"""
Task Management API endpoints

Provides endpoints for:
- GET /api/tasks - Get paginated list of tasks with status filtering
- POST /api/tasks/create - Create a new scan task
- GET /api/tasks/detail - Get task details
- POST /api/tasks/delete - Delete a task
- GET /api/tasks/logs - Get task logs with pagination

Requirements: 3.1, 3.4
"""
import os
from flask import jsonify, request, current_app
from werkzeug.utils import secure_filename

from app import db
from app.api import api_bp
from app.models import Task, TaskLog, AWSCredential, UserCredential
from app.services import login_required, admin_required, get_current_user_from_context, check_credential_access
from app.errors import ValidationError, NotFoundError, AuthorizationError


ALLOWED_IMAGE_EXTENSIONS = {'png', 'jpg', 'jpeg', 'gif', 'bmp'}


def allowed_file(filename: str) -> bool:
    """Check if file extension is allowed for network diagram"""
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_IMAGE_EXTENSIONS


@api_bp.route('/tasks', methods=['GET'])
@login_required
def get_tasks():
    """
    Get paginated list of tasks with optional status filtering.
    
    Query Parameters:
        page: Page number (default: 1)
        page_size: Items per page (default: 20, max: 100)
        status: Optional filter by status (pending, running, completed, failed)
    
    Returns:
        JSON with 'data' array and 'pagination' object
    """
    current_user = get_current_user_from_context()
    
    # Get pagination parameters
    page = request.args.get('page', 1, type=int)
    # Support both pageSize (frontend) and page_size (backend convention)
    page_size = request.args.get('pageSize', type=int) or request.args.get('page_size', type=int) or 20
    page_size = min(page_size, 100)
    status = request.args.get('status', type=str)
    
    # Validate pagination
    if page < 1:
        page = 1
    if page_size < 1:
        page_size = 20
    
    # Build query based on user role
    if current_user.role in ['admin', 'power_user']:
        query = Task.query
    else:
        # Regular users can only see their own tasks
        query = Task.query.filter_by(created_by=current_user.id)
    
    # Apply status filter if provided
    if status and status in ['pending', 'running', 'completed', 'failed']:
        query = query.filter_by(status=status)
    
    # Order by created_at descending
    query = query.order_by(Task.created_at.desc())
    
    # Get total count
    total = query.count()
    total_pages = (total + page_size - 1) // page_size if total > 0 else 1
    
    # Apply pagination
    tasks = query.offset((page - 1) * page_size).limit(page_size).all()
    
    return jsonify({
        'data': [task.to_dict() for task in tasks],
        'pagination': {
            'page': page,
            'page_size': page_size,
            'total': total,
            'total_pages': total_pages
        }
    }), 200


@api_bp.route('/tasks/create', methods=['POST'])
@login_required
def create_task():
    """
    Create a new scan task.
    
    Request Body (JSON or multipart/form-data):
        name: Task name (required)
        credential_ids: List of credential IDs to use (required)
        regions: List of AWS regions to scan (required)
        project_metadata: Project metadata object (required)
            - clientName: Client name (required)
            - projectName: Project name (required)
            - bdManager: BD Manager name (optional)
            - bdManagerEmail: BD Manager email (optional)
            - solutionsArchitect: Solutions Architect name (optional)
            - solutionsArchitectEmail: Solutions Architect email (optional)
            - cloudEngineer: Cloud Engineer name (optional)
            - cloudEngineerEmail: Cloud Engineer email (optional)
        network_diagram: Network diagram image file (optional, multipart only)
    
    Returns:
        JSON with created task details and task_id
    """
    current_user = get_current_user_from_context()
    
    # Handle both JSON and multipart/form-data
    if request.content_type and 'multipart/form-data' in request.content_type:
        data = request.form.to_dict()
        # Parse JSON fields from form data
        import json
        if 'credential_ids' in data:
            data['credential_ids'] = json.loads(data['credential_ids'])
        if 'regions' in data:
            data['regions'] = json.loads(data['regions'])
        if 'project_metadata' in data:
            data['project_metadata'] = json.loads(data['project_metadata'])
        network_diagram = request.files.get('network_diagram')
    else:
        data = request.get_json() or {}
        network_diagram = None
    
