from flask import Flask, jsonify
import os
from flask_swagger_ui import get_swaggerui_blueprint
from flask_cors import CORS
from app.config import Config
from app.api.routes import api, auth_bp
from app.errors import register_error_handlers
from flask_jwt_extended import JWTManager

def create_app():
    """ Factory function to create a Flask app instance """
    app = Flask(__name__)
    
   

    # Load configuration
    app.config.from_object(Config)
    jwt = JWTManager(app)

    CORS(app)

    # Swagger Doc
    SWAGGER_URL = app.config.get("SWAGGER_URL")
    API_URL = app.config.get("API_URL")

    # Register blueprints with /api prefix for the main API routes
    app.register_blueprint(api, url_prefix='/api')
    # Register blueprints with /auth prefix for the authentication routes
    app.register_blueprint(auth_bp, url_prefix='/api/Auth')

    swagger_ui_blueprint = get_swaggerui_blueprint(SWAGGER_URL, API_URL)
    app.register_blueprint(swagger_ui_blueprint, url_prefix=SWAGGER_URL)
    
    def jwt_error(message, code=401):
        return jsonify({
            "status": "error",
            "message": message
        }), code


    @jwt.unauthorized_loader
    def unauthorized_response(callback):
        return jwt_error("Unauthorized access")

    @jwt.expired_token_loader
    def expired_token_callback(jwt_header, jwt_payload):
        return jwt_error("Expired token")

    @jwt.invalid_token_loader
    def invalid_token_callback(error):
        return jwt_error("Invalid authentication token.", 422)

    @jwt.revoked_token_loader
    def revoked_token_callback(jwt_header, jwt_payload):
        return jwt_error("This token has been revoked. Please log in again.")

   
    # Error Handlers
    register_error_handlers(app)

    return app