from flask import Flask, g, redirect, url_for, render_template, session
import datetime
import os
import secrets
from app.core.extensions import db, migrate, login_manager, bcrypt, limiter
from app.core.csrf_utils import init_csrf
from app.core.auth import User, load_user
from app.core.context_processors import inject_breadcrumbs


def create_app(config_name="development"):
    app = Flask(__name__, static_folder="static", template_folder="templates")

    # Load configuration
    if config_name == "production":
        app.config.from_object("config.ProductionConfig")
    elif config_name == "testing":
        app.config.from_object("config.TestingConfig")
    else:
        app.config.from_object("config.DevelopmentConfig")

    # Ensure SECRET_KEY is set
    if not app.config.get('SECRET_KEY'):
        app.config['SECRET_KEY'] = secrets.token_hex(32)

    # Initialize extensions
    db.init_app(app)
    migrate.init_app(app, db)
    login_manager.init_app(app)
    bcrypt.init_app(app)
    init_csrf(app)
    limiter.init_app(app)

    # Initialize login manager
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))

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

    # Register template filters
    from app.core.template_filters import bp as filters_bp
    from app.core.template_filters import markdown_filter

    app.register_blueprint(filters_bp)
    
    # Register the markdown filter directly
    app.jinja_env.filters['markdown'] = markdown_filter

    # Create database tables
    with app.app_context():
        try:
            db.create_all()
            print("Database tables created successfully")
        except Exception as e:
            print(f"Error with database setup: {e}")

    # Register blueprints
    from app.routes import auth, dashboard, ipam
    app.register_blueprint(auth.bp)
    app.register_blueprint(dashboard.bp)
    app.register_blueprint(ipam.bp)
    
    # Register API routes
    from app.routes import api
    app.register_blueprint(api.bp)

    from app.routes.importexport import bp as importexport_bp

    app.register_blueprint(importexport_bp)

    # Add static assets blueprint
    from app.routes.static import bp as static_bp

    app.register_blueprint(static_bp)

    # Add session handling
    @app.before_request
    def make_session_permanent():
        session.permanent = True

    # Add error handlers
    @app.errorhandler(404)
    def page_not_found(e):
        return render_template("errors/404.html", title="Page Not Found"), 404

    @app.errorhandler(500)
    def internal_server_error(e):
        return render_template("errors/500.html", title="Server Error"), 500

    @app.errorhandler(403)
    def forbidden(e):
        return render_template("errors/403.html", title="Forbidden"), 403

    # Session configuration
    app.config['SESSION_TYPE'] = 'filesystem'
    app.config['SESSION_FILE_DIR'] = os.path.join(os.getcwd(), 'instance/sessions')
    app.config['SESSION_PERMANENT'] = True
    app.config['PERMANENT_SESSION_LIFETIME'] = 3600  # 1 hour in seconds

    # Ensure the sessions directory exists
    os.makedirs(app.config['SESSION_FILE_DIR'], exist_ok=True)

    # Debug CSRF issues
    @app.after_request
    def after_request(response):
        if app.debug:  # Only in development
            print(f"Session contains CSRF token: {'csrf_token' in session}")
            print(f"CSRF header name: {app.config.get('WTF_CSRF_HEADERS')}")
        return response

    # Register context processors
    app.context_processor(inject_breadcrumbs)

    return app