# ==============================================================================
# Formeleon - Multi-tenant Form Generator
# Author: Björn Runden <br@runden.net>
# Module: app.py
# Description: Main Flask application initialization and Blueprint registration.
#              Sets up database, configuration, and registers all route blueprints.
# ==============================================================================

"""
Main Flask application module for Formeleon.

This module:
- Loads application configuration
- Initializes Flask extensions (SQLAlchemy, Migrate, CORS, Session)
- Registers all route blueprints (API, Admin, Auth)
- Sets up error handlers
- Provides utility functions for request context

The application uses Flask Blueprints for modular route organization:
- /api/v1/* - Public Form API for form submissions
- /admin/* - Admin Dashboard for form management
- /auth/* - Authentication routes (OIDC callbacks, logout)
"""

import os
import logging
from typing import Optional

from flask import Flask, request, session, g
from flask_cors import CORS
from flask_session import Session
from flask_migrate import Migrate
import uuid

# corrected for py3.13 from config import Config, config_map
from config import Config, config_map
from models import db, Tenant, User, UserRole, Submission, FormConfig, AuditLog, SubmissionStatus


# Initialize extensions globally (will be bound to app in create_app)
migrate = Migrate()
cors = CORS()


def get_config_class() -> type:
    """
    Get the appropriate configuration class based on FLASK_ENV.
    
    :return: Configuration class to use
    """
    env = os.environ.get('FLASK_ENV', 'development')
    return config_map.get(env, Config)


def create_app(config_class: Optional[type] = None) -> Flask:
    """
    Create and configure the Flask application instance.
    
    :param config_class: Configuration class to use (defaults to environment-based)
    :return: Configured Flask application instance
    """
    # Initialize Flask app
    app = Flask(__name__)
    app.config.from_object(config_class or get_config_class())
    
    # Set up logging
    setup_logging(app)
    
    # Initialize extensions with app
    initialize_extensions(app)
    
    # Register blueprints
    register_blueprints(app)
    
    # Register error handlers
    register_error_handlers(app)
    
    # Register CLI commands
    register_cli_commands(app)
    
    # Set up dev mode middleware if enabled
    if app.config['DEV_MODE']:
        setup_dev_mode_middleware(app)
    
    return app


def setup_logging(app: Flask) -> None:
    """
    Configure logging for the application.
    
    :param app: Flask application instance
    """
    log_level = logging.DEBUG if app.config['DEBUG'] else logging.INFO
    logging.basicConfig(
        level=log_level,
        format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
    )
    app.logger.setLevel(log_level)
    
    # Suppress Flask-SQLAlchemy logs unless in debug mode
    if not app.config['DEBUG']:
        logging.getLogger('flask_sqlalchemy').setLevel(logging.WARNING)


def initialize_extensions(app: Flask) -> None:
    """
    Initialize Flask extensions with the application.
    
    :param app: Flask application instance
    """
    # Database
    db.init_app(app)
    
    # Migration
    migrate.init_app(app, db)
    
    # CORS
    if app.config['ENABLE_CORS']:
        cors.init_app(app, resources={
            r'/api/*': {
                'origins': app.config.get('ALLOWED_ORIGINS', '*'),
                'methods': ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
                'allow_headers': ['Content-Type', 'Authorization', 'X-Request-ID']
            }
        })
    
    # Session
    app.config['SESSION_TYPE'] = 'sqlalchemy'
    app.config['SESSION_SQLALCHEMY'] = db
    Session(app)
    
    # Ensure secret key is set
    if not app.config.get('SECRET_KEY'):
        app.config['SECRET_KEY'] = str(uuid.uuid4())
        app.logger.warning('Generated random SECRET_KEY - set explicitly in production!')


def register_blueprints(app: Flask) -> None:
    """
    Register all route blueprints with the application.
    
    :param app: Flask application instance
    """
    # Import blueprints here to avoid circular imports
    from routes.api import api_bp
    from routes.admin import admin_bp
    from routes.auth import auth_bp
    
    # Register blueprints with URL prefixes
    app.register_blueprint(api_bp, url_prefix='/api/v1')
    app.register_blueprint(admin_bp, url_prefix='/admin')
    app.register_blueprint(auth_bp, url_prefix='/auth')
    
    # Register root route for health check
    @app.route('/')
    def health_check():
        """Health check endpoint."""
        return {
            'status': 'ok',
            'version': '1.0.0',
            'dev_mode': app.config['DEV_MODE']
        }, 200


def register_error_handlers(app: Flask) -> None:
    """
    Register custom error handlers for the application.
    