    # Validate required fields
    if not data.get('name'):
        raise ValidationError(
            message="Task name is required",
            details={"missing_fields": ["name"]}
        )
    
    credential_ids = data.get('credential_ids', [])
    if not credential_ids or not isinstance(credential_ids, list) or len(credential_ids) == 0:
        raise ValidationError(
            message="At least one credential must be selected",
            details={"missing_fields": ["credential_ids"]}
        )
    
    regions = data.get('regions', [])
    if not regions or not isinstance(regions, list) or len(regions) == 0:
        raise ValidationError(
            message="At least one region must be selected",
            details={"missing_fields": ["regions"]}
        )
    
    project_metadata = data.get('project_metadata', {})
    if not isinstance(project_metadata, dict):
        raise ValidationError(
            message="Project metadata must be an object",
            details={"field": "project_metadata", "reason": "invalid_type"}
        )
    
    # Validate required project metadata fields
    required_metadata = ['clientName', 'projectName']
    missing_metadata = [field for field in required_metadata if not project_metadata.get(field)]
    if missing_metadata:
        raise ValidationError(
            message="Missing required project metadata fields",
            details={"missing_fields": missing_metadata}
        )
    
    # Validate credential access for regular users
    for cred_id in credential_ids:
        if not check_credential_access(current_user, cred_id):
            raise AuthorizationError(
                message=f"Access denied to credential {cred_id}",
                details={"credential_id": cred_id, "reason": "not_assigned"}
            )
        
        # Verify credential exists and is active
        credential = db.session.get(AWSCredential, cred_id)
        if not credential:
            raise NotFoundError(
                message=f"Credential {cred_id} not found",
                details={"credential_id": cred_id}
            )
        if not credential.is_active:
            raise ValidationError(
                message=f"Credential {cred_id} is not active",
                details={"credential_id": cred_id, "reason": "inactive"}
            )
    
    # Handle network diagram upload
    network_diagram_path = None
    if network_diagram and network_diagram.filename:
        if not allowed_file(network_diagram.filename):
            raise ValidationError(
                message="Invalid file type for network diagram. Allowed: png, jpg, jpeg, gif, bmp",
                details={"field": "network_diagram", "reason": "invalid_file_type"}
            )
        
        # Save the file
        uploads_folder = current_app.config.get('UPLOAD_FOLDER', 'uploads')
        os.makedirs(uploads_folder, exist_ok=True)
        
        filename = secure_filename(network_diagram.filename)
        # Add timestamp to avoid conflicts
        import time
        filename = f"{int(time.time())}_{filename}"
        network_diagram_path = os.path.join(uploads_folder, filename)
        network_diagram.save(network_diagram_path)
        
        # Store path in project metadata
        project_metadata['network_diagram_path'] = network_diagram_path
    
    # Create task
    task = Task(
        name=data['name'].strip(),
        status='pending',
        progress=0,
        created_by=current_user.id
    )
    task.credential_ids = credential_ids
    task.regions = regions
    task.project_metadata = project_metadata
    
    db.session.add(task)
    db.session.commit()
    
    # Dispatch to Celery
    celery_task = None
    use_mock = False
    
    try:
        # 尝试使用真实的Celery (延迟导入)
        print("🔍 尝试导入Celery任务模块...")
        
        # 先测试Redis连接
        import redis
        r = redis.Redis(host='localhost', port=6379, db=0)
        r.ping()
        print("✅ Redis连接测试通过")
        
        # 导入并初始化Celery应用
        from app.celery_app import celery_app, init_celery
        
        # 确保Celery使用正确的broker配置
        init_celery(current_app._get_current_object())
        print(f"✅ Celery broker配置: {celery_app.conf.broker_url}")
        
