"""
Scans API blueprint.

Handles endpoints for triggering scans, listing scan history, and retrieving
scan results.
"""

import logging
from flask import Blueprint, current_app, jsonify, request
from sqlalchemy.exc import SQLAlchemyError

from web.auth.decorators import api_auth_required
from web.services.scan_service import ScanService
from web.utils.validators import validate_config_file
from web.utils.pagination import validate_page_params

bp = Blueprint('scans', __name__)
logger = logging.getLogger(__name__)


@bp.route('', methods=['GET'])
@api_auth_required
def list_scans():
    """
    List all scans with pagination.

    Query params:
        page: Page number (default: 1)
        per_page: Items per page (default: 20, max: 100)
        status: Filter by status (running, completed, failed)

    Returns:
        JSON response with scans list and pagination info
    """
    try:
        # Get and validate query parameters
        page = request.args.get('page', 1, type=int)
        per_page = request.args.get('per_page', 20, type=int)
        status_filter = request.args.get('status', None, type=str)

        # Validate pagination params
        page, per_page = validate_page_params(page, per_page)

        # Get scans from service
        scan_service = ScanService(current_app.db_session)
        paginated_result = scan_service.list_scans(
            page=page,
            per_page=per_page,
            status_filter=status_filter
        )

        logger.info(f"Listed scans: page={page}, per_page={per_page}, status={status_filter}, total={paginated_result.total}")

        return jsonify({
            'scans': paginated_result.items,
            'total': paginated_result.total,
            'page': paginated_result.page,
            'per_page': paginated_result.per_page,
            'total_pages': paginated_result.pages,
            'has_prev': paginated_result.has_prev,
            'has_next': paginated_result.has_next
        })

    except ValueError as e:
        logger.warning(f"Invalid request parameters: {str(e)}")
        return jsonify({
            'error': 'Invalid request',
            'message': str(e)
        }), 400
    except SQLAlchemyError as e:
        logger.error(f"Database error listing scans: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to retrieve scans'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error listing scans: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


@bp.route('/<int:scan_id>', methods=['GET'])
@api_auth_required
def get_scan(scan_id):
    """
    Get details for a specific scan.

    Args:
        scan_id: Scan ID

    Returns:
        JSON response with scan details
    """
    try:
        # Get scan from service
        scan_service = ScanService(current_app.db_session)
        scan = scan_service.get_scan(scan_id)

        if not scan:
            logger.warning(f"Scan not found: {scan_id}")
            return jsonify({
                'error': 'Not found',
                'message': f'Scan with ID {scan_id} not found'
            }), 404

        logger.info(f"Retrieved scan details: {scan_id}")
        return jsonify(scan)

    except SQLAlchemyError as e:
        logger.error(f"Database error retrieving scan {scan_id}: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to retrieve scan'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error retrieving scan {scan_id}: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


@bp.route('', methods=['POST'])
@api_auth_required
def trigger_scan():
    """
    Trigger a new scan.

    Request body:
        config_id: Database config ID (required)

    Returns:
        JSON response with scan_id and status
    """
    try:
        # Get request data
        data = request.get_json() or {}
        config_id = data.get('config_id')

        # Validate required fields
        if not config_id:
            logger.warning("Scan trigger request missing config_id")
            return jsonify({
                'error': 'Invalid request',
                'message': 'config_id is required'
            }), 400

        # Validate config_id is an integer
        try:
            config_id = int(config_id)
        except (TypeError, ValueError):
            logger.warning(f"Invalid config_id type: {config_id}")
            return jsonify({
                'error': 'Invalid request',
                'message': 'config_id must be an integer'
            }), 400

        # Trigger scan via service
        scan_service = ScanService(current_app.db_session)
        scan_id = scan_service.trigger_scan(
            config_id=config_id,
            triggered_by='api',
            scheduler=current_app.scheduler
        )

        logger.info(f"Scan {scan_id} triggered via API: config_id={config_id}")

        return jsonify({
            'scan_id': scan_id,
            'status': 'running',
            'message': 'Scan queued successfully'
        }), 201

    except ValueError as e:
        # Config validation error
        error_message = str(e)
        logger.warning(f"Invalid config: {error_message}")
        logger.warning(f"Request data: config_id='{config_id}'")
        return jsonify({
            'error': 'Invalid request',
            'message': error_message
        }), 400
    except SQLAlchemyError as e:
        logger.error(f"Database error triggering scan: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to create scan'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error triggering scan: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


@bp.route('/<int:scan_id>', methods=['DELETE'])
@api_auth_required
def delete_scan(scan_id):
    """
    Delete a scan and its associated files.