    :param app: Flask application instance
    """
    @app.errorhandler(400)
    def bad_request_error(error):
        """Handle 400 Bad Request errors."""
        return {
            'error': 'Bad Request',
            'message': str(error.description) if error.description else 'Invalid request data'
        }, 400
    
    @app.errorhandler(401)
    def unauthorized_error(error):
        """Handle 401 Unauthorized errors."""
        return {
            'error': 'Unauthorized',
            'message': str(error.description) if error.description else 'Authentication required'
        }, 401
    
    @app.errorhandler(403)
    def forbidden_error(error):
        """Handle 403 Forbidden errors."""
        return {
            'error': 'Forbidden',
            'message': str(error.description) if error.description else 'Access denied'
        }, 403
    
    @app.errorhandler(404)
    def not_found_error(error):
        """Handle 404 Not Found errors."""
        return {
            'error': 'Not Found',
            'message': str(error.description) if error.description else 'Resource not found'
        }, 404
    
    @app.errorhandler(429)
    def too_many_requests_error(error):
        """Handle 429 Too Many Requests errors."""
        return {
            'error': 'Too Many Requests',
            'message': str(error.description) if error.description else 'Rate limit exceeded'
        }, 429
    
    @app.errorhandler(500)
    def internal_server_error(error):
        """Handle 500 Internal Server Error."""
        app.logger.error(f'Internal Server Error: {error}')
        return {
            'error': 'Internal Server Error',
            'message': 'An unexpected error occurred'
        }, 500


def register_cli_commands(app: Flask) -> None:
    """
    Register custom CLI commands for the application.
    
    :param app: Flask application instance
    """
    import click
    from flask.cli import with_appcontext
    
    @app.cli.command('seed-db')
    @with_appcontext
    def seed_db():
        """Seed the database with test data for development."""
        import uuid
        
        # Check if data already exists
        if Tenant.query.first():
            print('Database already contains data. Use --force to overwrite.')
            return
        
        # Create dev tenant
        tenant = Tenant(
            id='tenant_dev_123',
            name='Development Tenant',
            public_key='dev-public-key-12345',
            allowed_origins='http://localhost:5000,http://localhost:8080',
            status=TenantStatus.ACTIVE
        )
        db.session.add(tenant)
        
        # Create sample form
        sample_form = FormConfig(
            id='form_sample_001',
            tenant_id='tenant_dev_123',
            name='Contact Form',
            description='Sample contact form for testing',
            form_structure={
                'version': '1.0',
                'fields': [
                    {
                        'name': 'name',
                        'type': 'text',
                        'label': 'Your Name',
                        'required': True,
                        'validation': {'min_length': 2, 'max_length': 100}
                    },
                    {
                        'name': 'email',
                        'type': 'email',
                        'label': 'Email Address',
                        'required': True,
                        'validation': {'pattern': r'^[^@]+@[^@]+\.[^@]+$'}
                    },
                    {
                        'name': 'subject',
                        'type': 'text',
                        'label': 'Subject',
                        'required': True
                    },
                    {
                        'name': 'message',
                        'type': 'textarea',
                        'label': 'Message',
                        'required': True,
                        'validation': {'min_length': 10}
                    }
                ],
                'submit_button': {
                    'text': 'Send Message',
                    'style': 'primary'
                }
            },
            settings={
                'email_notification': {
                    'enabled': False,
                    'recipients': ['admin@formeleon.local']
                },
                'success_message': 'Thank you for your message!',
                'recaptcha_enabled': True
            }
        )
        db.session.add(sample_form)
        
        # Create dev admin user
        admin_user = User(
            id='user_dev_admin_001',
            email=app.config.get('DEV_USER_EMAIL', 'dev@formeleon.local'),
            name=app.config.get('DEV_USER_NAME', 'Dev Admin'),
            role=UserRole.ADMIN,
            sub='dev-admin-sub-123'
        )
        db.session.add(admin_user)
        
        # Associate user with tenant
        from models import user_tenant_association
        db.session.execute(
            user_tenant_association.insert().values(
                user_id=admin_user.id,
                tenant_id=tenant.id
            )
        )
        
        db.session.commit()
        print(f'Seeded database with tenant {tenant.id}, form {sample_form.id}, and user {admin_user.id}')
    