        # 导入Celery任务
        from app.tasks.scan_tasks import scan_aws_resources
        print("✅ Celery任务模块导入成功")
        
        # 提交任务
        print("🔍 提交任务到Celery队列...")
        celery_task = scan_aws_resources.delay(
            task_id=task.id,
            credential_ids=credential_ids,
            regions=regions,
            project_metadata=project_metadata
        )
        print(f"✅ 任务已提交到Celery队列: {celery_task.id}")
        
    except Exception as e:
        # 详细的错误信息
        error_str = str(e)
        error_type = type(e).__name__
        print(f"❌ Celery任务提交失败:")
        print(f"   错误类型: {error_type}")
        print(f"   错误信息: {error_str}")
        
        use_mock = True
    
    # 如果Celery失败，使用Mock模式
    if use_mock:
        try:
            print("🔄 切换到Mock模式")
            from app.tasks.mock_tasks import scan_aws_resources
            celery_task = scan_aws_resources.delay(
                task_id=task.id,
                credential_ids=credential_ids,
                regions=regions,
                project_metadata=project_metadata
            )
            print(f"🔄 任务已提交到Mock队列: {celery_task.id}")
        except Exception as e:
            print(f"❌ Mock模式也失败: {e}")
            raise ValidationError(
                message="Failed to submit task to both Celery and Mock mode",
                details={"celery_error": str(e)}
            )
    
    # Store Celery task ID
    task.celery_task_id = celery_task.id
    db.session.commit()
    
    return jsonify({
        'message': 'Task created successfully',
        'task': task.to_dict(),
        'celery_task_id': celery_task.id
    }), 201


@api_bp.route('/tasks/detail', methods=['GET'])
@login_required
def get_task_detail():
    """
    Get task details including current status and progress.
    
    Query Parameters:
        id: Task ID (required)
    
    Returns:
        JSON with task details
    """
    current_user = get_current_user_from_context()
    task_id = request.args.get('id', type=int)
    
    if not task_id:
        raise ValidationError(
            message="Task ID is required",
            details={"missing_fields": ["id"]}
        )
    
    task = db.session.get(Task, task_id)
    if not task:
        raise NotFoundError(
            message="Task not found",
            details={"task_id": task_id}
        )
    
    # Check access for regular users
    if current_user.role == 'user' and task.created_by != current_user.id:
        raise AuthorizationError(
            message="Access denied",
            details={"reason": "not_owner"}
        )
    
    # Get task details with additional info
    task_dict = task.to_dict()
    
    # Add report info if available
    if task.report:
        task_dict['report'] = task.report.to_dict()
    
    # Add error count
    error_count = TaskLog.query.filter_by(task_id=task_id, level='error').count()
    task_dict['error_count'] = error_count
    
    # Get Celery task status if running
    if task.status == 'running' and task.celery_task_id:
        from celery.result import AsyncResult
        from app.celery_app import celery_app
        
        result = AsyncResult(task.celery_task_id, app=celery_app)
        if result.state == 'PROGRESS':
            task_dict['celery_progress'] = result.info
    
    return jsonify(task_dict), 200


@api_bp.route('/tasks/delete', methods=['POST'])
@login_required
def delete_task():
    """
    Delete a task and its associated logs and report.
    
    Request Body:
        id: Task ID (required)
    
    Returns:
        JSON with success message
    """
    current_user = get_current_user_from_context()
    data = request.get_json() or {}
    task_id = data.get('id')
    
    if not task_id:
        raise ValidationError(
            message="Task ID is required",
            details={"missing_fields": ["id"]}
        )
    
    task = db.session.get(Task, task_id)
    if not task:
        raise NotFoundError(
            message="Task not found",
            details={"task_id": task_id}
        )
    
    # Check access - only admin or task owner can delete
    if current_user.role != 'admin' and task.created_by != current_user.id:
        raise AuthorizationError(
            message="Access denied",
            details={"reason": "not_owner_or_admin"}
        )
    
    # Cannot delete running tasks
    if task.status == 'running':
        raise ValidationError(
            message="Cannot delete a running task",
            details={"task_id": task_id, "status": task.status}
        )
    
    # Delete associated report file if exists
    if task.report and task.report.file_path:
        try:
            if os.path.exists(task.report.file_path):
                os.remove(task.report.file_path)
        except OSError:
            pass  # File may already be deleted
    
    # Delete task (cascade will handle logs and report)
    db.session.delete(task)
    db.session.commit()
    
    return jsonify({
        'message': 'Task deleted successfully'
    }), 200


@api_bp.route('/tasks/logs', methods=['GET'])
@login_required
def get_task_logs():
    """
    Get paginated task logs.
    
