(`Session ${this.id} expired`);
    }

    static create(userId: string, tokenHash: string, ip: string): Session {
        return new Session({
            id: `sess-${Date.now()}`,
            userId,
            tokenHash,
            ipAddress: ip,
            createdAt: Date.now(),
            expiredAt: null,
        });
    }
}
""",
)

# ─── src/models/payment.ts ───
w(
    "src/models/payment.ts",
    """\
/** Payment model. */
import { PaymentStatus } from './types';
import { getLogger } from '../utils/helpers';

const logger = getLogger("models.payment");

export interface PaymentRecord {
    id: string;
    userId: string;
    amount: number;
    currency: string;
    transactionId: string;
    status: PaymentStatus;
    createdAt: number;
    completedAt: number | null;
}

export class Payment {
    public readonly id: string;
    public readonly userId: string;
    public readonly amount: number;
    public readonly currency: string;
    public readonly transactionId: string;
    public status: PaymentStatus;
    public readonly createdAt: number;
    public completedAt: number | null;

    constructor(data: PaymentRecord) {
        this.id = data.id;
        this.userId = data.userId;
        this.amount = data.amount;
        this.currency = data.currency;
        this.transactionId = data.transactionId;
        this.status = data.status;
        this.createdAt = data.createdAt;
        this.completedAt = data.completedAt;
    }

    complete(): void {
        this.status = PaymentStatus.Completed;
        this.completedAt = Date.now();
        logger.info(`Payment ${this.transactionId} completed`);
    }

    fail(reason: string): void {
        this.status = PaymentStatus.Failed;
        logger.info(`Payment ${this.transactionId} failed: ${reason}`);
    }

    refund(): void {
        this.status = PaymentStatus.Refunded;
        logger.info(`Payment ${this.transactionId} refunded`);
    }

    isCompleted(): boolean {
        return this.status === PaymentStatus.Completed;
    }

    toJSON(): Record<string, unknown> {
        return {
            id: this.id,
            userId: this.userId,
            amount: this.amount,
            currency: this.currency,
            transactionId: this.transactionId,
            status: this.status,
            createdAt: this.createdAt,
            completedAt: this.completedAt,
        };
    }
}
""",
)

# ─── src/database/pool.ts ───
w(
    "src/database/pool.ts",
    """\
/** Database connection pool. */
import { getLogger } from '../utils/helpers';
import { DatabaseError } from '../errors';

const logger = getLogger("database.pool");

export interface ConnectionHandle {
    id: string;
    createdAt: number;
    lastUsed: number;
    inUse: boolean;
    queryCount: number;
}

/** Manages a pool of database connections. */
export class ConnectionPool {
    private connections: ConnectionHandle[] = [];
    private poolSize: number;
    private initialized: boolean = false;

    constructor(private dsn: string, poolSize: number = 10) {
        this.poolSize = Math.min(poolSize, 50);
        logger.info(`Pool created: size=${this.poolSize}`);
    }

    /** Initialize the pool with connections. */
    initialize(): void {
        if (this.initialized) return;
        for (let i = 0; i < this.poolSize; i++) {
            this.connections.push({
                id: `conn-${i}`,
                createdAt: Date.now(),
                lastUsed: Date.now(),
                inUse: false,
                queryCount: 0,
            });
        }
        this.initialized = true;
        logger.info(`Pool initialized with ${this.poolSize} connections`);
    }

    /** Acquire a connection from the pool. */
    getConnection(): ConnectionHandle {
        if (!this.initialized) this.initialize();
        for (const conn of this.connections) {
            if (!conn.inUse) {
                conn.inUse = true;
                conn.lastUsed = Date.now();
                conn.queryCount++;
                logger.info(`Acquired connection ${conn.id}`);
                return conn;
            }
        }
        throw new DatabaseError("Connection pool exhausted");
    }

    /** Release a connection back to the pool. */
    releaseConnection(handle: ConnectionHandle): void {
        handle.inUse = false;
        handle.lastUsed = Date.now();
        logger.info(`Released connection ${handle.id}`);
    }

    /** Get pool statistics. */
    stats(): { total: number; active: number; idle: number } {
        const active = this.connections.filter(c => c.inUse).length;
        return { total: this.connections.length, active, idle: this.connections.length - active };
    }

    /** Shut down the pool. */
    shutdown(): void {
        this.connections = [];
        this.initialized = false;
        logger.info("Pool shut down");
    }
}
""",
)

# ─── src/database/connection.ts ───
w(
    "src/database/connection.ts",
    """\
/** Database connection and query execution. */
import { getLogger } from '../utils/helpers';
import { DatabaseError } from '../errors';
import { ConnectionPool, ConnectionHandle } from './pool';

const logger = getLogger("database.connection");

/** Query result wrapper. */
export interface QueryResult {
    rows: Record<string, unknown>[];
    affected: number;
    duration: number;
}

/** High-level database connection. */
export class DatabaseConnection {
    private pool: ConnectionPool;
    private transactionDepth: number = 0;
    private currentHandle: ConnectionHandle | null = null;

    constructor(pool: ConnectionPool) {
        this.pool = pool;
        logger.info("DatabaseConnection created");
    }

    /** Execute a SQL query. */
    async executeQuery(sql: string, params?: unknown[]): Promise<QueryResult> {
        const handle = this.acquire();
        const start = Date.now();
        try {
            logger.info(`Executing: ${sql.substring(0, 80)}...`);
            const rows: Record<string, unknown>[] = [];
            const duration = Date.now() - start;
            return { rows, affected: rows.length, duration };
        } catch (e) {
            throw new DatabaseError(String(e), sql);
        } finally {
            this.release(handle);
        }
    }

    /** Find a record by ID. */
    async findById(table: string, id: string): Promise<Record<string, unknown> | null> {
        const result = await this.executeQuery(`SELECT * FROM ${table} WHERE id = ?`, [id]);
        return result.rows[0] ?? null;
    }

    /** Find all records matching conditions. */
    async findAll(table: string, conditions?: Record<string, unknown>, limit: number = 100): Promise<Record<string, unknown>[]> {
        let sql = `SELECT * FROM ${table}`;
        if (conditions) {
            const clauses = Object.keys(conditions).map(k => `${k} = ?`);
            sql += ` WHERE ${clauses.join(" AND ")}`;
        }
        sql += ` LIMIT ${limit}`;
        const result = await this.executeQuery(sql, conditions ? Object.values(conditions) : []);
        return result.rows;
    }

    /** Insert a record. */
    async insert(table: string, data: Record<string, unknown>): Promise<string> {
        const cols = Object.keys(data).join(", ");
        const placeholders = Object.keys(data).map(() => "?").join(", ");
        await this.executeQuery(`INSERT INTO ${table} (${cols}) VALUES (${placeholders})`, Object.values(data));
        return String(data["id"] ?? "generated-id");
    }

    /** Update a record by ID. */
    async update(table: string, id: string, data: Record<string, unknown>): Promise<number> {
        const sets = Object.keys(data).map(k => `${k} = ?`).join(", ");
        const result = await this.executeQuery(`UPDATE ${table} SET ${sets} WHERE id = ?`, [...Object.values(data), id]);
        return result.affected;
    }

    /** Delete a record by ID. */
    async deleteRecord(table: string, id: string): Promise<boolean> {
        const result = await this.executeQuery(`DELETE FROM ${table} WHERE id = ?`, [id]);
        return result.affected > 0;
    }

    /** Begin a transaction. */
    beginTransaction(): void {
        this.transactionDepth++;
        if (this.transactionDepth === 1) {
            this.currentHandle = this.acquire();
            logger.info("Transaction started");
        }
    }

    /** Commit transaction. */
    commit(): void {
        if (this.transactionDepth > 0) {
            this.transactionDepth--;
            if (this.transactionDepth === 0 && this.currentHandle) {
                this.release(this.currentHandle);
                this.currentHandle = null;
                logger.info("Transaction committed");
            }
        }
    }

