# backend/myapp/__init__.py

import sys
import os
from flask import Flask, jsonify

# --- 1. Import Extensions ---
# Import specific extension instances defined in extensions.py
# Avoid 'import *'
try:
    from .extensions import mongo, cors # Add other extensions like jwt, ma if used
except ImportError as e:
    print(f"Error importing extensions: {e}. Make sure extensions.py exists and defines instances.")
    # Provide dummy instances or raise an error if extensions are critical
    mongo = None
    cors = None

# --- 2. Import Default Config ---
# Assumes config.py is in the parent 'backend' directory. Adjust if moved.
try:
    # This relative import works if 'backend' is treated as a package or is in sys.path
    from .config import Config, config as config_options # Assuming config.py has a 'config' dict for selection
except ImportError:
    print("Warning: Could not import default config from parent directory.")
    # Define a minimal fallback Config class
    class Config:
        SECRET_KEY = os.environ.get('SECRET_KEY') or 'a-default-fallback-secret-key'
        DEBUG = False
    config_options = {'default': Config}


def create_app(config_name='default') -> Flask:
    """
    Creates and configures the Flask application instance.
    Uses the Application Factory pattern.
    """
    # === Step 1: Create Flask App ===
    # Enable loading from the instance/ folder relative to the 'backend' directory
    app = Flask(__name__, instance_relative_config=True)

    # === Step 2: Load Configuration ===
    # Load default config based on config_name (if using different configs)
    selected_config = config_options.get(config_name, Config)
    app.config.from_object(selected_config)

    # Load instance config (/instance/config.py) - Overrides defaults
    # silent=True prevents errors if the file doesn't exist
    app.config.from_pyfile('config.py', silent=True)

    # === Step 3: Initialize Extensions ===
    if mongo:
        try:
            mongo.init_app(app)
            print("PyMongo initialized successfully.")
        except Exception as e:
            print(f"Error initializing PyMongo: {e}")

    if cors:
        try:
            # Configure CORS using settings from app.config
            frontend_origin = "http://localhost:5173"
            cors.init_app(app, resources={r"/api/*": {"origins": app.config.get('FRONTEND_ORIGIN', '*')}}, supports_credentials=True)
            print("CORS initialized successfully.")
        except Exception as e:
            print(f"Error initializing CORS: {e}")

    # if jwt:
    #     try:
    #         jwt.init_app(app)
    #         print("JWTManager initialized successfully.")
    #     except Exception as e:
    #         print(f"Error initializing JWTManager: {e}")
    # Add init_app calls for other extensions (ma, migrate, etc.) here

    # === Step 4: Register Blueprints ===
    # Use unique variable names and appropriate prefixes
    try:
        # Assuming each blueprint's __init__.py defines an object named 'bp'
        from .auth import bp as auth_bp # checked
        from .ai_services import bp as ai_services_bp
        from .activity import bp as activity_bp
        from .dialog import bp as dialog_bp
        from .projects import bp as projects_bp # checked
        from .urls import bp as urls_bp

        # Register with potentially more specific prefixes
        app.register_blueprint(auth_bp, url_prefix='/api')
        app.register_blueprint(ai_services_bp, url_prefix="/api/ai") # Changed prefix
        app.register_blueprint(activity_bp, url_prefix='/api/activity')
        app.register_blueprint(projects_bp, url_prefix='/api/projects')
        app.register_blueprint(dialog_bp, url_prefix="/api/dialog")
        app.register_blueprint(urls_bp, url_prefix="/api/urls")
        print("Blueprints registered successfully.")

    except (ModuleNotFoundError, ImportError) as e:
        print(f"Error importing or registering blueprints: {e}. Check blueprint structure and 'bp' variable names.")
    except Exception as e:
        print(f"An unexpected error occurred during blueprint registration: {e}")


    # === Step 5: Add Root Route (Optional) ===
    @app.route("/")
    def index():
        # You could add a check here to see if mongo connection is working
        db_status = "disconnected"
        if mongo:
            try:
                # The ismaster command is cheap and does not require auth.
                mongo.cx.admin.command('ismaster')
                db_status = "connected"
            except Exception:
                db_status = "connection error"
        return jsonify({"message": "Backend service is running!", "database_status": db_status})

    # You can also add other app-wide error handlers here if needed
    @app.errorhandler(404)
    def page_not_found(e):
       return jsonify(error=str(e)), 404

    print(f"App created with config: {config_name}")
    print(f"Instance path: {app.instance_path}") # Check instance path

    return app