"""Team Tryouts Application - Flask Application Factory.

This module provides the application factory for creating and configuring
the Flask application instance.
"""

import os
from flask import Flask, request, redirect
from extensions import db, login_manager, csrf, hash_password, check_password, limiter
from sqlalchemy import text
import markupsafe
from dotenv import load_dotenv

load_dotenv()


def nl2br(value):
    """Convert newlines to HTML line breaks.
    
    Args:
        value: String value to convert.
        
    Returns:
        Markup: HTML-safe string with line breaks.
    """
    if value:
        return markupsafe.Markup('<br>'.join(str(value).splitlines()))
    return ''


def create_app():
    """Create and configure the Flask application.
    
    Initializes Flask with:
        - Secret key for session security
        - Database configuration
        - CSRF protection
        - Login manager
        - All route blueprints
        - Security headers and HTTPS redirects
        
    Handles database initialization and seeding with sample data if empty.
    
    Returns:
        Flask: Configured Flask application instance.
    """
    app = Flask(__name__)
    app.config['SECRET_KEY'] = os.getenv('SECRET_KEY')
    if not app.config['SECRET_KEY']:
        raise RuntimeError('SECRET_KEY environment variable must be set for security')
    app.config['SQLALCHEMY_DATABASE_URI'] = os.getenv('DATABASE_URL', 'sqlite:///team_tryouts.db')
    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
    app.config['WTF_CSRF_ENABLED'] = True

    # Secure session cookie settings
    app.config['SESSION_COOKIE_SECURE'] = os.getenv('SESSION_COOKIE_SECURE', 'true').lower() == 'true'
    app.config['SESSION_COOKIE_HTTPONLY'] = True
    app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'
    app.config['PERMANENT_SESSION_LIFETIME'] = 3600  # 1 hour session timeout

    db.init_app(app)
    login_manager.init_app(app)
    csrf.init_app(app)
    limiter.init_app(app)

    from routes.auth import auth_bp
    from routes.tryouts import tryouts_bp
    from routes.evaluations import evaluations_bp
    from routes.users import users_bp
    from routes.main import main_bp
    from routes.teams import teams_bp
    from routes.matches import matches_bp

    app.register_blueprint(auth_bp)
    app.register_blueprint(tryouts_bp)
    app.register_blueprint(evaluations_bp)
    app.register_blueprint(users_bp)
    app.register_blueprint(main_bp)
    app.register_blueprint(teams_bp)
    app.register_blueprint(matches_bp)

    # Register custom Jinja filters
    app.jinja_env.filters['nl2br'] = nl2br

    # Add security headers to all responses
    @app.after_request
    def add_security_headers(response):
        response.headers['X-Content-Type-Options'] = 'nosniff'
        response.headers['X-Frame-Options'] = 'DENY'
        response.headers['X-XSS-Protection'] = '1; mode=block'
        response.headers['Content-Security-Policy'] = "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; font-src 'self'; connect-src 'self'; frame-ancestors 'none';"
        response.headers['Strict-Transport-Security'] = 'max-age=31536000; includeSubDomains'
        return response

    # Force HTTPS in production (when not in debug mode)
    @app.before_request
    def force_https():
        if not app.debug:
            if not request.is_secure and request.headers.get('X-Forwarded-Proto') != 'https':
                if os.getenv('FORCE_HTTPS', 'true').lower() == 'true':
                    return redirect(request.url.replace('http://', 'https://'), code=301)

    with app.app_context():
        import models
        from models import User, MatchParticipant
        try:
            # Check if the database schema is up to date by testing a query
            # that uses all model columns including team_side for match participants
            db.session.execute(text('SELECT games, team_side FROM match_participants LIMIT 1'))
            db.create_all()
        except Exception:
            # If there's a schema mismatch, drop and recreate all tables
            db.session.rollback()
            db.drop_all()
            db.create_all()
        
        # Seed database if empty
        if User.query.count() == 0:
            from seed import seed_database
            seed_database()

    # Start the Discord bot for notifications
    try:
        from discord_bot import start_bot
        start_bot()
    except Exception as e:
        import logging
        logging.getLogger(__name__).warning(f"Could not start Discord bot: {e}")

    return app


if __name__ == '__main__':
    app = create_app()
    # Debug mode should only be enabled via environment variable for security
    debug_mode = os.environ.get('FLASK_DEBUG', 'false').lower() == 'true'
    app.run(debug=debug_mode, host='0.0.0.0', port=5000)