# Configuration Management Architecture Specification

## Overview

This document defines the comprehensive configuration management architecture for the Gemini-Flow project, ensuring centralized, secure, and scalable configuration handling across all environments. The architecture supports the SPARC methodology requirements with emphasis on security, modularity, testability, and maintainability.

## Core Configuration Principles

### 1. **Centralized Management**
- Single source of truth for all configuration
- Unified access patterns across modules
- Consistent validation and transformation

### 2. **Environment Isolation**
- Strict separation between environments
- Environment-specific overrides
- Secure credential management

### 3. **Security First**
- No hardcoded credentials or secrets
- Encrypted configuration storage
- Access control and audit logging

### 4. **Dynamic Updates**
- Runtime configuration reloading
- Hot configuration updates
- Zero-downtime configuration changes

### 5. **Validation and Safety**
- Schema-based validation
- Type-safe configuration access
- Safe fallback mechanisms

## Configuration Architecture Overview

### 1. **Configuration Hierarchy**

```
┌─────────────────────────────────────┐
│         Environment Variables       │
│            (Highest Priority)       │
└─────────────────┬───────────────────┘
                  │
┌─────────────────▼───────────────────┐
│         Configuration Files         │
│     (JSON, YAML, TOML, ENV)        │
└─────────────────┬───────────────────┘
                  │
┌─────────────────▼───────────────────┐
│         Remote Configuration        │
│     (Database, KV Store, API)      │
│     (Medium Priority)              │
└─────────────────┬───────────────────┘
                  │
┌─────────────────▼───────────────────┐
│         Default Configuration       │
│         (Lowest Priority)          │
└─────────────────────────────────────┘
```

### 2. **Configuration Categories**

| Category | Description | Examples | Security Level |
|----------|-------------|----------|----------------|
| **Core** | Fundamental application settings | App metadata, ports, timeouts | Low |
| **Security** | Authentication and authorization | API keys, certificates, tokens | High |
| **Integrations** | External service configurations | Google AI, MCP servers, DB | Medium |
| **Infrastructure** | Runtime environment settings | Resource limits, scaling | Low |
| **Performance** | Performance tuning parameters | Cache settings, concurrency | Low |
| **Monitoring** | Observability configurations | Log levels, metrics endpoints | Low |

## Configuration Storage Architecture

### 1. **Storage Providers**

#### 1.1 Environment Variables Provider
**Purpose**: Runtime configuration overrides
**Implementation**:
```typescript
interface EnvironmentProvider {
  get(key: string): Promise<string | undefined>;
  getAll(prefix?: string): Promise<Map<string, string>>;
  validateKey(key: string): boolean;
}
```

**Security Features**:
- Automatic credential detection
- Value encryption validation
- Access logging

#### 1.2 File-Based Provider
**Purpose**: Static configuration storage
**Implementation**:
```typescript
interface FileProvider {
  load(filePath: string): Promise<Configuration>;
  watch(filePath: string, callback: ChangeCallback): Subscription;
  validate(filePath: string, schema: ConfigSchema): Promise<ValidationResult>;
}
```

**Supported Formats**:
- JSON (primary)
- YAML (human-readable)
- TOML (simple configs)
- ENV (legacy support)

#### 1.3 Remote Provider
**Purpose**: Dynamic configuration management
**Implementation**:
```typescript
interface RemoteProvider {
  get(key: string): Promise<any>;
  set(key: string, value: any): Promise<void>;
  watch(key: string, callback: ChangeCallback): Subscription;
  refresh(): Promise<void>;
}
```

**Providers**:
- Database (primary)
- Redis/KV Store (cache)
- HTTP API (external)
- Cloud Services (AWS, GCP)

### 2. **Configuration Schema System**

#### 2.1 Schema Definition
```typescript
interface ConfigSchema {
  type: 'object' | 'string' | 'number' | 'boolean' | 'array';
  required?: boolean;
  default?: any;
  validation?: ValidationRule[];
  transform?: TransformFunction;
  description?: string;
  sensitive?: boolean;
  deprecated?: boolean;
}
```

#### 2.2 Schema Validation
```typescript
interface SchemaValidator {
  validate(config: any, schema: ConfigSchema): Promise<ValidationResult>;
  sanitize(config: any, schema: ConfigSchema): Promise<any>;
  migrate(config: any, fromVersion: string, toVersion: string): Promise<any>;
}
```