    Query Parameters:
        id: Task ID (required)
        page: Page number (default: 1)
        page_size: Items per page (default: 20, max: 100)
        level: Optional filter by log level (info, warning, error)
    
    Returns:
        JSON with 'data' array and 'pagination' object
    
    Requirements:
        - 8.3: Display error logs associated with task
    """
    current_user = get_current_user_from_context()
    task_id = request.args.get('id', type=int)
    
    if not task_id:
        raise ValidationError(
            message="Task ID is required",
            details={"missing_fields": ["id"]}
        )
    
    task = db.session.get(Task, task_id)
    if not task:
        raise NotFoundError(
            message="Task not found",
            details={"task_id": task_id}
        )
    
    # Check access for regular users
    if current_user.role == 'user' and task.created_by != current_user.id:
        raise AuthorizationError(
            message="Access denied",
            details={"reason": "not_owner"}
        )
    
    # Get pagination parameters
    page = request.args.get('page', 1, type=int)
    # Support both pageSize (frontend) and page_size (backend convention)
    page_size = request.args.get('pageSize', type=int) or request.args.get('page_size', type=int) or 20
    page_size = min(page_size, 100)
    level = request.args.get('level', type=str)
    
    # Validate pagination
    if page < 1:
        page = 1
    if page_size < 1:
        page_size = 20
    
    # Build query
    query = TaskLog.query.filter_by(task_id=task_id)
    
    # Apply level filter if provided
    if level and level in ['info', 'warning', 'error']:
        query = query.filter_by(level=level)
    
    # Order by created_at descending
    query = query.order_by(TaskLog.created_at.desc())
    
    # Get total count
    total = query.count()
    total_pages = (total + page_size - 1) // page_size if total > 0 else 1
    
    # Apply pagination
    logs = query.offset((page - 1) * page_size).limit(page_size).all()
    
    return jsonify({
        'data': [log.to_dict() for log in logs],
        'pagination': {
            'page': page,
            'page_size': page_size,
            'total': total,
            'total_pages': total_pages
        }
    }), 200


@api_bp.route('/tasks/errors', methods=['GET'])
@login_required
def get_task_errors():
    """
    Get error logs for a specific task.
    
    This is a convenience endpoint that returns only error-level logs
    with full details including stack traces.
    
    Query Parameters:
        id: Task ID (required)
        page: Page number (default: 1)
        page_size: Items per page (default: 20, max: 100)
    
    Returns:
        JSON with 'data' array containing error logs and 'pagination' object
    
    Requirements:
        - 8.2: Record error details in task record
        - 8.3: Display error logs associated with task
    """
    current_user = get_current_user_from_context()
    task_id = request.args.get('id', type=int)
    
    if not task_id:
        raise ValidationError(
            message="Task ID is required",
            details={"missing_fields": ["id"]}
        )
    
    task = db.session.get(Task, task_id)
    if not task:
        raise NotFoundError(
            message="Task not found",
            details={"task_id": task_id}
        )
    
    # Check access for regular users
    if current_user.role == 'user' and task.created_by != current_user.id:
        raise AuthorizationError(
            message="Access denied",
            details={"reason": "not_owner"}
        )
    
    # Get pagination parameters
    page = request.args.get('page', 1, type=int)
    # Support both pageSize (frontend) and page_size (backend convention)
    page_size = request.args.get('pageSize', type=int) or request.args.get('page_size', type=int) or 20
    page_size = min(page_size, 100)
    
    # Validate pagination
    if page < 1:
        page = 1
    if page_size < 1:
        page_size = 20
    
    # Build query for error logs only
    query = TaskLog.query.filter_by(task_id=task_id, level='error')
    
    # Order by created_at descending
    query = query.order_by(TaskLog.created_at.desc())
    
    # Get total count
    total = query.count()
    total_pages = (total + page_size - 1) // page_size if total > 0 else 1
    
    # Apply pagination
    logs = query.offset((page - 1) * page_size).limit(page_size).all()
    
    # Build response with full error details
    error_data = []
    for log in logs:
        log_dict = log.to_dict()
        # Ensure details are included for error analysis
        error_data.append(log_dict)
    
    return jsonify({
        'data': error_data,
        'pagination': {
            'page': page,
            'page_size': page_size,
            'total': total,
            'total_pages': total_pages
        },
        'summary': {
            'total_errors': total,
            'task_status': task.status
        }
    }), 200