    /** Rollback transaction. */
    rollback(): void {
        this.transactionDepth = 0;
        if (this.currentHandle) {
            this.release(this.currentHandle);
            this.currentHandle = null;
            logger.info("Transaction rolled back");
        }
    }

    private acquire(): ConnectionHandle {
        if (this.currentHandle && this.transactionDepth > 0) return this.currentHandle;
        return this.pool.getConnection();
    }

    private release(handle: ConnectionHandle): void {
        if (this.transactionDepth === 0) {
            this.pool.releaseConnection(handle);
        }
    }
}
""",
)

# ─── src/database/queries.ts ───
w(
    "src/database/queries.ts",
    """\
/** Predefined query builders. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection, QueryResult } from './connection';

const logger = getLogger("database.queries");

/** User queries. */
export class UserQueries {
    constructor(private db: DatabaseConnection) {}

    async findByEmail(email: string): Promise<Record<string, unknown> | null> {
        logger.info(`Finding user by email: ${email}`);
        const result = await this.db.executeQuery("SELECT * FROM users WHERE email = ?", [email]);
        return result.rows[0] ?? null;
    }

    async findActiveUsers(limit: number = 100): Promise<Record<string, unknown>[]> {
        const result = await this.db.executeQuery("SELECT * FROM users WHERE active = 1 LIMIT ?", [limit]);
        return result.rows;
    }

    async searchUsers(query: string): Promise<QueryResult> {
        return this.db.executeQuery("SELECT * FROM users WHERE name LIKE ? OR email LIKE ?", [`%${query}%`, `%${query}%`]);
    }

    async softDelete(userId: string): Promise<boolean> {
        logger.info(`Soft-deleting user ${userId}`);
        const affected = await this.db.update("users", userId, { deletedAt: Date.now() });
        return affected > 0;
    }
}

/** Session queries. */
export class SessionQueries {
    constructor(private db: DatabaseConnection) {}

    async findActiveSession(token: string): Promise<Record<string, unknown> | null> {
        const result = await this.db.executeQuery("SELECT * FROM sessions WHERE token_hash = ?", [token]);
        return result.rows[0] ?? null;
    }

    async createSession(userId: string, tokenHash: string, ip: string): Promise<string> {
        logger.info(`Creating session for user ${userId}`);
        return this.db.insert("sessions", { userId, tokenHash, ipAddress: ip, createdAt: Date.now() });
    }

    async expireSession(sessionId: string): Promise<boolean> {
        const affected = await this.db.update("sessions", sessionId, { expiredAt: Date.now() });
        return affected > 0;
    }
}

/** Payment queries. */
export class PaymentQueries {
    constructor(private db: DatabaseConnection) {}

    async findByTransactionId(txnId: string): Promise<Record<string, unknown> | null> {
        const result = await this.db.executeQuery("SELECT * FROM payments WHERE transaction_id = ?", [txnId]);
        return result.rows[0] ?? null;
    }

    async findUserPayments(userId: string, status?: string): Promise<Record<string, unknown>[]> {
        logger.info(`Finding payments for user ${userId}`);
        if (status) {
            const result = await this.db.executeQuery("SELECT * FROM payments WHERE user_id = ? AND status = ?", [userId, status]);
            return result.rows;
        }
        const result = await this.db.executeQuery("SELECT * FROM payments WHERE user_id = ?", [userId]);
        return result.rows;
    }

    async createPayment(userId: string, amount: number, currency: string, txnId: string): Promise<string> {
        return this.db.insert("payments", { userId, amount, currency, transactionId: txnId, status: "pending", createdAt: Date.now() });
    }

    async updateStatus(txnId: string, status: string): Promise<boolean> {
        logger.info(`Updating payment ${txnId} to ${status}`);
        const result = await this.db.executeQuery("UPDATE payments SET status = ? WHERE transaction_id = ?", [status, txnId]);
        return result.affected > 0;
    }

    async calculateRevenue(startDate: string, endDate: string): Promise<number> {
        const result = await this.db.executeQuery(
            "SELECT SUM(amount) as total FROM payments WHERE status = 'completed' AND created_at BETWEEN ? AND ?",
            [startDate, endDate]
        );
        const row = result.rows[0];
        return row ? Number(row["total"] ?? 0) : 0;
    }
}
""",
)

# ─── src/database/migrations.ts ───
w(
    "src/database/migrations.ts",
    """\
/** Database migration management. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection } from './connection';
import { DatabaseError } from '../errors';

const logger = getLogger("database.migrations");

interface Migration {
    version: string;
    name: string;
    sql: string;
}

const MIGRATIONS: Migration[] = [
    { version: "001", name: "create_users", sql: "CREATE TABLE users (id TEXT PRIMARY KEY, email TEXT, name TEXT, role TEXT)" },
    { version: "002", name: "create_sessions", sql: "CREATE TABLE sessions (id TEXT PRIMARY KEY, userId TEXT, tokenHash TEXT)" },
    { version: "003", name: "create_payments", sql: "CREATE TABLE payments (id TEXT PRIMARY KEY, userId TEXT, amount REAL)" },
    { version: "004", name: "create_events", sql: "CREATE TABLE events (id TEXT PRIMARY KEY, type TEXT, payload TEXT)" },
    { version: "005", name: "create_notifications", sql: "CREATE TABLE notifications (id TEXT PRIMARY KEY, userId TEXT, channel TEXT)" },
];

/** Run pending migrations. */
export class MigrationRunner {
    constructor(private db: DatabaseConnection) {
        logger.info("MigrationRunner initialized");
    }

    async runPending(): Promise<number> {
        let count = 0;
        for (const migration of MIGRATIONS) {
            logger.info(`Applying migration ${migration.version}: ${migration.name}`);
            try {
                this.db.beginTransaction();
                await this.db.executeQuery(migration.sql);
                this.db.commit();
                count++;
            } catch (e) {
                this.db.rollback();
                throw new DatabaseError(`Migration ${migration.version} failed: ${e}`);
            }
        }
        logger.info(`${count} migrations applied`);
        return count;
    }

    async status(): Promise<{ applied: number; pending: number; total: number }> {
        return { applied: 0, pending: MIGRATIONS.length, total: MIGRATIONS.length };
    }
}
""",
)

# ─── src/services/base.ts ───
w(
    "src/services/base.ts",
    """\
/** Service base and hierarchy. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';

const logger = getLogger("services.base");

/** Service interface. */
export interface Service {
    initialize(): void;
    shutdown(): void;
    healthCheck(): Record<string, unknown>;
}

/** Auditable interface. */
export interface Auditable {
    recordAudit(action: string, actor: string, resource: string, details?: Record<string, unknown>): void;
    getAuditTrail(resource?: string, limit?: number): Record<string, unknown>[];
}

/** Re-exported BaseService for services layer. */
export { BaseService } from '../auth/service';
""",
)

# ─── src/services/cacheable.ts ───
w(
    "src/services/cacheable.ts",
    """\
/** Cacheable service with built-in caching. */
import { getLogger } from '../utils/helpers';
import { BaseService } from '../auth/service';

const logger = getLogger("services.cacheable");

/** Service with caching support. */
export class CacheableService extends BaseService {
    private cache: Map<string, { value: unknown; expiry: number }> = new Map();
    private defaultTtl: number = 300;

    constructor(serviceName: string = "cacheable") {
        super(serviceName);
    }

    /** Get value from cache. */
    cacheGet(key: string): unknown | null {
        const entry = this.cache.get(key);
        if (entry && Date.now() < entry.expiry) {
            logger.info(`Cache hit: ${key}`);
            return entry.value;
        }
        if (entry) this.cache.delete(key);
        logger.info(`Cache miss: ${key}`);
        return null;
    }

    /** Set value in cache. */
    cacheSet(key: string, value: unknown, ttl?: number): void {
        const effectiveTtl = ttl ?? this.defaultTtl;
        this.cache.set(key, { value, expiry: Date.now() + effectiveTtl * 1000 });
        logger.info(`Cache set: ${key} (ttl=${effectiveTtl}s)`);
    }

    /** Invalidate a cache entry. */
    cacheInvalidate(key: string): boolean {
        return this.cache.delete(key);
    }

    /** Clear all cache entries. */
    cacheClear(): number {
        const count = this.cache.size;
        this.cache.clear();
        logger.info(`Cache cleared: ${count} entries`);
        return count;
    }
}
""",
)

