from flask import jsonify
from flask.views import View
from typing import Callable
from typing import Optional

class ListView(View):
    """
        View that returns a list of instances of a certain class
    """

    # pylint: disable=arguments-differ
    methods = ['GET']
    model = None

    def __init__(self, model_cls: Optional = None, post_process: Optional[Callable] = None):
        self._cls = model_cls or self.model
        self._post_process = post_process

    def dispatch_request(self, **kwargs):
        objects = self.get_objects(**kwargs)
        objects = self.post_process(objects)
        return jsonify(objects)

    def get_objects(self, **kwargs):
        query = self._list_query(**kwargs)
        return self._cls.query.filter_by(**query).all()

    def _list_query(self, **kwargs) -> dict:
        return kwargs

    def post_process(self, objects):
        if self._post_process is None or not callable(self._post_process):
            return objects

        return self._post_process(objects)