    Args:
        scan_id: Scan ID to delete

    Returns:
        JSON response with deletion status
    """
    try:
        # Delete scan via service
        scan_service = ScanService(current_app.db_session)
        scan_service.delete_scan(scan_id)

        logger.info(f"Scan {scan_id} deleted successfully")

        return jsonify({
            'scan_id': scan_id,
            'message': 'Scan deleted successfully'
        }), 200

    except ValueError as e:
        # Scan not found
        logger.warning(f"Scan deletion failed: {str(e)}")
        return jsonify({
            'error': 'Not found',
            'message': str(e)
        }), 404
    except SQLAlchemyError as e:
        logger.error(f"Database error deleting scan {scan_id}: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to delete scan'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error deleting scan {scan_id}: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


@bp.route('/<int:scan_id>/status', methods=['GET'])
@api_auth_required
def get_scan_status(scan_id):
    """
    Get current status of a running scan.

    Args:
        scan_id: Scan ID

    Returns:
        JSON response with scan status and progress
    """
    try:
        # Get scan status from service
        scan_service = ScanService(current_app.db_session)
        status = scan_service.get_scan_status(scan_id)

        if not status:
            logger.warning(f"Scan not found for status check: {scan_id}")
            return jsonify({
                'error': 'Not found',
                'message': f'Scan with ID {scan_id} not found'
            }), 404

        logger.debug(f"Retrieved status for scan {scan_id}: {status['status']}")
        return jsonify(status)

    except SQLAlchemyError as e:
        logger.error(f"Database error retrieving scan status {scan_id}: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to retrieve scan status'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error retrieving scan status {scan_id}: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


@bp.route('/<int:scan_id1>/compare/<int:scan_id2>', methods=['GET'])
@api_auth_required
def compare_scans(scan_id1, scan_id2):
    """
    Compare two scans and show differences.

    Compares ports, services, and certificates between two scans,
    highlighting added, removed, and changed items.

    Args:
        scan_id1: First (older) scan ID
        scan_id2: Second (newer) scan ID

    Returns:
        JSON response with comparison results including:
        - scan1, scan2: Metadata for both scans
        - ports: Added, removed, and unchanged ports
        - services: Added, removed, and changed services
        - certificates: Added, removed, and changed certificates
        - drift_score: Overall drift metric (0.0-1.0)
    """
    try:
        # Compare scans using service
        scan_service = ScanService(current_app.db_session)
        comparison = scan_service.compare_scans(scan_id1, scan_id2)

        if not comparison:
            logger.warning(f"Scan comparison failed: one or both scans not found ({scan_id1}, {scan_id2})")
            return jsonify({
                'error': 'Not found',
                'message': 'One or both scans not found'
            }), 404

        logger.info(f"Compared scans {scan_id1} and {scan_id2}: drift_score={comparison['drift_score']}")
        return jsonify(comparison), 200

    except SQLAlchemyError as e:
        logger.error(f"Database error comparing scans {scan_id1} and {scan_id2}: {str(e)}")
        return jsonify({
            'error': 'Database error',
            'message': 'Failed to compare scans'
        }), 500
    except Exception as e:
        logger.error(f"Unexpected error comparing scans {scan_id1} and {scan_id2}: {str(e)}", exc_info=True)
        return jsonify({
            'error': 'Internal server error',
            'message': 'An unexpected error occurred'
        }), 500


# Health check endpoint
@bp.route('/health', methods=['GET'])
def health_check():
    """
    Health check endpoint for monitoring.

    Returns:
        JSON response with API health status
    """
    return jsonify({
        'status': 'healthy',
        'api': 'scans',
        'version': '1.0.0-phase1'
    })