"""
DigiServer v2 - Application Factory
Modern Flask application with blueprint architecture
"""
import os
from flask import Flask, render_template
from dotenv import load_dotenv

from app.config import DevelopmentConfig, ProductionConfig, TestingConfig
from app.extensions import db, bcrypt, login_manager, migrate, cache

# Load environment variables
load_dotenv()


def create_app(config_name=None):
    """
    Application factory pattern
    
    Args:
        config_name: Configuration environment (development, production, testing)
    
    Returns:
        Flask application instance
    """
    # Set instance path to absolute path
    instance_path = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'instance'))
    app = Flask(__name__, instance_path=instance_path, instance_relative_config=True)
    
    # Load configuration
    if config_name == 'production':
        config = ProductionConfig
    elif config_name == 'testing':
        config = TestingConfig
    else:
        config = DevelopmentConfig
    
    app.config.from_object(config)
    
    # Initialize extensions
    db.init_app(app)
    bcrypt.init_app(app)
    login_manager.init_app(app)
    migrate.init_app(app, db)
    cache.init_app(app)
    
    # Configure Flask-Login
    configure_login_manager(app)
    
    # Register components
    register_blueprints(app)
    register_error_handlers(app)
    register_commands(app)
    register_context_processors(app)
    register_template_filters(app)
    
    return app


def register_blueprints(app):
    """Register application blueprints"""
    from app.blueprints.main import main_bp
    from app.blueprints.auth import auth_bp
    from app.blueprints.admin import admin_bp
    from app.blueprints.players import players_bp
    from app.blueprints.groups import groups_bp
    from app.blueprints.content import content_bp
    from app.blueprints.playlist import playlist_bp
    from app.blueprints.api import api_bp
    
    # Register blueprints (using URL prefixes from blueprint definitions)
    app.register_blueprint(main_bp)
    app.register_blueprint(auth_bp)
    app.register_blueprint(admin_bp)
    app.register_blueprint(players_bp)
    app.register_blueprint(groups_bp)
    app.register_blueprint(content_bp)
    app.register_blueprint(playlist_bp)
    app.register_blueprint(api_bp)


def configure_login_manager(app):
    """Configure Flask-Login"""
    from app.models.user import User
    
    login_manager.login_view = 'auth.login'
    login_manager.login_message = 'Please log in to access this page.'
    login_manager.login_message_category = 'info'
    
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))


def register_error_handlers(app):
    """Register error handlers"""
    
    @app.errorhandler(404)
    def not_found(error):
        return render_template('errors/404.html'), 404
    
    @app.errorhandler(403)
    def forbidden(error):
        return render_template('errors/403.html'), 403
    
    @app.errorhandler(500)
    def internal_error(error):
        db.session.rollback()
        return render_template('errors/500.html'), 500
    
    @app.errorhandler(413)
    def request_entity_too_large(error):
        return render_template('errors/413.html'), 413
    
    @app.errorhandler(408)
    def request_timeout(error):
        return render_template('errors/408.html'), 408


def register_commands(app):
    """Register CLI commands"""
    import click
    
    @app.cli.command('init-db')
    def init_db():
        """Initialize the database"""
        db.create_all()
        click.echo('Database initialized.')
    
    @app.cli.command('create-admin')
    @click.option('--username', default='admin', help='Admin username')
    @click.option('--password', prompt=True, hide_input=True, help='Admin password')
    def create_admin(username, password):
        """Create an admin user"""
        from app.models.user import User
        
        # Check if user exists
        if User.query.filter_by(username=username).first():
            click.echo(f'User {username} already exists.')
            return
        
        # Create admin user
        hashed_password = bcrypt.generate_password_hash(password).decode('utf-8')
        admin = User(username=username, password=hashed_password, role='admin')
        db.session.add(admin)
        db.session.commit()
        click.echo(f'Admin user {username} created successfully.')
    
    @app.cli.command('seed-db')
    def seed_db():
        """Seed database with sample data (development only)"""
        if app.config['ENV'] == 'production':
            click.echo('Cannot seed database in production.')
            return
        
        click.echo('Seeding database with sample data...')
        # Add your seeding logic here
        click.echo('Database seeded successfully.')


def register_context_processors(app):
    """Register context processors for templates"""
    from flask_login import current_user
    
    @app.context_processor
    def inject_config():
        """Inject configuration variables into all templates"""
        return {
            'server_version': app.config['SERVER_VERSION'],
            'build_date': app.config['BUILD_DATE'],
            'logo_exists': os.path.exists(
                os.path.join(app.root_path, app.config['UPLOAD_FOLDERLOGO'], 'logo.png')
            )
        }
    
    @app.context_processor
    def inject_user_theme():
        """Inject user theme preference"""
        theme = 'light'
        if current_user.is_authenticated and hasattr(current_user, 'theme'):
            theme = current_user.theme
        return {'theme': theme}


def register_template_filters(app):
    """Register custom Jinja2 template filters"""
    from datetime import datetime, timezone
    
    @app.template_filter('localtime')
    def localtime_filter(dt, format='%Y-%m-%d %H:%M'):
        """Convert UTC datetime to local time and format it.
        
        Args:
            dt: datetime object in UTC
            format: strftime format string
            
        Returns:
            Formatted datetime string in local timezone
        """
        if dt is None:
            return ''
        
        # If datetime is naive (no timezone), assume it's UTC
        if dt.tzinfo is None:
            dt = dt.replace(tzinfo=timezone.utc)
        
        # Convert to local time
        local_dt = dt.astimezone()
        
        return local_dt.strftime(format)


# For backwards compatibility and direct running
if __name__ == '__main__':
    app = create_app()
    app.run(host='0.0.0.0', port=5000, debug=True)