# ─── src/services/auditable.ts ───
w(
    "src/services/auditable.ts",
    """\
/** Auditable service with audit trail. */
import { getLogger } from '../utils/helpers';
import { BaseService } from '../auth/service';
import { Auditable } from './base';

const logger = getLogger("services.auditable");

interface AuditEntry {
    action: string;
    actor: string;
    resource: string;
    details: Record<string, unknown>;
    timestamp: number;
}

/** Service with audit logging. */
export class AuditableService extends BaseService implements Auditable {
    private auditLog: AuditEntry[] = [];

    constructor(serviceName: string = "auditable") {
        super(serviceName);
    }

    /** Record an audit entry. */
    recordAudit(action: string, actor: string, resource: string, details?: Record<string, unknown>): void {
        const entry: AuditEntry = {
            action, actor, resource,
            details: details ?? {},
            timestamp: Date.now(),
        };
        this.auditLog.push(entry);
        logger.info(`Audit: ${actor} ${action} on ${resource}`);
    }

    /** Query audit trail. */
    getAuditTrail(resource?: string, limit: number = 50): Record<string, unknown>[] {
        let entries = this.auditLog;
        if (resource) {
            entries = entries.filter(e => e.resource === resource);
        }
        return entries.slice(-limit).reverse();
    }
}
""",
)

# ─── src/services/authService.ts ───
w(
    "src/services/authService.ts",
    """\
/** High-level authentication service. */
import { getLogger, sanitizeInput } from '../utils/helpers';
import { AuthService } from '../auth/service';
import { validateToken, generateToken } from '../auth/tokens';
import { DatabaseConnection } from '../database/connection';
import { UserQueries, SessionQueries } from '../database/queries';
import { EventDispatcher } from '../events/dispatcher';
import { AuthenticationError, ValidationError } from '../errors';
import { BaseService } from '../auth/service';

const logger = getLogger("services.auth");

/** Orchestrates authentication flows. */
export class AuthenticationService extends BaseService {
    private auth: AuthService;
    private users: UserQueries;
    private sessions: SessionQueries;
    private events: EventDispatcher;

    constructor(db: DatabaseConnection, events: EventDispatcher) {
        super("authentication");
        this.auth = new AuthService();
        this.users = new UserQueries(db);
        this.sessions = new SessionQueries(db);
        this.events = events;
    }

    /** Authenticate a user — main entry point for login flow. */
    async authenticate(email: string, password: string, ip: string = "unknown"): Promise<Record<string, unknown>> {
        this.requireInitialized();
        logger.info(`Authentication attempt for ${email}`);
        const cleanEmail = sanitizeInput(email);
        if (!cleanEmail) {
            throw new ValidationError("Email is required", "email");
        }
        try {
            const token = await this.auth.login(cleanEmail, password);
            if (!token) {
                this.events.emit("auth.login_failed", { email: cleanEmail, ip });
                throw new AuthenticationError("Invalid credentials");
            }
            this.events.emit("auth.login_success", { email: cleanEmail, ip });
            return { token, email: cleanEmail };
        } catch (e) {
            if (e instanceof AuthenticationError) throw e;
            this.events.emit("auth.login_failed", { email: cleanEmail, ip });
            throw new AuthenticationError(`Authentication failed: ${e}`);
        }
    }

    /** Verify a token. */
    async verifyToken(token: string): Promise<Record<string, unknown> | null> {
        try {
            const claims = validateToken(token);
            return await this.users.findByEmail(claims.email);
        } catch {
            return null;
        }
    }

    /** Log out. */
    async logout(token: string): Promise<boolean> {
        logger.info("Processing logout");
        const session = await this.sessions.findActiveSession(token);
        if (session) {
            await this.sessions.expireSession(session["id"] as string);
            this.events.emit("auth.logout", { sessionId: session["id"] });
            return true;
        }
        return false;
    }
}
""",
)

# ─── src/services/payment/processor.ts ───
w(
    "src/services/payment/processor.ts",
    """\
/** Payment processor with diamond-like inheritance. */
import { getLogger, generateRequestId } from '../../utils/helpers';
import { CacheableService } from '../cacheable';
import { Auditable } from '../base';
import { DatabaseConnection } from '../../database/connection';
import { PaymentQueries } from '../../database/queries';
import { EventDispatcher } from '../../events/dispatcher';
import { PaymentError, ValidationError, NotFoundError } from '../../errors';

const logger = getLogger("services.payment");

const SUPPORTED_CURRENCIES = ["USD", "EUR", "GBP", "JPY", "CAD"];

/** Payment processor with caching + audit. */
export class PaymentProcessor extends CacheableService implements Auditable {
    private events: EventDispatcher;
    private queries: PaymentQueries;
    private auditLog: Array<{ action: string; actor: string; resource: string; details: Record<string, unknown>; timestamp: number }> = [];

    constructor(db: DatabaseConnection, events: EventDispatcher) {
        super("payment_processor");
        this.events = events;
        this.queries = new PaymentQueries(db);
    }

    /** Process a payment. */
    async processPayment(userId: string, amount: number, currency: string, method: string = "card"): Promise<Record<string, unknown>> {
        this.requireInitialized();
        logger.info(`Processing payment: user=${userId}, amount=${amount} ${currency}`);
        this.validatePayment(amount, currency);
        const txnId = generateRequestId();
        const cacheKey = `payment:${userId}:${amount}:${currency}`;
        if (this.cacheGet(cacheKey)) {
            throw new PaymentError("Duplicate payment", txnId);
        }
        try {
            await this.queries.createPayment(userId, amount, currency, txnId);
            await this.queries.updateStatus(txnId, "completed");
        } catch (e) {
            throw new PaymentError(`Payment failed: ${e}`, txnId);
        }
        this.cacheSet(cacheKey, txnId, 300);
        this.recordAudit("payment.processed", userId, `payment:${txnId}`, { amount, currency, method });
        this.events.emit("payment.completed", { transactionId: txnId, userId, amount, currency });
        return { transactionId: txnId, status: "completed", amount, currency };
    }

    /** Refund a payment. */
    async refund(transactionId: string, reason: string = ""): Promise<Record<string, unknown>> {
        logger.info(`Refunding: ${transactionId}`);
        const payment = await this.queries.findByTransactionId(transactionId);
        if (!payment) throw new NotFoundError("Payment", transactionId);
        await this.queries.updateStatus(transactionId, "refunded");
        this.recordAudit("payment.refunded", "system", `payment:${transactionId}`, { reason });
        this.events.emit("payment.refunded", { transactionId, reason });
        return { transactionId, status: "refunded" };
    }

    /** Record an audit entry. */
    recordAudit(action: string, actor: string, resource: string, details?: Record<string, unknown>): void {
        this.auditLog.push({ action, actor, resource, details: details ?? {}, timestamp: Date.now() });
        logger.info(`Audit: ${actor} ${action} on ${resource}`);
    }

    /** Get audit trail. */
    getAuditTrail(resource?: string, limit: number = 50): Record<string, unknown>[] {
        let entries = this.auditLog;
        if (resource) entries = entries.filter(e => e.resource === resource);
        return entries.slice(-limit);
    }

    private validatePayment(amount: number, currency: string): void {
        if (!SUPPORTED_CURRENCIES.includes(currency)) {
            throw new ValidationError(`Unsupported currency: ${currency}`, "currency");
        }
        if (amount <= 0) throw new ValidationError("Amount must be positive", "amount");
        if (amount > 999999) throw new ValidationError("Amount exceeds maximum", "amount");
    }
}
""",
)

# ─── src/services/payment/gateway.ts ───
w(
    "src/services/payment/gateway.ts",
    """\
/** Payment gateway abstraction. */
import { getLogger, generateRequestId } from '../../utils/helpers';

const logger = getLogger("services.payment.gateway");

interface GatewayResponse {
    success: boolean;
    txnId: string;
    message: string;
}

/** Payment gateway client. */
export class PaymentGateway {
    private requestCount: number = 0;

    constructor(private apiKey: string, private environment: string = "sandbox") {
        logger.info(`Gateway initialized: env=${environment}`);
    }

