import os

import yaml
from flask import Flask

from tofu_api.api import TofuApiBlueprint
from tofu_api.config import DefaultConfig
from tofu_api.dependencies import Dependencies


class App(Flask):
    """
    Flask application for Tofu API.
    """
    # Dependencies container
    dependencies: Dependencies

    def __init__(self):
        # Set instance path to the project root directory
        project_root_dir = os.path.abspath('.')

        # Create and configure the app
        super().__init__(
            'tofu_api',
            instance_path=project_root_dir,
            instance_relative_config=True,
        )
        self.config.from_object(DefaultConfig)

        # Load app configuration from YAML file
        self.config.from_file(os.getenv('FLASK_CONFIG_FILE', default='config.yml'), load=yaml.safe_load)

        # Initialize DI container
        self.dependencies = Dependencies()

        # Initialize dependencies
        self.init_database()

        # Register blueprints
        self.register_blueprint(TofuApiBlueprint(self))

    def init_database(self) -> None:
        """
        Initialize database connection and models.
        """
        # Initialize SQLAlchemy, create the database engine based on the app config
        db = self.dependencies.get_sqlalchemy()
        db.init_database(self)

        # Import models to fill the metadata object
        import tofu_api.models  # noqa (unused import)

        # Create all tables
        # TODO: Use migrations instead
        db.create_all_tables()


def create_app() -> Flask:
    """
    App factory, returns a Flask app object.
    """
    return App()