### 3. **Configuration Loader Architecture**

#### 3.1 Loader Chain
```
Environment Loader → File Loader → Remote Loader → Default Loader
                    ↓
              Schema Validation
                    ↓
             Value Transformation
                    ↓
              Security Processing
                    ↓
           Configuration Assembly
```

#### 3.2 Loader Implementation
```typescript
interface ConfigurationLoader {
  load(sources: ConfigSource[]): Promise<Configuration>;
  reload(): Promise<Configuration>;
  validate(config: Configuration): Promise<ValidationResult>;
  getMetadata(): ConfigurationMetadata;
}
```

## Environment-Specific Configuration

### 1. **Environment Architecture**

#### 1.1 Environment Hierarchy
```
Development → Testing → Staging → Production
     ↓          ↓         ↓         ↓
  Local Dev  Integration  Pre-prod  Live
```

#### 1.2 Environment Configuration Strategy

**Development**:
- Local overrides enabled
- Debug logging enabled
- Relaxed security for development
- Hot reloading enabled

**Testing**:
- Test-specific configurations
- Mock data isolation
- Performance profiling
- Test reporting integration

**Staging**:
- Production-like configuration
- Load testing setup
- Monitoring validation
- Pre-deployment validation

**Production**:
- Maximum security
- Performance optimization
- Monitoring and alerting
- Audit logging enabled

### 2. **Environment Variable Management**

#### 2.1 Environment Variable Schema
```typescript
interface EnvironmentSchema {
  name: string;
  type: 'string' | 'number' | 'boolean' | 'json';
  required: boolean;
  default?: any;
  validation?: ValidationRule[];
  description: string;
  sensitive: boolean;
  environments: string[];
}
```

#### 2.2 Variable Validation
```typescript
interface EnvironmentValidator {
  validateVariable(name: string, value: string): Promise<ValidationResult>;
  detectSensitiveData(value: string): boolean;
  sanitizeValue(value: string): string;
}
```

## Configuration Security Architecture

### 1. **Secret Management**

#### 1.1 Secret Storage
```typescript
interface SecretManager {
  getSecret(key: string): Promise<string>;
  setSecret(key: string, value: string): Promise<void>;
  rotateSecret(key: string): Promise<string>;
  deleteSecret(key: string): Promise<void>;
}
```

**Storage Options**:
- Environment variables (primary)
- Secure key-value stores
- Cloud secret managers
- Hardware security modules

#### 1.2 Secret Encryption
```typescript
interface SecretEncryption {
  encrypt(plaintext: string): Promise<EncryptedSecret>;
  decrypt(encryptedSecret: EncryptedSecret): Promise<string>;
  generateKey(): Promise<CryptographicKey>;
  rotateKey(oldKey: CryptographicKey): Promise<CryptographicKey>;
}
```

### 2. **Access Control**

#### 2.1 Configuration Access Control
```typescript
interface ConfigurationAccessControl {
  canRead(key: string, user: User): Promise<boolean>;
  canWrite(key: string, user: User): Promise<boolean>;
  canDelete(key: string, user: User): Promise<boolean>;
  logAccess(key: string, user: User, action: AccessAction): Promise<void>;
}
```

#### 2.2 Role-Based Access Control
```typescript
interface RBACManager {
  grantPermission(role: string, resource: string, permission: Permission): Promise<void>;
  revokePermission(role: string, resource: string, permission: Permission): Promise<void>;
  checkPermission(user: User, resource: string, permission: Permission): Promise<boolean>;
}
```

## Dynamic Configuration Management

### 1. **Configuration Watching**

#### 1.1 File System Watcher
```typescript
interface FileWatcher {
  watch(filePath: string): Subscription;
  unwatch(subscription: Subscription): Promise<void>;
  onChange(callback: ChangeCallback): void;
  onError(callback: ErrorCallback): void;
}
```

#### 1.2 Remote Configuration Watcher
```typescript
interface RemoteWatcher {
  watch(key: string): Subscription;
  unwatch(subscription: Subscription): Promise<void>;
  setPollingInterval(interval: number): void;
  forceRefresh(): Promise<void>;
}
```

