platform/doc/queue_gap_analysis.md

# Queue Package Gap Analysis

## Overview

This document analyzes the gaps between our Queue package's actual implementation and Laravel's queue functionality, identifying areas that need implementation or documentation updates.

> **Related Documentation**
> - See [Queue Package Specification](queue_package_specification.md) for current implementation
> - See [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md) for overall status
> - See [Foundation Integration Guide](foundation_integration_guide.md) for integration patterns
> - See [Testing Guide](testing_guide.md) for testing approaches
> - See [Getting Started Guide](getting_started.md) for development setup
> - See [Events Package Specification](events_package_specification.md) for event integration
> - See [Bus Package Specification](bus_package_specification.md) for command bus integration

## Implementation Gaps

### 1. Missing Laravel Features
```dart
// Documented but not implemented:

// 1. Job Middleware
class JobMiddleware {
  // Need to implement:
  Future<void> handle(Job job, Function next);
  Future<void> withoutOverlapping(Job job, Function next);
  Future<void> rateLimit(Job job, Function next, int maxAttempts);
  Future<void> throttle(Job job, Function next, Duration duration);
}

// 2. Job Events
class JobEvents {
  // Need to implement:
  void beforeJob(Job job);
  void afterJob(Job job);
  void failingJob(Job job, Exception exception);
  void failedJob(Job job, Exception exception);
  void retryingJob(Job job);
  void retriedJob(Job job);
}

// 3. Job Chaining
class JobChain {
  // Need to implement:
  void chain(List<Job> jobs);
  void onConnection(String connection);
  void onQueue(String queue);
  void catch(Function(Exception) handler);
  void finally(Function handler);
}
```

### 2. Missing Queue Features
```dart
// Need to implement:

// 1. Queue Monitoring
class QueueMonitor {
  // Need to implement:
  Future<Map<String, int>> queueSizes();
  Future<List<Map<String, dynamic>>> failedJobs();
  Future<void> retryFailedJob(String id);
  Future<void> forgetFailedJob(String id);
  Future<void> pruneFailedJobs([Duration? older]);
}

// 2. Queue Rate Limiting
class QueueRateLimiter {
  // Need to implement:
  Future<bool> tooManyAttempts(String key, int maxAttempts);
  Future<void> hit(String key, Duration decay);
  Future<void> clear(String key);
  Future<int> attempts(String key);
  Future<int> remaining(String key, int maxAttempts);
}

// 3. Queue Batching
class QueueBatch {
  // Need to implement:
  Future<void> then(Function handler);
  Future<void> catch(Function(Exception) handler);
  Future<void> finally(Function handler);
  Future<void> allowFailures();
  Future<void> onConnection(String connection);
  Future<void> onQueue(String queue);
}
```

### 3. Missing Worker Features
```dart
// Need to implement:

// 1. Worker Management
class WorkerManager {
  // Need to implement:
  Future<void> scale(int processes);
  Future<void> pause();
  Future<void> resume();
  Future<void> restart();
  Future<List<WorkerStatus>> status();
}

// 2. Worker Events
class WorkerEvents {
  // Need to implement:
  void workerStarting();
  void workerStopping();
  void workerStopped();
  void queueEmpty(String queue);
  void looping();
}

// 3. Worker Options
class WorkerOptions {
  // Need to implement:
  Duration sleep;
  Duration timeout;
  int maxTries;
  int maxJobs;
  bool force;
  bool stopWhenEmpty;
  bool rest;
}
```

## Documentation Gaps

### 1. Missing API Documentation
```dart
// Need to document:

/// Handles job middleware.
/// 
/// Example:
/// ```dart
/// class RateLimitedJob extends Job with JobMiddleware {
///   @override
///   Future<void> middleware(Function next) async {
///     return await rateLimit(5, Duration(minutes: 1), next);
///   }
/// }
/// ```
Future<void> middleware(Function next);

/// Handles job events.
///
/// Example:
/// ```dart
/// queue.beforeJob((job) {
///   print('Processing ${job.id}');
/// });
/// ```
void beforeJob(Function(Job) callback);
```