    /** Charge a payment source. */
    charge(amount: number, currency: string, source: string): GatewayResponse {
        logger.info(`Charging ${amount} ${currency}`);
        this.requestCount++;
        const txnId = generateRequestId();
        if (amount > 10000) return { success: false, txnId, message: "Exceeds limit" };
        return { success: true, txnId, message: "Charge successful" };
    }

    /** Refund a charge. */
    refundCharge(chargeId: string): GatewayResponse {
        logger.info(`Refunding charge ${chargeId}`);
        this.requestCount++;
        return { success: true, txnId: generateRequestId(), message: "Refund successful" };
    }

    /** Get request count. */
    stats(): { totalRequests: number } {
        return { totalRequests: this.requestCount };
    }
}
""",
)

# ─── src/services/notification/manager.ts ───
w(
    "src/services/notification/manager.ts",
    """\
/** Notification management. */
import { getLogger, sanitizeInput } from '../../utils/helpers';
import { BaseService } from '../../auth/service';
import { DatabaseConnection } from '../../database/connection';
import { ValidationError } from '../../errors';

const logger = getLogger("services.notification");

/** Notification object. */
interface Notification {
    userId: string;
    channel: string;
    subject: string;
    body: string;
    status: string;
    createdAt: number;
}

/** Manages notifications. */
export class NotificationManager extends BaseService {
    private queue: Notification[] = [];

    constructor(private db: DatabaseConnection) {
        super("notification_manager");
    }

    /** Send a notification. */
    async send(userId: string, channel: string, subject: string, body: string): Promise<Notification> {
        this.requireInitialized();
        logger.info(`Queuing notification for ${userId} via ${channel}`);
        const validChannels = ["email", "sms", "push", "in_app"];
        if (!validChannels.includes(channel)) {
            throw new ValidationError(`Invalid channel: ${channel}`, "channel");
        }
        const notification: Notification = {
            userId,
            channel,
            subject: sanitizeInput(subject),
            body: sanitizeInput(body),
            status: "pending",
            createdAt: Date.now(),
        };
        this.queue.push(notification);
        await this.db.insert("notifications", notification as unknown as Record<string, unknown>);
        return notification;
    }

    /** Process the notification queue. */
    async processQueue(): Promise<{ sent: number; failed: number }> {
        logger.info(`Processing ${this.queue.length} notifications`);
        let sent = 0;
        let failed = 0;
        for (const n of this.queue) {
            if (n.status === "pending") {
                try {
                    n.status = "sent";
                    sent++;
                } catch {
                    n.status = "failed";
                    failed++;
                }
            }
        }
        this.queue = this.queue.filter(n => n.status === "pending");
        return { sent, failed };
    }
}
""",
)

# ─── src/services/email/sender.ts ───
w(
    "src/services/email/sender.ts",
    """\
/** Email sending service. */
import { getLogger, sanitizeInput } from '../../utils/helpers';
import { CacheableService } from '../cacheable';
import { DatabaseConnection } from '../../database/connection';
import { ValidationError } from '../../errors';

const logger = getLogger("services.email");

const TEMPLATES: Record<string, string> = {
    welcome: "Welcome to our platform, {name}!",
    password_reset: "Reset your password: {link}",
    payment_receipt: "Payment of {amount} {currency} received. Txn: {txn_id}",
};

/** Email sender with templates. */
export class EmailSender extends CacheableService {
    private sentCount: number = 0;
    private failedCount: number = 0;

    constructor(private db: DatabaseConnection) {
        super("email_sender");
    }

    /** Send a single email. */
    async send(to: string, subject: string, body: string): Promise<boolean> {
        this.requireInitialized();
        logger.info(`Sending email to ${to}: ${subject}`);
        if (!to.includes("@")) throw new ValidationError("Invalid email", "to");
        try {
            await this.db.insert("notifications", { userId: "system", channel: "email", subject, body, status: "sent" });
            this.sentCount++;
            return true;
        } catch (e) {
            logger.error(`Email failed: ${e}`);
            this.failedCount++;
            return false;
        }
    }

    /** Send using a template. */
    async sendTemplate(to: string, templateName: string, context: Record<string, string>): Promise<boolean> {
        const template = TEMPLATES[templateName];
        if (!template) throw new ValidationError(`Unknown template: ${templateName}`, "template");
        let body = template;
        for (const [key, val] of Object.entries(context)) {
            body = body.replace(`{${key}}`, val);
        }
        const subject = `[App] ${templateName.replace("_", " ")}`;
        return this.send(to, subject, body);
    }

    /** Get sending stats. */
    stats(): { sent: number; failed: number } {
        return { sent: this.sentCount, failed: this.failedCount };
    }
}
""",
)

# ─── src/events/dispatcher.ts ───
w(
    "src/events/dispatcher.ts",
    """\
/** Event dispatcher. */
import { getLogger } from '../utils/helpers';

const logger = getLogger("events.dispatcher");

/** Event object. */
export interface AppEvent {
    type: string;
    data: Record<string, unknown>;
    timestamp: number;
    processed: boolean;
}

type EventHandler = (event: AppEvent) => void;

/** Central event bus. */
export class EventDispatcher {
    private handlers: Map<string, EventHandler[]> = new Map();
    private eventLog: AppEvent[] = [];

    /** Register a handler. */
    on(eventType: string, handler: EventHandler): void {
        if (!this.handlers.has(eventType)) this.handlers.set(eventType, []);
        this.handlers.get(eventType)!.push(handler);
        logger.info(`Handler registered for: ${eventType}`);
    }

    /** Emit an event. */
    emit(eventType: string, data?: Record<string, unknown>): number {
        const event: AppEvent = { type: eventType, data: data ?? {}, timestamp: Date.now(), processed: false };
        this.eventLog.push(event);
        const handlers = this.handlers.get(eventType) ?? [];
        logger.info(`Emitting ${eventType} to ${handlers.length} handlers`);
        let invoked = 0;
        for (const handler of handlers) {
            try {
                handler(event);
                invoked++;
            } catch (e) {
                logger.error(`Handler error for ${eventType}: ${e}`);
            }
        }
        event.processed = true;
        return invoked;
    }

    /** Get event count. */
    eventCount(): number {
        return this.eventLog.length;
    }
}
""",
)

# ─── src/events/handlers.ts ───
w(
    "src/events/handlers.ts",
    """\
/** Default event handlers. */
import { getLogger } from '../utils/helpers';
import { AppEvent, EventDispatcher } from './dispatcher';

const logger = getLogger("events.handlers");

export function onUserRegistered(event: AppEvent): void {
    logger.info(`User registered: ${event.data["email"]}`);
}

export function onLoginSuccess(event: AppEvent): void {
    logger.info(`Login success: ${event.data["email"]} from ${event.data["ip"]}`);
}

export function onLoginFailed(event: AppEvent): void {
    logger.info(`Login failed: ${event.data["email"]} from ${event.data["ip"]}`);
}

export function onPaymentCompleted(event: AppEvent): void {
    logger.info(`Payment completed: txn=${event.data["transactionId"]} amount=${event.data["amount"]}`);
}

export function onPaymentRefunded(event: AppEvent): void {
    logger.info(`Payment refunded: txn=${event.data["transactionId"]}`);
}

export function registerDefaultHandlers(dispatcher: EventDispatcher): void {
    dispatcher.on("auth.user_registered", onUserRegistered);
    dispatcher.on("auth.login_success", onLoginSuccess);
    dispatcher.on("auth.login_failed", onLoginFailed);
    dispatcher.on("payment.completed", onPaymentCompleted);
    dispatcher.on("payment.refunded", onPaymentRefunded);
    logger.info("Default handlers registered");
}
""",
)

# ─── src/cache/base.ts ───
w(
    "src/cache/base.ts",
    """\
/** Cache interface and base class. */

/** Cache interface. */
export interface CacheBackend {
    get(key: string): unknown | null;
    set(key: string, value: unknown, ttl?: number): void;
    delete(key: string): boolean;
    clear(): number;
}

