import os
import logging
from datetime import datetime

from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.orm import DeclarativeBase
from werkzeug.middleware.proxy_fix import ProxyFix
from flask_login import LoginManager
from flask_wtf.csrf import CSRFProtect

# Set up logging
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)

# Define base class for SQLAlchemy models
class Base(DeclarativeBase):
    pass

# Initialize extensions
db = SQLAlchemy(model_class=Base)
csrf = CSRFProtect()
login_manager = LoginManager()

# Create Flask application
app = Flask(__name__)

# Configure application
app.secret_key = os.environ.get("SESSION_SECRET", "dev-secret-key")
app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1, x_host=1)

# Configure database
app.config["SQLALCHEMY_DATABASE_URI"] = os.environ.get("DATABASE_URL", "sqlite:///forrum.db")
app.config["SQLALCHEMY_ENGINE_OPTIONS"] = {
    "pool_recycle": 300,
    "pool_pre_ping": True,
}

# Initialize extensions with app
db.init_app(app)
csrf.init_app(app)
login_manager.init_app(app)

# Configure login manager
login_manager.login_view = "auth.login"
login_manager.login_message = "Please log in to access this page."
login_manager.login_message_category = "info"

# Import models (must be after db initialization but before create_all)
from models import User

# Register blueprints
with app.app_context():
    from routes.auth import auth_bp
    from routes.forum import forum_bp
    from routes.user import user_bp
    from routes.admin import admin_bp
    from routes.cadmin import cadmin_bp

    app.register_blueprint(auth_bp)
    app.register_blueprint(forum_bp)
    app.register_blueprint(user_bp)
    app.register_blueprint(admin_bp)
    app.register_blueprint(cadmin_bp)

    # Create database tables
    db.create_all()

    # Import utility functions
    from utils import format_datetime
    
    # Add template filters
    app.jinja_env.filters['format_datetime'] = format_datetime
    
    # Context processor for template variables
    @app.context_processor
    def utility_processor():
        return {
            'now': datetime.utcnow
        }

    # User loader for Flask-Login
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))

    # Error handlers
    @app.errorhandler(404)
    def page_not_found(e):
        return render_template('errors/404.html'), 404

    @app.errorhandler(403)
    def forbidden(e):
        return render_template('errors/403.html'), 403

    @app.errorhandler(500)
    def internal_server_error(e):
        return render_template('errors/500.html'), 500

    # Ensure required directories exist
    upload_dir = os.path.join(app.static_folder, 'uploads')
    avatar_dir = os.path.join(upload_dir, 'avatars')
    
    if not os.path.exists(upload_dir):
        os.makedirs(upload_dir)
    if not os.path.exists(avatar_dir):
        os.makedirs(avatar_dir)

    logger.debug("Application initialized successfully")