### 2. **Hot Reloading Architecture**

#### 2.1 Reload Strategy
```typescript
interface ConfigurationReloader {
  reload(): Promise<Configuration>;
  validateReload(config: Configuration): Promise<ValidationResult>;
  applyReload(config: Configuration): Promise<void>;
  rollback(): Promise<void>;
}
```

#### 2.2 Service Impact Assessment
```typescript
interface ImpactAssessor {
  assessImpact(config: Configuration): Promise<ImpactAnalysis>;
  canReloadSafely(config: Configuration): Promise<boolean>;
  getAffectedServices(config: Configuration): Promise<string[]>;
  planReload(config: Configuration): Promise<ReloadPlan>;
}
```

## Configuration Validation Architecture

### 1. **Validation Pipeline**

#### 1.1 Schema Validation
```typescript
interface SchemaValidator {
  validate(config: any, schema: ConfigSchema): Promise<ValidationResult>;
  getValidationErrors(): ValidationError[];
  fixValidationErrors(config: any): Promise<any>;
}
```

#### 1.2 Business Rule Validation
```typescript
interface BusinessRuleValidator {
  validateBusinessRules(config: Configuration): Promise<ValidationResult>;
  validateDependencies(config: Configuration): Promise<ValidationResult>;
  validateEnvironmentConstraints(config: Configuration): Promise<ValidationResult>;
}
```

### 2. **Validation Types**

#### 2.1 Type Validation
- String length constraints
- Number range validation
- Boolean value validation
- Array item validation

#### 2.2 Format Validation
- Email format validation
- URL format validation
- IP address validation
- JSON structure validation

#### 2.3 Business Logic Validation
- Dependency validation
- Resource limit validation
- Performance constraint validation
- Security policy validation

## Configuration Versioning and Migration

### 1. **Version Management**

#### 1.1 Version Schema
```typescript
interface ConfigurationVersion {
  major: number;
  minor: number;
  patch: number;
  timestamp: Date;
  author: string;
  description: string;
  breakingChanges: boolean;
  migrationGuide?: string;
}
```

#### 1.2 Version Comparison
```typescript
interface VersionComparator {
  compare(v1: ConfigurationVersion, v2: ConfigurationVersion): VersionComparison;
  isBreakingChange(from: ConfigurationVersion, to: ConfigurationVersion): boolean;
  getMigrationPath(from: ConfigurationVersion, to: ConfigurationVersion): MigrationPath;
}
```

### 2. **Migration System**

#### 2.1 Migration Execution
```typescript
interface ConfigurationMigrator {
  migrate(config: any, fromVersion: string, toVersion: string): Promise<any>;
  validateMigration(config: any, migration: Migration): Promise<ValidationResult>;
  rollbackMigration(config: any, migration: Migration): Promise<any>;
}
```

#### 2.2 Migration Safety
```typescript
interface MigrationSafety {
  canMigrateSafely(config: any, migration: Migration): Promise<boolean>;
  backupConfiguration(config: any): Promise<Backup>;
  restoreConfiguration(backup: Backup): Promise<void>;
  validateMigrationResult(config: any): Promise<ValidationResult>;
}
```

## Configuration Testing Architecture

### 1. **Test Environment Setup**

#### 1.1 Configuration Test Harness
```typescript
interface ConfigurationTestHarness {
  setupTestEnvironment(config: TestConfiguration): Promise<TestEnvironment>;
  loadTestConfiguration(config: TestConfiguration): Promise<Configuration>;
  validateTestConfiguration(config: Configuration): Promise<ValidationResult>;
  cleanupTestEnvironment(): Promise<void>;
}
```

#### 1.2 Test Data Generation
```typescript
interface TestDataGenerator {
  generateValidConfig(schema: ConfigSchema): Promise<any>;
  generateInvalidConfig(schema: ConfigSchema): Promise<any>;
  generateEdgeCaseConfig(schema: ConfigSchema): Promise<any>;
  generatePerformanceTestConfig(schema: ConfigSchema): Promise<any>;
}
```

### 2. **Configuration Testing Strategies**

#### 2.1 Unit Testing
- Schema validation testing
- Value transformation testing
- Error handling testing
- Security validation testing

#### 2.2 Integration Testing
- Multi-source configuration testing
- Environment-specific testing
- Migration testing
- Performance testing