/** Base cache with stats tracking. */
export abstract class BaseCache implements CacheBackend {
    protected name: string;
    protected hits: number = 0;
    protected misses: number = 0;

    constructor(name: string) {
        this.name = name;
    }

    abstract get(key: string): unknown | null;
    abstract set(key: string, value: unknown, ttl?: number): void;
    abstract delete(key: string): boolean;
    abstract clear(): number;

    stats(): { backend: string; hits: number; misses: number; hitRate: string } {
        const total = this.hits + this.misses;
        const rate = total > 0 ? (this.hits / total * 100) : 0;
        return { backend: this.name, hits: this.hits, misses: this.misses, hitRate: `${rate.toFixed(1)}%` };
    }
}
""",
)

# ─── src/cache/redisCache.ts ───
w(
    "src/cache/redisCache.ts",
    """\
/** Redis-backed cache. */
import { getLogger } from '../utils/helpers';
import { BaseCache } from './base';

const logger = getLogger("cache.redis");

/** Redis cache implementation. */
export class RedisCache extends BaseCache {
    private store: Map<string, unknown> = new Map();
    private expiry: Map<string, number> = new Map();

    constructor(host: string = "localhost", port: number = 6379) {
        super("redis");
        logger.info(`RedisCache created: ${host}:${port}`);
    }

    get(key: string): unknown | null {
        if (this.store.has(key)) {
            const exp = this.expiry.get(key) ?? Infinity;
            if (Date.now() > exp) {
                this.store.delete(key);
                this.expiry.delete(key);
                this.misses++;
                return null;
            }
            this.hits++;
            return this.store.get(key) ?? null;
        }
        this.misses++;
        return null;
    }

    set(key: string, value: unknown, ttl: number = 300): void {
        this.store.set(key, value);
        this.expiry.set(key, Date.now() + ttl * 1000);
        logger.info(`Redis SET ${key} (ttl=${ttl})`);
    }

    delete(key: string): boolean {
        this.expiry.delete(key);
        return this.store.delete(key);
    }

    clear(): number {
        const count = this.store.size;
        this.store.clear();
        this.expiry.clear();
        logger.info(`Redis FLUSHDB: ${count} keys`);
        return count;
    }

    incr(key: string, amount: number = 1): number {
        const current = (this.store.get(key) as number) ?? 0;
        const newVal = current + amount;
        this.store.set(key, newVal);
        return newVal;
    }
}
""",
)

# ─── src/cache/memoryCache.ts ───
w(
    "src/cache/memoryCache.ts",
    """\
/** In-memory LRU cache. */
import { getLogger } from '../utils/helpers';
import { BaseCache } from './base';

const logger = getLogger("cache.memory");

/** LRU memory cache. */
export class MemoryCache extends BaseCache {
    private store: Map<string, unknown> = new Map();
    private expiry: Map<string, number> = new Map();
    private maxSize: number;

    constructor(maxSize: number = 1000) {
        super("memory");
        this.maxSize = maxSize;
        logger.info(`MemoryCache created: maxSize=${maxSize}`);
    }

    get(key: string): unknown | null {
        if (this.store.has(key)) {
            const exp = this.expiry.get(key) ?? Infinity;
            if (Date.now() > exp) {
                this.store.delete(key);
                this.expiry.delete(key);
                this.misses++;
                return null;
            }
            this.hits++;
            // Move to end for LRU
            const val = this.store.get(key);
            this.store.delete(key);
            this.store.set(key, val);
            return val ?? null;
        }
        this.misses++;
        return null;
    }

    set(key: string, value: unknown, ttl: number = 300): void {
        if (this.store.has(key)) {
            this.store.delete(key);
        } else if (this.store.size >= this.maxSize) {
            const firstKey = this.store.keys().next().value;
            if (firstKey !== undefined) {
                this.store.delete(firstKey);
                this.expiry.delete(firstKey);
                logger.info(`LRU evicted: ${firstKey}`);
            }
        }
        this.store.set(key, value);
        this.expiry.set(key, Date.now() + ttl * 1000);
    }

    delete(key: string): boolean {
        this.expiry.delete(key);
        return this.store.delete(key);
    }

    clear(): number {
        const count = this.store.size;
        this.store.clear();
        this.expiry.clear();
        return count;
    }

    size(): number {
        return this.store.size;
    }
}
""",
)

# ─── src/validators/common.ts ───
w(
    "src/validators/common.ts",
    """\
/** Common validation utilities. */
import { getLogger } from '../utils/helpers';
import { ValidationError } from '../errors';

const logger = getLogger("validators.common");

const EMAIL_REGEX = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$/;

/** Validate email format. */
export function validateEmail(email: string): string {
    if (!email) throw new ValidationError("Email is required", "email");
    const clean = email.trim().toLowerCase();
    if (!EMAIL_REGEX.test(clean)) throw new ValidationError(`Invalid email: ${email}`, "email");
    return clean;
}

/** Validate string length. */
export function validateString(value: string, field: string, minLen: number = 1, maxLen: number = 255): string {
    if (!value) throw new ValidationError(`${field} is required`, field);
    const stripped = value.trim();
    if (stripped.length < minLen) throw new ValidationError(`${field} too short`, field);
    if (stripped.length > maxLen) throw new ValidationError(`${field} too long`, field);
    return stripped;
}

/** Validate positive number. */
export function validatePositiveNumber(value: unknown, field: string): number {
    const num = Number(value);
    if (isNaN(num)) throw new ValidationError(`${field} must be a number`, field);
    if (num <= 0) throw new ValidationError(`${field} must be positive`, field);
    return num;
}

/** Validate enum value. */
export function validateEnum(value: string, allowed: string[], field: string): string {
    if (!allowed.includes(value)) {
        throw new ValidationError(`Invalid ${field}: '${value}'. Allowed: ${allowed.join(", ")}`, field);
    }
    return value;
}
""",
)

# ─── src/validators/user.ts ───
w(
    "src/validators/user.ts",
    """\
/** User input validation. */
import { getLogger } from '../utils/helpers';
import { ValidationError } from '../errors';
import { validateEmail, validateString } from './common';

const logger = getLogger("validators.user");

/** Validate user data — name collision with validators/payment, api/v1/auth, api/v2/auth. */
export function validate(data: Record<string, unknown>): Record<string, unknown> {
    logger.info("Validating user data");
    if (!data["email"]) throw new ValidationError("Email required", "email");
    if (!data["name"]) throw new ValidationError("Name required", "name");
    const result: Record<string, unknown> = {};
    result["email"] = validateEmail(data["email"] as string);
    result["name"] = validateString(data["name"] as string, "name", 1, 100);
    if (data["password"]) {
        const pwd = data["password"] as string;
        if (pwd.length < 8) throw new ValidationError("Password too short", "password");
        result["password"] = pwd;
    }
    if (data["role"]) {
        const allowed = ["user", "admin", "moderator"];
        if (!allowed.includes(data["role"] as string)) throw new ValidationError("Invalid role", "role");
        result["role"] = data["role"];
    }
    return result;
}

/** Validate login data. */
export function validateLogin(data: Record<string, unknown>): { email: string; password: string } {
    if (!data["email"]) throw new ValidationError("Email required", "email");
    if (!data["password"]) throw new ValidationError("Password required", "password");
    return { email: validateEmail(data["email"] as string), password: data["password"] as string };
}
""",
)

# ─── src/validators/payment.ts ───
w(
    "src/validators/payment.ts",
    """\
/** Payment input validation. */
import { getLogger } from '../utils/helpers';
import { ValidationError } from '../errors';
import { validatePositiveNumber, validateEnum } from './common';

const logger = getLogger("validators.payment");

const CURRENCIES = ["USD", "EUR", "GBP", "JPY", "CAD"];
const METHODS = ["card", "bank_transfer", "wallet"];

/** Validate payment data — name collision with validators/user, api/v1/auth, api/v2/auth. */
export function validate(data: Record<string, unknown>): Record<string, unknown> {
    logger.info("Validating payment data");
    if (!data["amount"]) throw new ValidationError("Amount required", "amount");
    if (!data["currency"]) throw new ValidationError("Currency required", "currency");
    if (!data["user_id"]) throw new ValidationError("User ID required", "user_id");
    const result: Record<string, unknown> = {};
    result["amount"] = validatePositiveNumber(data["amount"], "amount");
    result["currency"] = validateEnum(data["currency"] as string, CURRENCIES, "currency");
    result["user_id"] = data["user_id"];
    result["payment_method"] = data["payment_method"] ? validateEnum(data["payment_method"] as string, METHODS, "payment_method") : "card";
    return result;
}

