from flask import jsonify
from flask.views import MethodView
from sqlalchemy.orm import Session
from werkzeug.exceptions import NotFound

from tofu_api.common.rest import BaseBlueprint
from tofu_api.models import Task


class TaskApiBlueprint(BaseBlueprint):
    """
    Blueprint for the tasks REST API.
    """

    # Blueprint settings
    name = 'rest_api_tasks'
    import_name = __name__
    url_prefix = '/tasks'

    def init_blueprint(self) -> None:
        """
        Register URL rules.
        """
        db_session = self.app.dependencies.get_db_session()

        self.add_url_rule(
            '',
            view_func=self.create_view_func(TaskCollectionView, db_session=db_session),
            methods=['GET', 'POST'],
        )
        self.add_url_rule(
            '/<int:task_id>',
            view_func=self.create_view_func(TaskItemView, db_session=db_session),
            methods=['GET', 'PATCH', 'DELETE'],
        )


class TaskBaseView(MethodView):
    """
    Base class for view classes for the `/tasks` endpoint.
    """

    # TODO: Use a handler class instead of accessing the database session directly
    db_session: Session

    def __init__(self, *, db_session: Session):
        self.db_session = db_session


class TaskCollectionView(TaskBaseView):
    """
    View class for `/tasks` endpoint.
    """

    def get(self):
        """
        Get list of all tasks.
        """
        task_list = self.db_session.query(Task).all()
        return jsonify({
            'count': len(task_list),
            'items': [task.to_dict() for task in task_list],
        }), 200

    def post(self):
        """
        Create a new task.
        """
        # TODO: Parse request data and create real data
        new_task = Task(
            title='Do stuff'
        )
        self.db_session.add(new_task)
        self.db_session.commit()
        return jsonify(new_task.to_dict()), 201


class TaskItemView(TaskBaseView):
    """
    View class for `/tasks/<int:task_id>` endpoint.
    """

    def get(self, task_id: int):
        """
        Get a single task by ID.
        """
        task = self.db_session.query(Task).get(task_id)
        if task is None:
            raise NotFound(f'Task with ID {task_id} not found!')
        return jsonify(task.to_dict()), 200

    def patch(self, task_id: int):
        """
        Update a single task by ID.
        """
        # TODO: Implement
        raise NotImplementedError

    def delete(self, task_id: int):
        """
        Delete a single task by ID.
        """
        # TODO: Implement
        raise NotImplementedError