#### 2.3 End-to-End Testing
- Full configuration lifecycle testing
- Cross-environment testing
- Security testing
- Monitoring integration testing

## Configuration Performance Architecture

### 1. **Caching Strategy**

#### 1.1 Multi-Level Caching
```typescript
interface ConfigurationCache {
  get(key: string): Promise<any>;
  set(key: string, value: any, ttl?: number): Promise<void>;
  invalidate(key: string): Promise<void>;
  clear(): Promise<void>;
}
```

**Cache Levels**:
1. **Memory Cache**: Fastest access, per-instance
2. **Distributed Cache**: Shared across instances
3. **Persistent Cache**: Long-term storage

#### 1.2 Cache Invalidation
```typescript
interface CacheInvalidationStrategy {
  invalidateByKey(key: string): Promise<void>;
  invalidateByPattern(pattern: string): Promise<void>;
  invalidateByDependency(dependency: string): Promise<void>;
  getInvalidationMetrics(): Promise<InvalidationMetrics>;
}
```

### 2. **Performance Monitoring**

#### 2.1 Performance Metrics
```typescript
interface ConfigurationPerformanceMonitor {
  recordLoadTime(source: string, duration: number): void;
  recordValidationTime(schema: string, duration: number): void;
  recordCacheHitRate(): void;
  getPerformanceMetrics(): Promise<PerformanceMetrics>;
}
```

#### 2.2 Performance Optimization
```typescript
interface ConfigurationOptimizer {
  optimizeCacheStrategy(): Promise<OptimizationResult>;
  optimizeLoadingStrategy(): Promise<OptimizationResult>;
  optimizeValidationStrategy(): Promise<OptimizationResult>;
  getOptimizationRecommendations(): Promise<Recommendation[]>;
}
```

## Configuration Monitoring and Observability

### 1. **Monitoring Integration**

#### 1.1 Configuration Health Monitoring
```typescript
interface ConfigurationHealthMonitor {
  checkConfigurationHealth(): Promise<HealthStatus>;
  checkSchemaHealth(): Promise<HealthStatus>;
  checkSecurityHealth(): Promise<HealthStatus>;
  getHealthReport(): Promise<HealthReport>;
}
```

#### 1.2 Configuration Change Tracking
```typescript
interface ConfigurationChangeTracker {
  trackChange(key: string, oldValue: any, newValue: any): Promise<void>;
  getChangeHistory(key: string): Promise<ChangeHistory>;
  getConfigurationDrift(): Promise<DriftReport>;
}
```

### 2. **Observability Features**

#### 2.1 Metrics Collection
```typescript
interface ConfigurationMetricsCollector {
  collectLoadMetrics(): Promise<LoadMetrics>;
  collectValidationMetrics(): Promise<ValidationMetrics>;
  collectSecurityMetrics(): Promise<SecurityMetrics>;
  collectPerformanceMetrics(): Promise<PerformanceMetrics>;
}
```

#### 2.2 Alerting Integration
```typescript
interface ConfigurationAlertManager {
  setupAlerts(): Promise<void>;
  handleConfigurationError(error: ConfigurationError): Promise<void>;
  handleSecurityViolation(violation: SecurityViolation): Promise<void>;
  sendNotification(notification: ConfigurationNotification): Promise<void>;
}
```

## Configuration Deployment Architecture

### 1. **Deployment Strategies**

#### 1.1 Blue-Green Deployment
```typescript
interface BlueGreenDeployment {
  deployToBlue(config: Configuration): Promise<void>;
  switchToBlue(): Promise<void>;
  switchToGreen(): Promise<void>;
  rollback(): Promise<void>;
}
```

#### 1.2 Rolling Update Deployment
```typescript
interface RollingUpdateDeployment {
  deployToInstances(config: Configuration, instances: string[]): Promise<void>;
  validateDeployment(instances: string[]): Promise<ValidationResult>;
  rollbackInstances(instances: string[]): Promise<void>;
}
```

### 2. **Configuration Pipeline**

#### 2.1 CI/CD Integration
```typescript
interface ConfigurationPipeline {
  validateConfiguration(config: Configuration): Promise<ValidationResult>;
  testConfiguration(config: Configuration): Promise<TestResult>;
  deployConfiguration(config: Configuration, environment: string): Promise<DeploymentResult>;
  rollbackConfiguration(environment: string): Promise<void>;
}
```

