semblance-dev/backend/app/routes/tasks.py

"""
Task management routes for handling cancellable operations.
"""

from quart import Blueprint, jsonify, request
from app.services.task_manager import get_task_manager
from app.websocket_manager_async import get_async_websocket_manager
from app.auth.quart_jwt import jwt_required, get_jwt_identity
import logging

logger = logging.getLogger(__name__)

tasks_bp = Blueprint('tasks', __name__)


@tasks_bp.route('/<task_id>', methods=['GET'])
@jwt_required()
async def get_task_result(task_id: str):
    """
    Poll for task status and result.
    Returns 200 with {task_id, status, task_type, result?, error?} if found.
    Returns 404 if task not found (expired or never existed).
    """
    try:
        task_manager = get_task_manager()
        data = await task_manager.get_task_status_dict(task_id)
        if not data:
            return jsonify({'error': 'Task not found or expired', 'task_id': task_id}), 404
        return jsonify(data), 200
    except Exception as e:
        logger.error(f"Error fetching task result {task_id}: {str(e)}")
        return jsonify({'error': 'Internal server error', 'task_id': task_id}), 500


@tasks_bp.route('/<task_id>', methods=['DELETE'])
@jwt_required()
async def cancel_task(task_id: str):
    """
    Cancel a running task by its ID.
    
    Args:
        task_id: The unique identifier of the task to cancel
        
    Returns:
        JSON response indicating success or failure
    """
    try:
        task_manager = get_task_manager()
        
        # Get task info before cancellation for WebSocket notification
        task_info = await task_manager.get_task_info(task_id)
        
        # Attempt to cancel the task
        cancelled = await task_manager.cancel_task(task_id)
        
        if not cancelled:
            return jsonify({
                'error': 'Task not found or already completed',
                'task_id': task_id
            }), 404

        await task_manager.store_result(task_id, 'cancelled')

        # Send WebSocket notification about cancellation
        websocket_manager = get_async_websocket_manager()
        if task_info and task_info.user_id:
            await websocket_manager.emit_to_user(
                task_info.user_id,
                'task_cancelled',
                {
                    'task_id': task_id,
                    'task_type': task_info.task_type,
                    'message': f'{task_info.task_type.replace("_", " ").title()} cancelled successfully'
                }
            )
        
        logger.info(f"Successfully cancelled task {task_id}")
        
        return jsonify({
            'message': 'Task cancelled successfully',
            'task_id': task_id,
            'task_type': task_info.task_type if task_info else None
        }), 200
        
    except Exception as e:
        logger.error(f"Error cancelling task {task_id}: {str(e)}")
        return jsonify({
            'error': 'Internal server error while cancelling task',
            'task_id': task_id
        }), 500


@tasks_bp.route('/user/me', methods=['GET'])
@jwt_required()
async def get_user_tasks():
    """
    Get all active tasks for the authenticated user.

    Returns:
        JSON response with list of active tasks
    """
    try:
        user_id = get_jwt_identity()
        task_manager = get_task_manager()
        user_tasks = await task_manager.get_user_tasks(user_id)
        
        # Convert task info to JSON-serializable format
        tasks_data = []
        for task_id, task_info in user_tasks.items():
            tasks_data.append({
                'task_id': task_id,
                'task_type': task_info.task_type,
                'status': task_info.status,
                'created_at': task_info.created_at.isoformat(),
                'metadata': task_info.metadata
            })
        
        return jsonify({
            'tasks': tasks_data,
            'count': len(tasks_data)
        }), 200
        
    except Exception as e:
        logger.error(f"Error fetching tasks for user {user_id}: {str(e)}")
        return jsonify({
            'error': 'Internal server error while fetching user tasks'
        }), 500


@tasks_bp.route('/status', methods=['GET'])
async def get_task_status():
    """
    Get overall task manager status (for debugging/monitoring).
    
    Returns:
        JSON response with task manager statistics
    """
    try:
        task_manager = get_task_manager()
        active_count = await task_manager.get_active_task_count()
        
        return jsonify({
            'active_tasks': active_count,
            'status': 'operational'
        }), 200
        
    except Exception as e:
        logger.error(f"Error fetching task manager status: {str(e)}")
        return jsonify({
            'error': 'Internal server error while fetching status'
        }), 500