# Complexity Audit Report

**Branch**: fix/tech-debt-v0.3.2
**Base**: main
**Date**: 2025-12-08 20:47:00

---

## Summary

This branch contains **technical debt reduction** changes focused on:
1. Adding explicit row types for database access (type safety)
2. Making MAX_DEPENDENCY_CHAIN_DEPTH configurable
3. Documentation corrections
4. Replacing `getQueueStats()` with `getQueueSize()` (performance)
5. Adding CHECK constraint on resolution column (defense-in-depth)

---

## [RED] Issues in Your Changes (BLOCKING)

**No blocking issues found.**

The changes in this branch are clean refactoring that improve code quality:
- Type definitions are simple interfaces
- New options interface follows existing patterns
- Method simplification reduces complexity

---

## [WARNING] Issues in Code You Touched (Should Fix)

### 1. **TaskRow Interface - High Field Count**
**File**: `/workspace/delegate/src/implementations/task-repository.ts:17-43`
**Severity**: MEDIUM
**Type**: Code Smell - Large Interface

```typescript
interface TaskRow {
  readonly id: string;
  readonly prompt: string;
  readonly status: string;
  // ... 24 more fields (27 total)
}
```

**Analysis**: The `TaskRow` interface has 27 fields, which mirrors the database schema. While this is intentional (database row mapping), it indicates the `tasks` table has grown large.

**Recommendation**: Not blocking - this is a faithful representation of the database schema. Consider in future refactoring whether task metadata (worktree config, PR config) should be normalized into separate tables.

---

### 2. **rowToTask Method - High Mapping Complexity**
**File**: `/workspace/delegate/src/implementations/task-repository.ts:232-259`
**Severity**: LOW
**Type**: Cognitive Complexity

```typescript
private rowToTask(row: TaskRow): Task {
  return {
    id: row.id as TaskId,
    prompt: row.prompt,
    status: row.status as TaskStatus,
    // ... 24 more field mappings
  };
}
```

**Analysis**: The `rowToTask` method has 27 field mappings. This is inherent to the data model but adds cognitive load when reading.

**Lines modified in this branch**: 240-241 (type casts added)
```typescript
worktreeCleanup: (row.worktree_cleanup || 'auto') as 'auto' | 'keep' | 'delete',
mergeStrategy: (row.merge_strategy || 'pr') as 'auto' | 'pr' | 'manual' | 'patch',
```

**Impact**: The changes IMPROVE type safety by adding explicit type casts instead of implicit string types.

---

### 3. **addDependencies Transaction Function - Moderate Complexity**
**File**: `/workspace/delegate/src/implementations/dependency-repository.ts:189-247`
**Severity**: LOW
**Type**: Cyclomatic Complexity (~8)

```typescript
const addDependenciesTransaction = this.db.transaction((taskId, dependsOn) => {
  // Validation 1: Check task exists
  if (taskExistsResult.count === 0) { throw ... }
  
  // Validation 2: Check dependency count
  if (existingDepsCount + dependsOn.length > MAX) { throw ... }
  
  // Validation 3: Check all targets exist (loop)
  for (const depId of dependsOn) {
    if (depExistsResult.count === 0) { throw ... }
  }
  
  // Validation 4: Check for duplicates (loop)
  for (const depId of dependsOn) {
    if (existsResult.count > 0) { throw ... }
  }
  
  // Insert (loop)
  for (const depId of dependsOn) { ... }
});
```

**Analysis**: 
- Cyclomatic complexity: ~8 (acceptable, under 10 threshold)
- Function length: ~60 lines (slightly over 50-line guideline)
- Nesting depth: 2 (acceptable)

**Mitigation**: The complexity is justified - it implements TOCTOU-safe atomic validation. Breaking this up would compromise atomicity guarantees.

---

### 4. **resolveDependencies Method - Moderate Cognitive Load**
**File**: `/workspace/delegate/src/services/handlers/dependency-handler.ts:428-532`
**Severity**: LOW
**Type**: Function Length (~105 lines)

```typescript
private async resolveDependencies(
  completedTaskId: TaskId,
  resolution: 'completed' | 'failed' | 'cancelled'
): Promise<Result<void>> {
  // Get dependents (10 lines)
  // Early exit if none (5 lines)
  // Batch resolve (15 lines)
  // Loop: emit events + check unblocked (50 lines)
  return ok(undefined);
}
```

**Analysis**:
- Function length: ~105 lines (exceeds 50-line guideline)
- Cyclomatic complexity: ~6 (acceptable)
- The loop body at lines 481-528 contains significant logic

**Recommendation**: Consider extracting the loop body into a separate `processResolvedDependency()` method. Not blocking as the current structure is readable and well-commented.

---

### 5. **handleTaskDelegated Method - Well-Decomposed**
**File**: `/workspace/delegate/src/services/handlers/dependency-handler.ts:307-362`
**Severity**: NONE (Positive Finding)

The `handleTaskDelegated` method demonstrates GOOD decomposition:
- `validateSingleDependency()` - pure validation
- `handleValidationFailure()` - error handling
- `handleDatabaseFailure()` - error handling
- `updateGraphAfterPersistence()` - graph updates
- `emitDependencyAddedEvents()` - event emission

This branch maintains this clean architecture.

---

## [INFO] Pre-existing Issues (Not Blocking)

### 1. **DependencyHandler Class Size**
**File**: `/workspace/delegate/src/services/handlers/dependency-handler.ts`
**Severity**: INFORMATIONAL
**Type**: Class Complexity

**Analysis**: The `DependencyHandler` class is 534 lines. While large, it:
- Has a single responsibility (dependency management)
- Uses proper decomposition (extracted helper methods)
- Well-documented with architecture comments

**Recommendation**: Monitor growth. If it exceeds 700 lines, consider extracting validation logic into a `DependencyValidator` class.

---

### 2. **QueueHandler Deprecated Methods**
**File**: `/workspace/delegate/src/services/handlers/queue-handler.ts:228-282`
**Severity**: INFORMATIONAL
**Type**: Technical Debt

```typescript
/**
 * DEPRECATED: Use NextTaskQuery event instead
 * @deprecated This method will be removed - use event-driven pattern
 */
async getNextTask(): Promise<Result<any>> { ... }

/**
 * DEPRECATED: Use RequeueTask event instead
 * @deprecated This method will be removed - use event-driven pattern
 */
async requeueTask(task: Task): Promise<Result<void>> { ... }
```

**Analysis**: Two deprecated methods remain in the codebase.

**Recommendation**: Track removal in future tech debt sprint.

---

### 3. **Database Migration Complexity**
**File**: `/workspace/delegate/src/implementations/database.ts:274-314`
**Severity**: INFORMATIONAL
**Type**: Migration Complexity

The new migration (v2) uses table recreation pattern:
```sql
CREATE TABLE task_dependencies_new ...
INSERT INTO task_dependencies_new SELECT * FROM task_dependencies;
DROP TABLE task_dependencies;
ALTER TABLE task_dependencies_new RENAME TO task_dependencies;
-- Recreate 5 indexes
```

**Analysis**: This is the correct pattern for SQLite (doesn't support ALTER TABLE ADD CHECK). However, it:
- Is a destructive migration (cannot rollback)
- Could fail on large tables with locks

**Mitigation**: Transaction wrapping provides atomicity. Acceptable for this table size.

---

### 4. **handleNextTaskQuery - Type Cast**
**File**: `/workspace/delegate/src/services/handlers/queue-handler.ts:152-190`
**Severity**: INFORMATIONAL
**Type**: Type Safety

```typescript
const correlationId = (event as any).__correlationId;
if (correlationId && this.eventBus && 'respondError' in this.eventBus) {
  (this.eventBus as any).respondError(correlationId, result.error);
}
```

**Analysis**: Multiple `as any` casts suggest the event correlation pattern isn't well-typed.

**Recommendation**: Define proper types for correlation events in a future type-safety sprint. Not related to this branch's changes.

---

## Metrics Summary

### Changes Introduced by This Branch

| File | Lines Added | Lines Removed | Net Change |
|------|-------------|---------------|------------|
| dependency-repository.ts | +20 | -7 | +13 (interface) |
| task-repository.ts | +34 | -4 | +30 (interface) |
| dependency-handler.ts | +20 | -4 | +16 (config) |
| queue-handler.ts | +5 | -10 | -5 (simplify) |
| database.ts | +41 | 0 | +41 (migration) |
| **Total** | **+120** | **-25** | **+95** |

### Complexity Metrics

| Metric | Before | After | Delta |
|--------|--------|-------|-------|
| Type Casts (`as any`) | 8 | 0* | -8 |
| Explicit Row Types | 0 | 2 | +2 |
| Configurable Constants | 0 | 1 | +1 |
| Method Count (QueueHandler) | 10 | 9 | -1 |

*In modified code only. Pre-existing `as any` casts remain elsewhere.

---

## Your Changes

**Critical Issues**: 0
**High Issues**: 0  
**Medium Issues**: 0

## Code You Touched

**High Issues**: 0
**Medium Issues**: 1 (TaskRow field count - acceptable)

## Pre-existing

**Medium Issues**: 0
**Low/Info Issues**: 4

---

## Complexity Score: 9/10

**Justification**: This branch REDUCES complexity:
- Replaces `Record<string, any>` with explicit types (+type safety)
- Makes magic constant configurable (+testability)
- Simplifies `getQueueStats()` to `getQueueSize()` (+performance, -complexity)
- Documentation updates align with code reality

---

## Merge Recommendation

**[APPROVED]**

This branch improves code quality without introducing complexity issues:
- Type safety improvements are clean and complete
- Configuration changes follow existing patterns
- Performance optimization is straightforward
- Migration is correctly implemented

**No blocking issues. Safe to merge.**

---

## Appendix: Changed Files Reference

1. `/workspace/delegate/src/implementations/dependency-repository.ts`
   - Added `DependencyRow` interface (lines 19-26)
   - Changed 7 type casts from `Record<string, any>` to `DependencyRow`

2. `/workspace/delegate/src/implementations/task-repository.ts`
   - Added `TaskRow` interface (lines 17-43)
   - Changed 4 type casts from `Record<string, any>` to `TaskRow`
   - Added explicit type casts in `rowToTask()` (lines 240-241)

3. `/workspace/delegate/src/services/handlers/dependency-handler.ts`
   - Exported `DEFAULT_MAX_DEPENDENCY_CHAIN_DEPTH` constant (line 26)
   - Added `DependencyHandlerOptions` interface (lines 28-32)
   - Added `maxChainDepth` instance field (line 37)
   - Updated constructor signature (lines 48-49)
   - Updated factory method signature (lines 73-76)

4. `/workspace/delegate/src/services/handlers/queue-handler.ts`
   - Replaced `getQueueStats()` with `getQueueSize()` (lines 352-354)
   - Removed unused `tasks` array return

5. `/workspace/delegate/src/implementations/database.ts`
   - Added migration v2 for CHECK constraint (lines 274-314)

6. Documentation files (corrections only, no complexity impact)