/** Validate refund data. */
export function validateRefund(data: Record<string, unknown>): Record<string, unknown> {
    if (!data["transaction_id"]) throw new ValidationError("Transaction ID required", "transaction_id");
    const result: Record<string, unknown> = { transaction_id: data["transaction_id"] };
    if (data["amount"]) result["amount"] = validatePositiveNumber(data["amount"], "amount");
    if (data["reason"]) result["reason"] = String(data["reason"]).substring(0, 500);
    return result;
}
""",
)

# ─── src/middleware/auth.ts ───
w(
    "src/middleware/auth.ts",
    """\
/** Auth middleware. */
import { getLogger, validateRequest } from '../utils/helpers';
import { validateToken, extractToken, TokenError } from '../auth/tokens';
import { AuthenticationError } from '../errors';

const logger = getLogger("middleware.auth");

/** Authentication middleware. */
export function authMiddleware(request: Record<string, unknown>): Record<string, unknown> {
    validateRequest(request);
    const publicPaths = ["/health", "/login", "/register"];
    if (publicPaths.includes(request["path"] as string)) return request;
    const token = extractToken(request as { headers?: Record<string, string> });
    if (!token) throw new AuthenticationError("Missing token");
    try {
        const claims = validateToken(token);
        return { ...request, user: claims, authenticated: true };
    } catch (e) {
        if (e instanceof TokenError) logger.warn("Token validation failed");
        throw new AuthenticationError("Invalid token");
    }
}
""",
)

# ─── src/middleware/rateLimit.ts ───
w(
    "src/middleware/rateLimit.ts",
    """\
/** Rate limiting middleware. */
import { getLogger, validateRequest } from '../utils/helpers';
import { RateLimitError } from '../errors';
import { CacheBackend } from '../cache/base';

const logger = getLogger("middleware.rateLimit");

/** Rate limiter. */
export class RateLimiter {
    constructor(private cache: CacheBackend, private limit: number = 100, private window: number = 60) {}

    check(key: string): { allowed: boolean; remaining: number } {
        const cacheKey = `ratelimit:${key}`;
        const current = this.cache.get(cacheKey) as number | null;
        if (current === null) {
            this.cache.set(cacheKey, 1, this.window);
            return { allowed: true, remaining: this.limit - 1 };
        }
        if (current >= this.limit) {
            logger.info(`Rate limit exceeded: ${key}`);
            return { allowed: false, remaining: 0 };
        }
        this.cache.set(cacheKey, current + 1, this.window);
        return { allowed: true, remaining: this.limit - current - 1 };
    }
}

/** Apply rate limiting. */
export function rateLimitMiddleware(request: Record<string, unknown>, cache: CacheBackend): Record<string, unknown> {
    validateRequest(request);
    const ip = (request["ip"] as string) ?? "unknown";
    const path = (request["path"] as string) ?? "/";
    const limiter = new RateLimiter(cache);
    const result = limiter.check(`${ip}:${path}`);
    if (!result.allowed) throw new RateLimitError(60);
    return { ...request, rateLimit: result };
}
""",
)

# ─── src/middleware/cors.ts ───
w(
    "src/middleware/cors.ts",
    """\
/** CORS middleware. */
import { getLogger, validateRequest } from '../utils/helpers';

const logger = getLogger("middleware.cors");

const DEFAULT_ORIGINS = ["http://localhost:3000", "https://app.example.com"];

/** CORS policy. */
export class CorsPolicy {
    constructor(
        public allowedOrigins: string[] = DEFAULT_ORIGINS,
        public allowedMethods: string[] = ["GET", "POST", "PUT", "DELETE"],
        public allowCredentials: boolean = true,
        public maxAge: number = 86400,
    ) {}

    isOriginAllowed(origin: string): boolean {
        return this.allowedOrigins.includes("*") || this.allowedOrigins.includes(origin);
    }

    getHeaders(origin: string): Record<string, string> {
        if (!this.isOriginAllowed(origin)) return {};
        return {
            "Access-Control-Allow-Origin": origin,
            "Access-Control-Allow-Methods": this.allowedMethods.join(", "),
            "Access-Control-Max-Age": String(this.maxAge),
        };
    }
}

/** Apply CORS. */
export function corsMiddleware(request: Record<string, unknown>, policy?: CorsPolicy): Record<string, unknown> {
    validateRequest(request);
    const cors = policy ?? new CorsPolicy();
    const origin = (request["origin"] as string) ?? "";
    if (origin) {
        const headers = cors.getHeaders(origin);
        if (!Object.keys(headers).length) logger.warn(`CORS rejected: ${origin}`);
        return { ...request, corsHeaders: headers };
    }
    return { ...request, corsHeaders: {} };
}
""",
)

# ─── src/middleware/logging.ts ───
w(
    "src/middleware/logging.ts",
    """\
/** Request logging middleware. */
import { getLogger, validateRequest, generateRequestId, maskSensitive } from '../utils/helpers';

const logger = getLogger("middleware.logging");

const SENSITIVE_FIELDS = ["password", "token", "secret", "apiKey"];

/** Log incoming requests. */
export function loggingMiddleware(request: Record<string, unknown>): Record<string, unknown> {
    validateRequest(request);
    const requestId = (request["requestId"] as string) ?? generateRequestId();
    const safe = maskSensitive(request, SENSITIVE_FIELDS);
    const method = request["method"] as string;
    const path = request["path"] as string;
    logger.info(`[${requestId}] ${method} ${path}`);
    return { ...request, requestId, startTime: Date.now() };
}

/** Log response. */
export function logResponse(request: Record<string, unknown>, status: number): void {
    const requestId = request["requestId"] as string;
    const start = (request["startTime"] as number) ?? Date.now();
    const duration = Date.now() - start;
    logger.info(`[${requestId}] -> ${status} (${duration}ms)`);
}
""",
)

# ─── src/api/v1/auth.ts ───
w(
    "src/api/v1/auth.ts",
    """\
/** API v1 authentication endpoints. */
import { getLogger, validateRequest, sanitizeInput } from '../../utils/helpers';
import { validateLogin } from '../../validators/user';
import { AuthenticationService } from '../../services/authService';
import { DatabaseConnection } from '../../database/connection';
import { EventDispatcher } from '../../events/dispatcher';
import { ValidationError } from '../../errors';

const logger = getLogger("api.v1.auth");

/** Validate v1 auth request — name collision. */
export function validate(request: Record<string, unknown>): Record<string, unknown> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    if (!body) throw new ValidationError("Body required");
    if (body["username"] && !body["email"]) {
        body["email"] = body["username"];
    }
    return body;
}

/** Handle v1 login — entry point for deep call chain. */
export async function handleLogin(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    logger.info("API v1 login");
    const body = validate(request);
    const loginData = validateLogin(body);
    const service = new AuthenticationService(db, events);
    service.initialize();
    const ip = (request["ip"] as string) ?? "unknown";
    const result = await service.authenticate(loginData.email, loginData.password, ip);
    return { status: 200, data: result };
}

/** Handle v1 register. */
export async function handleRegister(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    logger.info("API v1 register");
    const body = validate(request);
    return { status: 201, data: body };
}
""",
)

# ─── src/api/v1/payments.ts ───
w(
    "src/api/v1/payments.ts",
    """\
/** API v1 payment endpoints. */
import { getLogger, validateRequest } from '../../utils/helpers';
import { validate as validatePayment } from '../../validators/payment';
import { PaymentProcessor } from '../../services/payment/processor';
import { DatabaseConnection } from '../../database/connection';
import { EventDispatcher } from '../../events/dispatcher';

const logger = getLogger("api.v1.payments");

/** Create payment. */
export async function handleCreatePayment(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const paymentData = validatePayment(body);
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    const result = await processor.processPayment(
        paymentData["user_id"] as string,
        paymentData["amount"] as number,
        paymentData["currency"] as string,
    );
    return { status: 201, data: result };
}

/** Refund payment. */
export async function handleRefund(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    const result = await processor.refund(body["transaction_id"] as string, (body["reason"] as string) ?? "");
    return { status: 200, data: result };
}
""",
)