    @app.cli.command('create-tenant')
    @click.argument('name')
    @click.argument('public_key')
    @click.option('--allowed-origins', default='*', help='Comma-separated allowed origins')
    @with_appcontext
    def create_tenant(name, public_key, allowed_origins):
        """Create a new tenant."""
        tenant_id = f'tenant_{name.lower().replace(" ", "_")}_{str(uuid.uuid4())[:8]}'
        tenant = Tenant(
            id=tenant_id,
            name=name,
            public_key=public_key,
            allowed_origins=allowed_origins
        )
        db.session.add(tenant)
        db.session.commit()
        print(f'Created tenant {tenant_id} with public key {public_key}')
    
    @app.cli.command('create-user')
    @click.argument('email')
    @click.argument('name')
    @click.option('--role', default='user', help='User role: admin, tenant_admin, user, viewer')
    @with_appcontext
    def create_user(email, name, role):
        """Create a new user."""
        from models import UserRole as UR
        role_enum = getattr(UR, role.upper(), UR.USER)
        user_id = f'user_{email.split("@")[0]}_{str(uuid.uuid4())[:8]}'
        user = User(
            id=user_id,
            email=email,
            name=name,
            role=role_enum
        )
        db.session.add(user)
        db.session.commit()
        print(f'Created user {user_id} with email {email} and role {role}')


def setup_dev_mode_middleware(app: Flask) -> None:
    """
    Set up development mode middleware for fake authentication.
    
    This middleware injects a fake Zitadel user session when DEV_MODE is enabled,
    bypassing the need for actual OIDC authentication during development.
    
    :param app: Flask application instance
    """
    from functools import wraps
    
    @app.before_request
    def inject_dev_user():
        """Inject dev user into session if DEV_MODE is enabled."""
        # Skip for static files, auth routes, and API routes
        if (request.path.startswith('/static/') or 
            request.path.startswith('/auth/') or
            request.path.startswith('/api/')):
            return
        
        # Skip if user is already authenticated
        if 'user_id' in session:
            return
        
        # Inject dev user
        dev_user = {
            'id': 'user_dev_admin_001',
            'email': app.config.get('DEV_USER_EMAIL', 'dev@formeleon.local'),
            'name': app.config.get('DEV_USER_NAME', 'Dev Admin'),
            'role': app.config.get('DEV_USER_ROLE', 'admin'),
            'sub': 'dev-admin-sub-123',
            'tenant_id': app.config.get('DEV_TENANT_ID', 'tenant_dev_123'),
            'dev_mode': True
        }
        session['user_id'] = dev_user['id']
        session['user'] = dev_user
        session.permanent = True
        
        # Load or create dev user in database
        from models import User, UserRole, Tenant
        user = User.query.get(dev_user['id'])
        if not user:
            role = UserRole.ADMIN if dev_user['role'] == 'admin' else UserRole.USER
            user = User(
                id=dev_user['id'],
                email=dev_user['email'],
                name=dev_user['name'],
                role=role,
                sub=dev_user['sub']
            )
            db.session.add(user)
            db.session.commit()
        
        # Ensure dev tenant exists
        tenant = Tenant.query.get(dev_user['tenant_id'])
        if not tenant:
            tenant = Tenant(
                id=dev_user['tenant_id'],
                name='Development Tenant',
                public_key='dev-public-key-12345',
                allowed_origins='*'
            )
            db.session.add(tenant)
            db.session.commit()


def get_current_user() -> Optional[User]:
    """
    Get the current authenticated user from the request context.
    
    :return: User object if authenticated, None otherwise
    """
    from flask import session
    if 'user_id' not in session:
        return None
    return User.query.get(session['user_id'])


def get_current_tenant() -> Optional[Tenant]:
    """
    Get the current tenant from the request context.
    
    :return: Tenant object if available, None otherwise
    """
    from flask import session
    if 'tenant_id' in session:
        return Tenant.query.get(session['tenant_id'])
    
    user = get_current_user()
    if user and user.tenants:
        return user.tenants[0]
    
    return None


def get_request_context() -> dict:
    """
    Get standardized request context for audit logging.
    
    :return: Dictionary with request context information
    """
    return {
        'ip_address': request.remote_addr,
        'user_agent': request.user_agent.string if request.user_agent else None,
        'path': request.path,
        'method': request.method
    }


# Create application instance
app = create_app()


if __name__ == '__main__':
    # This allows running the app directly with python app.py
    # In production, use gunicorn or other WSGI servers
    app.run(host='0.0.0.0', port=5000, debug=app.config['DEBUG'])