#### 2.2 Configuration as Code
```typescript
interface ConfigurationAsCode {
  generateConfiguration(schema: ConfigSchema): Promise<Configuration>;
  validateConfigurationCode(code: string): Promise<ValidationResult>;
  deployConfigurationCode(code: string, environment: string): Promise<DeploymentResult>;
}
```

## Configuration Security Best Practices

### 1. **Secret Management**

#### 1.1 Secret Detection
```typescript
interface SecretDetector {
  detectSecrets(config: Configuration): Promise<SecretDetectionResult>;
  maskSecrets(config: Configuration): Promise<Configuration>;
  validateSecretUsage(config: Configuration): Promise<ValidationResult>;
}
```

#### 1.2 Secret Rotation
```typescript
interface SecretRotationManager {
  rotateSecret(key: string): Promise<void>;
  scheduleRotation(key: string, schedule: RotationSchedule): Promise<void>;
  validateRotation(key: string): Promise<ValidationResult>;
}
```

### 2. **Access Control**

#### 2.1 Least Privilege Principle
```typescript
interface LeastPrivilegeManager {
  analyzePermissions(config: Configuration): Promise<PermissionAnalysis>;
  minimizePermissions(config: Configuration): Promise<Configuration>;
  validatePermissions(config: Configuration): Promise<ValidationResult>;
}
```

#### 2.2 Audit Logging
```typescript
interface ConfigurationAuditLogger {
  logAccess(key: string, user: User, action: AccessAction): Promise<void>;
  logChange(key: string, oldValue: any, newValue: any, user: User): Promise<void>;
  logSecurityEvent(event: SecurityEvent): Promise<void>;
  queryAuditLog(criteria: AuditQuery): Promise<AuditEntry[]>;
}
```

## Configuration API Design

### 1. **Configuration Service API**

#### 1.1 Service Interface
```typescript
interface ConfigurationService {
  get(key: string): Promise<any>;
  getAll(prefix?: string): Promise<Map<string, any>>;
  set(key: string, value: any): Promise<void>;
  delete(key: string): Promise<void>;
  reload(): Promise<void>;
  validate(): Promise<ValidationResult>;
}
```

#### 1.2 Advanced Features
```typescript
interface AdvancedConfigurationService {
  watch(key: string, callback: ChangeCallback): Subscription;
  batchGet(keys: string[]): Promise<Map<string, any>>;
  batchSet(updates: Map<string, any>): Promise<void>;
  transaction(updates: Map<string, any>): Promise<TransactionResult>;
}
```

### 2. **Management API**

#### 2.1 Administrative Interface
```typescript
interface ConfigurationManagementAPI {
  listConfigurations(): Promise<ConfigurationSummary[]>;
  getConfigurationDetails(key: string): Promise<ConfigurationDetails>;
  updateConfiguration(key: string, value: any): Promise<void>;
  deleteConfiguration(key: string): Promise<void>;
  validateAllConfigurations(): Promise<ValidationResult[]>;
}
```

#### 2.2 Monitoring Interface
```typescript
interface ConfigurationMonitoringAPI {
  getHealthStatus(): Promise<HealthStatus>;
  getMetrics(): Promise<ConfigurationMetrics>;
  getAlerts(): Promise<ConfigurationAlert[]>;
  getPerformanceReport(): Promise<PerformanceReport>;
}
```

## Configuration Schema Registry

### 1. **Schema Management**

#### 1.1 Schema Registry
```typescript
interface SchemaRegistry {
  registerSchema(schema: ConfigSchema): Promise<SchemaId>;
  getSchema(schemaId: SchemaId): Promise<ConfigSchema>;
  updateSchema(schemaId: SchemaId, schema: ConfigSchema): Promise<void>;
  deleteSchema(schemaId: SchemaId): Promise<void>;
}
```

#### 1.2 Schema Validation
```typescript
interface SchemaValidator {
  validateSchema(schema: ConfigSchema): Promise<ValidationResult>;
  validateConfiguration(config: any, schema: ConfigSchema): Promise<ValidationResult>;
  migrateConfiguration(config: any, fromSchema: ConfigSchema, toSchema: ConfigSchema): Promise<any>;
}
```

