import os
import click
from flask import Flask, send_from_directory
from flask_cors import CORS
from flask_migrate import Migrate
from flask_socketio import SocketIO

from backend.models import db
from backend.config import config

# Initialize extensions
migrate = Migrate()
socketio = SocketIO(cors_allowed_origins="*", async_mode='eventlet')


def create_app(config_name=None):
    """Flask application factory"""
    if config_name is None:
        config_name = os.environ.get('FLASK_ENV', 'development')

    app = Flask(__name__,
                static_folder=os.path.join(os.path.dirname(__file__), 'static'),
                static_url_path='/static')

    # Load configuration
    app.config.from_object(config[config_name])

    # Configure session for OAuth state management
    app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'  # Allow cross-site on redirects
    app.config['SESSION_COOKIE_HTTPONLY'] = True

    # Ensure required directories exist
    os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)
    os.makedirs(app.config['AUDIO_FOLDER'], exist_ok=True)

    # Ensure database instance directory exists
    db_path = app.config['SQLALCHEMY_DATABASE_URI'].replace('sqlite:///', '')
    if db_path and db_path != ':memory:':
        os.makedirs(os.path.dirname(db_path), exist_ok=True)

    # Initialize extensions
    db.init_app(app)
    migrate.init_app(app, db)
    socketio.init_app(app)
    CORS(app,
         resources={r"/api/*": {"origins": app.config['CORS_ORIGINS']}},
         supports_credentials=True)

    # Initialize OAuth/OIDC
    from backend.auth import init_oauth
    init_oauth(app)

    # Register blueprints
    from backend.routes import questions, games, teams, admin, categories, download_jobs, auth, export_import
    app.register_blueprint(auth.bp)
    app.register_blueprint(questions.bp)
    app.register_blueprint(games.bp)
    app.register_blueprint(teams.bp)
    app.register_blueprint(admin.bp)
    app.register_blueprint(categories.bp)
    app.register_blueprint(download_jobs.bp)
    app.register_blueprint(export_import.bp)

    # Register socket events
    from backend.sockets import events

    # Serve React frontend in production
    @app.route('/', defaults={'path': ''})
    @app.route('/<path:path>')
    def serve_frontend(path):
        """Serve React frontend"""
        if path and os.path.exists(os.path.join(app.static_folder, path)):
            return send_from_directory(app.static_folder, path)
        elif path.startswith('api/'):
            # API routes should 404 if not found
            return {'error': 'Not found'}, 404
        else:
            # Serve index.html for all other routes (React Router)
            index_path = os.path.join(app.static_folder, 'index.html')
            if os.path.exists(index_path):
                return send_from_directory(app.static_folder, 'index.html')
            else:
                return {'message': 'Trivia Game API', 'status': 'running'}, 200

    # Health check endpoint
    @app.route('/api/health')
    def health_check():
        """Health check endpoint"""
        return {'status': 'ok', 'message': 'Trivia Game API is running'}, 200

    @app.cli.command('transfer-questions')
    @click.argument('user_id', type=int)
    def transfer_questions(user_id):
        """Transfer ownership of ALL questions to the specified user.

        USER_ID is the database ID of the target user.
        """
        from backend.models import User, Question

        user = User.query.get(user_id)
        if not user:
            click.echo(f"Error: No user found with id {user_id}")
            click.echo("Available users:")
            for u in User.query.all():
                click.echo(f"  - id={u.id}, name={u.name or u.preferred_username}")
            raise SystemExit(1)

        display_name = user.name or user.preferred_username

        count = Question.query.count()
        if count == 0:
            click.echo("No questions found in the database.")
            return

        click.echo(f"This will transfer ownership of {count} question(s) to '{display_name}' (id={user.id}).")
        if not click.confirm("Proceed?"):
            click.echo("Aborted.")
            return

        Question.query.update({Question.created_by: user.id})
        db.session.commit()
        click.echo(f"Successfully transferred {count} question(s) to '{display_name}'.")

    return app