# FileHeatmap Integration Summary

## Overview
The FileHeatmap component is fully integrated into the FABRIC TUI application, providing real-time visualization of file modification patterns and collision detection.

## Integration Points

### 1. Component Instantiation
**Location:** `src/tui/app.ts:136-143`
```typescript
this.fileHeatmap = new FileHeatmap({
  parent: this.screen,
  top: 1,
  left: 0,
  width: '100%',
  bottom: 1,
});
this.fileHeatmap.getElement().hide();
```

### 2. Keyboard Shortcut
**Key:** `H` (uppercase)
**Location:** `src/tui/app.ts:270-272`
- Toggles between default view and heatmap view
- Pressing `H` again or `Escape` returns to default view

### 3. Data Aggregation
**Location:** `src/tui/app.ts:401-404, 673-679`

The heatmap aggregates file access counts from the event store:
```typescript
this.fileHeatmap.updateData(
  (opts) => this.store.getFileHeatmap(opts),
  () => this.store.getFileHeatmapStats()
);
```

**Store Methods:**
- `getFileHeatmap(options)` - Returns sorted file entries (src/store.ts:501-585)
- `getFileHeatmapStats()` - Returns aggregate statistics (src/store.ts:590-637)

### 4. Features
- **Real-time updates:** Heatmap updates automatically when new events are added
- **Multiple sort modes:**
  - Modifications (default)
  - Recent activity
  - Worker count
  - Collision priority
- **Filtering:**
  - Collisions only mode (`c` key)
  - Directory filtering
- **Heat levels:**
  - Cold (1-2 modifications)
  - Warm (3-5 modifications)
  - Hot (6-10 modifications)
  - Critical (11+ modifications)
- **Worker tracking:** Shows which workers are modifying each file
- **Collision detection:** Highlights files with concurrent modifications

### 5. View Management
**Location:** `src/tui/app.ts:388-409`

View mode state machine:
- `default` - Worker grid + Activity stream
- `heatmap` - Full-screen file heatmap
- `dag` - Dependency DAG view
- `replay` - Session replay
- `errors` - Error groups

### 6. Help Text
**Location:** `src/tui/app.ts:601-614`
```
Heatmap View:
  s       - Cycle sort mode
  c       - Toggle collisions only
  Esc     - Return to default view
```

## Test Coverage

### Component Tests
- **FileHeatmap.test.ts:** 51 tests covering UI component behavior
- **fileHeatmap.test.ts:** 20 tests covering heatmap logic
- **FileHeatmap.test.tsx:** 15 tests covering web frontend
- **app.test.ts:** 44 tests including heatmap integration

**Total:** 130 tests covering FileHeatmap functionality
**Status:** ✅ All tests passing

## Usage

1. Start FABRIC TUI: `npm start` or `npm run tui`
2. Press `H` to open the file heatmap view
3. Use `s` to cycle through sort modes:
   - Modifications (default)
   - Recent activity
   - Worker count
   - Collision priority
4. Press `c` to filter for files with collisions only
5. Use `j/k` or arrow keys to navigate files
6. Press `Esc` to return to the default view

## Technical Details

### Data Flow
```
LogEvents → Store.add() → FileModificationTracker
                              ↓
                    Store.getFileHeatmap()
                              ↓
                    FileHeatmap.updateData()
                              ↓
                      FileHeatmap.render()
```

### Performance
- File modifications tracked in-memory with `Map<string, FileModificationTracker>`
- Efficient O(1) lookups for file access patterns
- Configurable max entries limit (default: 50)
- Timestamps stored for interval calculations

### Collision Detection
The heatmap integrates with the collision detection system to highlight:
- **Active collisions** (⚠ red): Multiple workers modifying same file within 5s window
- **Potential collisions** (⚡ yellow): Multiple workers actively working on same file
- **Safe files** (no indicator): Single worker or no recent conflicts

## Related Files
- Component: `src/tui/components/FileHeatmap.ts`
- Integration: `src/tui/app.ts`
- Store logic: `src/store.ts`
- Tests: `src/tui/components/FileHeatmap.test.ts`, `src/tui/app.test.ts`
- Types: `src/types.ts` (FileHeatmapEntry, FileHeatmapStats, HeatmapOptions)

## Completion Status
✅ **COMPLETE** - FileHeatmap is fully integrated and functional
- Keyboard shortcut 'H' working
- Data aggregation from store working
- Real-time updates working
- All tests passing (943 total)
- Help documentation included