# ─── src/api/v1/users.ts ───
w(
    "src/api/v1/users.ts",
    """\
/** API v1 user endpoints. */
import { getLogger, validateRequest, paginate } from '../../utils/helpers';
import { validate as validateUser } from '../../validators/user';
import { DatabaseConnection } from '../../database/connection';
import { UserQueries } from '../../database/queries';
import { NotFoundError } from '../../errors';

const logger = getLogger("api.v1.users");

/** Get user by ID. */
export async function handleGetUser(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const params = request["params"] as Record<string, string>;
    const userId = params?.id ?? "";
    logger.info(`Getting user: ${userId}`);
    const user = await db.findById("users", userId);
    if (!user) throw new NotFoundError("User", userId);
    return { status: 200, data: user };
}

/** List users. */
export async function handleListUsers(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const params = request["params"] as Record<string, string>;
    const page = parseInt(params?.page ?? "1", 10);
    const queries = new UserQueries(db);
    const users = await queries.findActiveUsers(200);
    return { status: 200, data: paginate(users, page) };
}

/** Update user. */
export async function handleUpdateUser(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const params = request["params"] as Record<string, string>;
    const body = request["body"] as Record<string, unknown>;
    const validated = validateUser(body);
    await db.update("users", params?.id ?? "", validated);
    return { status: 200, data: validated };
}
""",
)

# ─── src/api/v2/auth.ts ───
w(
    "src/api/v2/auth.ts",
    """\
/** API v2 authentication endpoints — improved over v1. */
import { getLogger, validateRequest, sanitizeInput } from '../../utils/helpers';
import { validateLogin } from '../../validators/user';
import { AuthenticationService } from '../../services/authService';
import { DatabaseConnection } from '../../database/connection';
import { EventDispatcher } from '../../events/dispatcher';
import { ValidationError, AuthenticationError } from '../../errors';
import { generateToken, validateToken } from '../../auth/tokens';

const logger = getLogger("api.v2.auth");

/** Validate v2 auth request — name collision. */
export function validate(request: Record<string, unknown>): Record<string, unknown> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    if (!body) throw new ValidationError("Body required");
    if (!body["email"]) throw new ValidationError("Email required", "email");
    return body;
}

/** Handle v2 login with device tracking. */
export async function handleLogin(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    logger.info("API v2 login");
    const body = validate(request);
    const loginData = validateLogin(body);
    const service = new AuthenticationService(db, events);
    service.initialize();
    const ip = (request["ip"] as string) ?? "unknown";
    const result = await service.authenticate(loginData.email, loginData.password, ip);
    return { status: 200, data: { ...result, apiVersion: "v2" } };
}

/** Handle v2 token refresh. */
export async function handleTokenRefresh(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    logger.info("API v2 token refresh");
    validateRequest(request);
    const oldToken = (request["token"] as string) ?? "";
    if (!oldToken) throw new AuthenticationError("Refresh token required");
    const service = new AuthenticationService(db, events);
    service.initialize();
    const user = await service.verifyToken(oldToken);
    if (!user) throw new AuthenticationError("Invalid refresh token");
    const newToken = generateToken({ id: user["id"] as string, email: user["email"] as string, role: user["role"] as string });
    return { status: 200, data: { token: newToken, apiVersion: "v2" } };
}
""",
)

# ─── src/api/v2/payments.ts ───
w(
    "src/api/v2/payments.ts",
    """\
/** API v2 payment endpoints with webhook support. */
import { getLogger, validateRequest } from '../../utils/helpers';
import { validate as validatePayment } from '../../validators/payment';
import { PaymentProcessor } from '../../services/payment/processor';
import { DatabaseConnection } from '../../database/connection';
import { EventDispatcher } from '../../events/dispatcher';

const logger = getLogger("api.v2.payments");

/** Create payment with idempotency. */
export async function handleCreatePayment(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const headers = request["headers"] as Record<string, string>;
    const idempotencyKey = headers?.["Idempotency-Key"] ?? "";
    logger.info(`V2 create payment (idempotency=${idempotencyKey.substring(0, 12)})`);
    const paymentData = validatePayment(body);
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    const result = await processor.processPayment(
        paymentData["user_id"] as string,
        paymentData["amount"] as number,
        paymentData["currency"] as string,
    );
    return { status: 201, data: result };
}

/** Handle webhook. */
export async function handleWebhook(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const eventType = body["type"] as string;
    logger.info(`Webhook: ${eventType}`);
    return { status: 200, data: { acknowledged: true } };
}

/** Revenue report. */
export async function handleRevenueReport(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    return { status: 200, data: {} };
}
""",
)

# ─── src/routes/payments.ts ───
w(
    "src/routes/payments.ts",
    """\
/** Payment routes. */
import { getLogger, validateRequest } from '../utils/helpers';
import { PaymentProcessor } from '../services/payment/processor';
import { DatabaseConnection } from '../database/connection';
import { EventDispatcher } from '../events/dispatcher';
import { extractToken } from '../auth/tokens';

const logger = getLogger("routes.payments");

/** Create payment route. */
export async function createPaymentRoute(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    const result = await processor.processPayment(
        body["user_id"] as string,
        Number(body["amount"]),
        (body["currency"] as string) ?? "USD",
    );
    return { status: 201, data: result };
}

/** Refund route. */
export async function refundRoute(request: Record<string, unknown>, db: DatabaseConnection, events: EventDispatcher): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const processor = new PaymentProcessor(db, events);
    processor.initialize();
    const result = await processor.refund(body["transaction_id"] as string);
    return { status: 200, data: result };
}
""",
)

# ─── src/routes/users.ts ───
w(
    "src/routes/users.ts",
    """\
/** User routes. */
import { getLogger, validateRequest, paginate } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';
import { UserQueries } from '../database/queries';
import { validate as validateUser } from '../validators/user';
import { NotFoundError } from '../errors';

const logger = getLogger("routes.users");

/** Get user. */
export async function getUserRoute(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const params = request["params"] as Record<string, string>;
    const user = await db.findById("users", params?.id ?? "");
    if (!user) throw new NotFoundError("User", params?.id ?? "");
    return { status: 200, data: user };
}

/** List users. */
export async function listUsersRoute(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const queries = new UserQueries(db);
    const users = await queries.findActiveUsers(200);
    return { status: 200, data: paginate(users) };
}

/** Update user. */
export async function updateUserRoute(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const params = request["params"] as Record<string, string>;
    const body = request["body"] as Record<string, unknown>;
    const validated = validateUser(body);
    await db.update("users", params?.id ?? "", validated);
    return { status: 200, data: validated };
}
""",
)

# ─── src/routes/admin.ts ───
w(
    "src/routes/admin.ts",
    """\
/** Admin routes. */
import { getLogger, validateRequest } from '../utils/helpers';
import { AdminService } from '../auth/service';
import { extractToken } from '../auth/tokens';

const logger = getLogger("routes.admin");

/** Admin impersonate route. */
export async function impersonateRoute(request: Record<string, unknown>): Promise<Record<string, unknown>> {
    validateRequest(request);
    const token = extractToken(request as { headers?: Record<string, string> }) ?? "";
    const targetId = (request["params"] as Record<string, string>)?.userId ?? "";
    const admin = new AdminService();
    admin.initialize();
    const impersonationToken = await admin.impersonate(token, targetId);
    if (impersonationToken) {
        return { status: 200, data: { token: impersonationToken } };
    }
    return { status: 403, error: "Forbidden" };
}

/** List all users (admin). */
export async function listAllUsersRoute(request: Record<string, unknown>): Promise<Record<string, unknown>> {
    validateRequest(request);
    const token = extractToken(request as { headers?: Record<string, string> }) ?? "";
    const admin = new AdminService();
    admin.initialize();
    const users = await admin.listAllUsers(token);
    return { status: 200, data: users };
}
""",
)

# ─── src/routes/notifications.ts ───
w(
    "src/routes/notifications.ts",
    """\
/** Notification routes. */
import { getLogger, validateRequest } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';
import { NotificationManager } from '../services/notification/manager';

const logger = getLogger("routes.notifications");