### 2. Missing Integration Examples
```dart
// Need examples for:

// 1. Job Chaining
var chain = queue.chain([
  ProcessPodcast(podcast),
  OptimizeAudio(podcast),
  NotifySubscribers(podcast)
])
.onQueue('podcasts')
.catch((e) => handleError(e))
.finally(() => cleanup());

// 2. Queue Monitoring
var monitor = QueueMonitor(queue);
var sizes = await monitor.queueSizes();
print('Default queue size: ${sizes["default"]}');

// 3. Worker Management
var manager = WorkerManager(queue);
await manager.scale(4); // Scale to 4 processes
var status = await manager.status();
print('Active workers: ${status.length}');
```

### 3. Missing Test Coverage
```dart
// Need tests for:

void main() {
  group('Job Middleware', () {
    test('applies rate limiting', () async {
      var job = RateLimitedJob();
      var limiter = MockRateLimiter();
      
      await job.handle();
      
      verify(() => limiter.tooManyAttempts(any, any)).called(1);
    });
  });
  
  group('Queue Monitoring', () {
    test('monitors queue sizes', () async {
      var monitor = QueueMonitor(queue);
      var sizes = await monitor.queueSizes();
      
      expect(sizes, containsPair('default', greaterThan(0)));
    });
  });
}
```

## Implementation Priority

1. **High Priority**
   - Job middleware (Laravel compatibility)
   - Job events (Laravel compatibility)
   - Queue monitoring

2. **Medium Priority**
   - Job chaining
   - Queue rate limiting
   - Worker management

3. **Low Priority**
   - Additional worker features
   - Additional monitoring features
   - Performance optimizations

## Next Steps

1. **Implementation Tasks**
   - Add job middleware
   - Add job events
   - Add queue monitoring
   - Add worker management

2. **Documentation Tasks**
   - Document job middleware
   - Document job events
   - Document monitoring
   - Add integration examples

3. **Testing Tasks**
   - Add middleware tests
   - Add event tests
   - Add monitoring tests
   - Add worker tests

## Development Guidelines

### 1. Getting Started
Before implementing queue features:
1. Review [Getting Started Guide](getting_started.md)
2. Check [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md)
3. Follow [Testing Guide](testing_guide.md)
4. Use [Foundation Integration Guide](foundation_integration_guide.md)
5. Review [Queue Package Specification](queue_package_specification.md)
6. Review [Events Package Specification](events_package_specification.md)
7. Review [Bus Package Specification](bus_package_specification.md)

### 2. Implementation Process
For each queue feature:
1. Write tests following [Testing Guide](testing_guide.md)
2. Implement following Laravel patterns
3. Document following [Getting Started Guide](getting_started.md#documentation)
4. Integrate following [Foundation Integration Guide](foundation_integration_guide.md)

### 3. Quality Requirements
All implementations must:
1. Pass all tests (see [Testing Guide](testing_guide.md))
2. Meet Laravel compatibility requirements
3. Follow integration patterns (see [Foundation Integration Guide](foundation_integration_guide.md))
4. Match specifications in [Queue Package Specification](queue_package_specification.md)

### 4. Integration Considerations
When implementing queue features:
1. Follow patterns in [Foundation Integration Guide](foundation_integration_guide.md)
2. Ensure Laravel compatibility per [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md)
3. Use testing approaches from [Testing Guide](testing_guide.md)
4. Follow development setup in [Getting Started Guide](getting_started.md)

### 5. Performance Guidelines
Queue system must:
1. Handle high job throughput
2. Process chains efficiently
3. Support concurrent workers
4. Scale horizontally
5. Meet performance targets in [Laravel Compatibility Roadmap](laravel_compatibility_roadmap.md#performance-benchmarks)

### 6. Testing Requirements
Queue tests must:
1. Cover all queue operations
2. Test middleware behavior
3. Verify event handling
4. Check worker management
5. Follow patterns in [Testing Guide](testing_guide.md)

### 7. Documentation Requirements
Queue documentation must:
1. Explain queue patterns
2. Show middleware examples
3. Cover error handling
4. Include performance tips
5. Follow standards in [Getting Started Guide](getting_started.md#documentation)