### 2. **Schema Evolution**

#### 2.1 Schema Versioning
```typescript
interface SchemaVersionManager {
  createVersion(schema: ConfigSchema): Promise<SchemaVersion>;
  getVersionHistory(schemaId: SchemaId): Promise<SchemaVersion[]>;
  migrateBetweenVersions(config: any, fromVersion: SchemaVersion, toVersion: SchemaVersion): Promise<any>;
}
```

#### 2.2 Compatibility Checking
```typescript
interface SchemaCompatibilityChecker {
  checkCompatibility(schema1: ConfigSchema, schema2: ConfigSchema): Promise<CompatibilityResult>;
  getBreakingChanges(schema1: ConfigSchema, schema2: ConfigSchema): Promise<BreakingChange[]>;
  generateMigrationPlan(schema1: ConfigSchema, schema2: ConfigSchema): Promise<MigrationPlan>;
}
```

## Configuration Backup and Recovery

### 1. **Backup Strategy**

#### 1.1 Backup Management
```typescript
interface ConfigurationBackupManager {
  createBackup(): Promise<BackupId>;
  restoreBackup(backupId: BackupId): Promise<void>;
  listBackups(): Promise<BackupSummary[]>;
  deleteBackup(backupId: BackupId): Promise<void>;
}
```

#### 1.2 Recovery Procedures
```typescript
interface ConfigurationRecoveryManager {
  detectConfigurationDrift(): Promise<DriftReport>;
  recoverFromDrift(drift: DriftReport): Promise<void>;
  recoverFromCorruption(): Promise<void>;
  validateRecovery(): Promise<ValidationResult>;
}
```

### 2. **Disaster Recovery**

#### 2.1 DR Planning
```typescript
interface ConfigurationDRPlanner {
  planDisasterRecovery(): Promise<DRPlan>;
  validateDRPlan(plan: DRPlan): Promise<ValidationResult>;
  executeDRPlan(plan: DRPlan): Promise<void>;
  testDRPlan(plan: DRPlan): Promise<TestResult>;
}
```

#### 2.2 Failover Management
```typescript
interface ConfigurationFailoverManager {
  initiateFailover(): Promise<void>;
  monitorFailover(): Promise<FailoverStatus>;
  completeFailover(): Promise<void>;
  rollbackFailover(): Promise<void>;
}
```

## Implementation Roadmap

### Phase 1: Foundation (Weeks 1-2)
1. **Core Configuration Service**
   - Basic configuration loading
   - Environment variable support
   - Schema validation framework
   - Security integration foundation

2. **Storage Providers**
   - File-based provider implementation
   - Environment provider implementation
   - Remote provider foundation
   - Provider abstraction layer

### Phase 2: Security and Validation (Weeks 3-4)
1. **Security Implementation**
   - Secret management system
   - Access control implementation
   - Encryption services
   - Audit logging system

2. **Validation System**
   - Schema registry implementation
   - Validation pipeline
   - Migration system
   - Testing framework

### Phase 3: Advanced Features (Weeks 5-6)
1. **Dynamic Configuration**
   - Hot reloading implementation
   - Configuration watching
   - Service impact assessment
   - Performance optimization

2. **Monitoring and Observability**
   - Health monitoring
   - Metrics collection
   - Alerting integration
   - Performance monitoring

### Phase 4: Production Readiness (Weeks 7-8)
1. **Production Features**
   - Backup and recovery
   - Disaster recovery planning
   - Performance optimization
   - Security hardening

2. **Management Tools**
   - Configuration API
   - Management interface
   - Deployment integration
   - Documentation completion

## Success Metrics

- **Configuration Loading Time**: <100ms for all configurations
- **Schema Validation Coverage**: 100% of configuration values
- **Security Compliance**: Zero hardcoded credentials
- **Environment Isolation**: Complete separation between environments
- **Hot Reload Success Rate**: >99.9% successful reloads
- **Configuration Backup Success Rate**: 100% successful backups
- **Performance Impact**: <1% overhead on application performance

---

**Next Steps**: Review this configuration management architecture specification and provide feedback on security considerations, validation strategies, or deployment approaches before proceeding to build and deployment architecture.