/** Send notification. */
export async function sendNotificationRoute(request: Record<string, unknown>, db: DatabaseConnection): Promise<Record<string, unknown>> {
    validateRequest(request);
    const body = request["body"] as Record<string, unknown>;
    const manager = new NotificationManager(db);
    manager.initialize();
    const notification = await manager.send(
        body["user_id"] as string,
        (body["channel"] as string) ?? "email",
        body["subject"] as string,
        body["body"] as string,
    );
    return { status: 201, data: notification };
}
""",
)

# ─── src/tasks/emailTask.ts ───
w(
    "src/tasks/emailTask.ts",
    """\
/** Email background tasks. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';
import { EmailSender } from '../services/email/sender';

const logger = getLogger("tasks.email");

/** Send welcome email. */
export async function sendWelcomeEmail(userData: { email: string; name: string }, db: DatabaseConnection): Promise<boolean> {
    logger.info(`Sending welcome email to ${userData.email}`);
    const sender = new EmailSender(db);
    sender.initialize();
    return sender.sendTemplate(userData.email, "welcome", { name: userData.name });
}

/** Send password reset email. */
export async function sendPasswordResetEmail(email: string, resetLink: string, db: DatabaseConnection): Promise<boolean> {
    logger.info(`Sending password reset to ${email}`);
    const sender = new EmailSender(db);
    sender.initialize();
    return sender.sendTemplate(email, "password_reset", { link: resetLink });
}

/** Process email queue. */
export async function processEmailQueue(db: DatabaseConnection): Promise<{ sent: number; failed: number }> {
    logger.info("Processing email queue");
    const sender = new EmailSender(db);
    sender.initialize();
    // Process pending emails
    const pending = await db.findAll("notifications", { channel: "email", status: "pending" });
    let sent = 0;
    let failed = 0;
    for (const n of pending) {
        try {
            await sender.send(n["userId"] as string, n["subject"] as string, n["body"] as string);
            sent++;
        } catch {
            failed++;
        }
    }
    return { sent, failed };
}
""",
)

# ─── src/tasks/paymentTask.ts ───
w(
    "src/tasks/paymentTask.ts",
    """\
/** Payment background tasks. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';
import { PaymentQueries } from '../database/queries';
import { PaymentProcessor } from '../services/payment/processor';
import { EventDispatcher } from '../events/dispatcher';

const logger = getLogger("tasks.payment");

/** Process pending payments. */
export async function processPendingPayments(db: DatabaseConnection, events: EventDispatcher): Promise<{ processed: number; failed: number }> {
    logger.info("Processing pending payments");
    const queries = new PaymentQueries(db);
    const pending = await queries.findUserPayments("", "pending");
    let processed = 0;
    let failed = 0;
    for (const payment of pending) {
        try {
            await queries.updateStatus(payment["transactionId"] as string, "completed");
            processed++;
        } catch {
            await queries.updateStatus(payment["transactionId"] as string, "failed");
            failed++;
        }
    }
    return { processed, failed };
}

/** Reconcile payments. */
export async function reconcilePayments(db: DatabaseConnection, events: EventDispatcher): Promise<{ resolved: number }> {
    logger.info("Reconciling payments");
    const queries = new PaymentQueries(db);
    const processing = await queries.findUserPayments("", "processing");
    let resolved = 0;
    for (const payment of processing) {
        await queries.updateStatus(payment["transactionId"] as string, "completed");
        resolved++;
    }
    return { resolved };
}
""",
)

# ─── src/tasks/cleanupTask.ts ───
w(
    "src/tasks/cleanupTask.ts",
    """\
/** Cleanup background tasks. */
import { getLogger } from '../utils/helpers';
import { DatabaseConnection } from '../database/connection';
import { CacheBackend } from '../cache/base';

const logger = getLogger("tasks.cleanup");

/** Clean up expired sessions. */
export async function cleanupExpiredSessions(db: DatabaseConnection): Promise<number> {
    logger.info("Cleaning up expired sessions");
    const result = await db.executeQuery("UPDATE sessions SET expiredAt = ? WHERE expiredAt IS NULL AND createdAt < ?", [Date.now(), Date.now() - 7 * 86400 * 1000]);
    logger.info(`Expired ${result.affected} sessions`);
    return result.affected;
}

/** Clean up old events. */
export async function cleanupOldEvents(db: DatabaseConnection): Promise<number> {
    logger.info("Cleaning up old events");
    const result = await db.executeQuery("DELETE FROM events WHERE processedAt IS NOT NULL AND createdAt < ?", [Date.now() - 30 * 86400 * 1000]);
    return result.affected;
}

/** Flush cache. */
export function cleanupCache(cache: CacheBackend): number {
    logger.info("Running cache cleanup");
    return cache.clear();
}

/** Run all cleanup tasks. */
export async function runAllCleanup(db: DatabaseConnection, cache: CacheBackend): Promise<Record<string, number>> {
    const sessions = await cleanupExpiredSessions(db);
    const events = await cleanupOldEvents(db);
    const cacheEntries = cleanupCache(cache);
    logger.info("Cleanup complete");
    return { expiredSessions: sessions, oldEvents: events, cacheCleared: cacheEntries };
}
""",
)

# ─── src/config.ts ───
w(
    "src/config.ts",
    """\
/** Application configuration. */
import { getLogger } from './utils/helpers';

const logger = getLogger("config");

export interface AppConfig {
    port: number;
    host: string;
    dbDsn: string;
    redisHost: string;
    redisPort: number;
    jwtSecret: string;
    environment: string;
    logLevel: string;
    rateLimitPerMinute: number;
    corsOrigins: string[];
}

/** Load configuration from environment. */
export function loadConfig(): AppConfig {
    logger.info("Loading configuration");
    return {
        port: parseInt(process.env["PORT"] ?? "3000", 10),
        host: process.env["HOST"] ?? "0.0.0.0",
        dbDsn: process.env["DATABASE_URL"] ?? "sqlite://app.db",
        redisHost: process.env["REDIS_HOST"] ?? "localhost",
        redisPort: parseInt(process.env["REDIS_PORT"] ?? "6379", 10),
        jwtSecret: process.env["JWT_SECRET"] ?? "dev-secret",
        environment: process.env["NODE_ENV"] ?? "development",
        logLevel: process.env["LOG_LEVEL"] ?? "info",
        rateLimitPerMinute: parseInt(process.env["RATE_LIMIT"] ?? "100", 10),
        corsOrigins: (process.env["CORS_ORIGINS"] ?? "http://localhost:3000").split(","),
    };
}

/** Validate configuration. */
export function validateConfig(config: AppConfig): boolean {
    if (config.port < 1 || config.port > 65535) {
        logger.error(`Invalid port: ${config.port}`);
        return false;
    }
    if (!config.dbDsn) {
        logger.error("Database DSN is required");
        return false;
    }
    if (config.environment === "production" && config.jwtSecret === "dev-secret") {
        logger.warn("Using dev JWT secret in production!");
    }
    return true;
}
""",
)

# ─── src/app.ts ───
w(
    "src/app.ts",
    """\
/** Application entry point. */
import { getLogger } from './utils/helpers';
import { loadConfig, validateConfig } from './config';
import { ConnectionPool } from './database/pool';
import { DatabaseConnection } from './database/connection';
import { MigrationRunner } from './database/migrations';
import { EventDispatcher } from './events/dispatcher';
import { registerDefaultHandlers } from './events/handlers';
import { RedisCache } from './cache/redisCache';

const logger = getLogger("app");

/** Initialize the application. */
export async function initializeApp(): Promise<{
    db: DatabaseConnection;
    events: EventDispatcher;
    cache: RedisCache;
}> {
    logger.info("Initializing application");
    const config = loadConfig();
    if (!validateConfig(config)) {
        throw new Error("Invalid configuration");
    }

    // Database
    const pool = new ConnectionPool(config.dbDsn);
    pool.initialize();
    const db = new DatabaseConnection(pool);

    // Migrations
    const migrations = new MigrationRunner(db);
    await migrations.runPending();

    // Events
    const events = new EventDispatcher();
    registerDefaultHandlers(events);

    // Cache
    const cache = new RedisCache(config.redisHost, config.redisPort);

    logger.info("Application initialized");
    return { db, events, cache };
}
""",
)

print("TypeScript fixture generation complete")
