"""Flask application factory."""

import os
import logging
from flask import Flask, send_from_directory

from .config import config
from .extensions import db, migrate, jwt, cors, ma, init_extensions
from .plugins import plugin_manager


def create_app(config_name: str = None) -> Flask:
    """
    Application factory.

    Args:
        config_name: Configuration name ('development', 'production', 'testing')

    Returns:
        Configured Flask application
    """
    if config_name is None:
        config_name = os.environ.get('FLASK_ENV', 'development')

    app = Flask(__name__, instance_relative_config=True)

    # Load configuration
    app.config.from_object(config.get(config_name, config['default']))

    # Load instance config if exists
    app.config.from_pyfile('config.py', silent=True)

    # Ensure instance folder exists
    os.makedirs(app.instance_path, exist_ok=True)

    # Configure logging
    configure_logging(app)

    # Initialize extensions
    init_extensions(app)

    # Initialize plugin manager
    with app.app_context():
        plugin_manager.init_app(app, db)

    # Register core blueprints
    register_blueprints(app)

    # Register CLI commands
    register_cli_commands(app)

    # Register error handlers
    register_error_handlers(app)

    # Serve Vue frontend
    register_frontend_routes(app)

    # JWT user loader (identity is a string in JWT, convert to int for DB lookup)
    @jwt.user_lookup_loader
    def user_lookup_callback(_jwt_header, jwt_data):
        from .core.models import User
        identity = jwt_data["sub"]
        return User.query.get(int(identity))

    return app


def register_blueprints(app: Flask):
    """Register core API blueprints."""
    from .core.api import (
        auth_bp,
        assets_bp,
        machines_bp,
        machinetypes_bp,
        pctypes_bp,
        statuses_bp,
        vendors_bp,
        models_bp,
        businessunits_bp,
        locations_bp,
        operatingsystems_bp,
        dashboard_bp,
        applications_bp,
        knowledgebase_bp,
        search_bp,
        reports_bp,
        collector_bp,
        employees_bp,
        slides_bp,
        settings_bp,
        auditlogs_bp,
        users_bp,
    )

    api_prefix = '/api'

    app.register_blueprint(auth_bp, url_prefix=f'{api_prefix}/auth')
    app.register_blueprint(assets_bp, url_prefix=f'{api_prefix}/assets')
    app.register_blueprint(machines_bp, url_prefix=f'{api_prefix}/machines')
    app.register_blueprint(machinetypes_bp, url_prefix=f'{api_prefix}/machinetypes')
    app.register_blueprint(pctypes_bp, url_prefix=f'{api_prefix}/pctypes')
    app.register_blueprint(statuses_bp, url_prefix=f'{api_prefix}/statuses')
    app.register_blueprint(vendors_bp, url_prefix=f'{api_prefix}/vendors')
    app.register_blueprint(models_bp, url_prefix=f'{api_prefix}/models')
    app.register_blueprint(businessunits_bp, url_prefix=f'{api_prefix}/businessunits')
    app.register_blueprint(locations_bp, url_prefix=f'{api_prefix}/locations')
    app.register_blueprint(operatingsystems_bp, url_prefix=f'{api_prefix}/operatingsystems')
    app.register_blueprint(dashboard_bp, url_prefix=f'{api_prefix}/dashboard')
    app.register_blueprint(applications_bp, url_prefix=f'{api_prefix}/applications')
    app.register_blueprint(knowledgebase_bp, url_prefix=f'{api_prefix}/knowledgebase')
    app.register_blueprint(search_bp, url_prefix=f'{api_prefix}/search')
    app.register_blueprint(reports_bp, url_prefix=f'{api_prefix}/reports')
    app.register_blueprint(collector_bp, url_prefix=f'{api_prefix}/collector')
    app.register_blueprint(employees_bp, url_prefix=f'{api_prefix}/employees')
    app.register_blueprint(slides_bp, url_prefix=f'{api_prefix}/slides')
    app.register_blueprint(settings_bp, url_prefix=f'{api_prefix}/settings')
    app.register_blueprint(auditlogs_bp, url_prefix=f'{api_prefix}/auditlogs')
    app.register_blueprint(users_bp, url_prefix=f'{api_prefix}/users')


def register_cli_commands(app: Flask):
    """Register Flask CLI commands."""
    from .plugins.cli import plugin_cli
    from .cli import db_cli, seed_cli

    app.cli.add_command(plugin_cli)
    app.cli.add_command(db_cli)
    app.cli.add_command(seed_cli)


def register_error_handlers(app: Flask):
    """Register error handlers."""
    from .utils.responses import error_response, ErrorCodes
    from .exceptions import ShopDBException

    @app.errorhandler(ShopDBException)
    def handle_shopdb_exception(error):
        http_codes = {
            'NOT_FOUND': 404,
            'UNAUTHORIZED': 401,
            'FORBIDDEN': 403,
            'CONFLICT': 409,
            'VALIDATION_ERROR': 400,
        }
        http_code = http_codes.get(error.code, 400)
        return error_response(
            error.code,
            error.message,
            details=error.details,
            http_code=http_code
        )

    @app.errorhandler(404)
    def not_found_error(error):
        return error_response(
            ErrorCodes.NOT_FOUND,
            'Resource not found',
            http_code=404
        )

    @app.errorhandler(500)
    def internal_error(error):
        return error_response(
            ErrorCodes.INTERNAL_ERROR,
            'An internal error occurred',
            http_code=500
        )

    @app.errorhandler(401)
    def unauthorized_error(error):
        return error_response(
            ErrorCodes.UNAUTHORIZED,
            'Authentication required',
            http_code=401
        )


def register_frontend_routes(app: Flask):
    """Serve Vue frontend static files."""
    frontend_dist = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'frontend', 'dist')

    @app.route('/', defaults={'path': ''})
    @app.route('/<path:path>')
    def serve_frontend(path):
        # Don't serve API routes as frontend
        if path.startswith('api/'):
            from .utils.responses import error_response, ErrorCodes
            return error_response(ErrorCodes.NOT_FOUND, 'API endpoint not found', http_code=404)

        # Serve static assets
        if path and os.path.exists(os.path.join(frontend_dist, path)):
            return send_from_directory(frontend_dist, path)

        # Serve index.html for SPA routing
        return send_from_directory(frontend_dist, 'index.html')


def configure_logging(app: Flask):
    """Configure application logging."""
    log_level = app.config.get('LOG_LEVEL', 'INFO')

    logging.basicConfig(
        level=getattr(logging, log_level),
        format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )