import json
import time

import mongoengine
from flask import jsonify, request
from flask_views.base import View
from mongoengine import ValidationError, DoesNotExist, InvalidQueryError
from werkzeug.exceptions import Unauthorized, NotFound

from restapi.resource import Resource


class ApiView(View):
    model = None
    authentication_methods = []

    def __init__(self, model):
        self.start = time.time()
        self.model = model
        self.resource = Resource(self.model)

    def dispatch_request(self, *args, **kwargs):
        # keep all the logic in a helper method (_dispatch_request) so that
        # it's easy for subclasses to override this method without them also having to copy/paste all the
        # authentication logic, etc.
        return self._dispatch_request(*args, **kwargs)

    def _dispatch_request(self, *args, **kwargs):
        authorized = True if len(self.authentication_methods) == 0 else False
        for authentication_method in self.authentication_methods:
            if authentication_method().authorized():
                authorized = True
        if not authorized:
            return {'error': 'Unauthorized'}, '401 Unauthorized'

        try:
            return super(ApiView, self).dispatch_request(*args, **kwargs)
        except mongoengine.queryset.DoesNotExist as e:
            return {'error': 'Empty query: ' + str(e)}, '404 Not Found'
        except ValidationError as e:
            return e.args[0], '400 Bad Request'
        except Unauthorized:
            return {'error': 'Unauthorized'}, '401 Unauthorized'
        except NotFound as e:
            return {'error': str(e)}, '404 Not Found'

    def get(self, *args, **kwargs):
        """
        TODO: check permissions
        :param args:
        :param kwargs:
        :return:
        """
        if 'pk' in kwargs:
            try:
                qs = self.resource.to_qs(pk=kwargs.get('pk'))
                count, data = self.resource.to_json(pk=kwargs.get('pk'))
                response = {
                    'response': data,
                    'status': True,
                    'info': {
                        'took': time.time() - self.start
                    },
                }
            except (ValidationError, DoesNotExist) as e:
                kwargs.update({'code': 404})
                response = {
                    "status": False,
                    "errors": "Object not found"
                }
        else:
            if "query" in request.args and self.model._meta.get('can_query'):
                self.resource.external_query(json.loads(request.args.get('query')))
            count, data = self.resource.to_json()
            response = {
                'response': data,
                'info': {
                    'offset': self.resource.offset,
                    'limit': self.resource.limit,
                    'status': True,
                    'total': count,
                    'took': time.time() - self.start
                },
            }

        return jsonify(response), kwargs.get('code', 200)

    def post(self, *args, **kwargs):
        """
        TODO: check permissions

        :param args:
        :param kwargs:
        :return:
        """
        try:
            item = self.model(**request.json)
            item.validate()
        except ValidationError as v:
            return jsonify({
                'status': False,
                'errors': [{"field": field, "error": str(error)} for field, error in v.__dict__.get('errors').items() if
                           isinstance(error, ValidationError) and field[0] != "_"]
            }), 400
        except Exception as e:
            return jsonify({
                'status': False,
                'errors': str(e)
            }), 400
        data = item.save()
        return self.get(pk=data.id, code=201)

    def put(self, *args, **kwargs):
        """
        TODO: check permissions

        :param args:
        :param kwargs:
        :return:
        """
        if "pk" not in kwargs:
            return jsonify({
                'status': False,
                "error": "Method not allowed"
            }), 403
        else:
            try:
                self.model.objects(id=kwargs.get('pk')).update(**request.json)
                return self.get(pk=kwargs.get('pk'))
            except ValidationError as v:
                print(v.__dict__)
                return jsonify({
                    'status': False,
                    'errors': [{"field": v.__dict__.get('field_name'), "error": v.__dict__.get('_message')}]
                }), 400
            except InvalidQueryError as e:
                return jsonify({
                    'status': False,
                    'errors': str(e)
                }), 400

    def has_read_permission(self, request, qs):
        return qs

    def has_add_permission(self, request, obj):
        return True

    def has_change_permission(self, request, obj):
        return True

    def has_delete_permission(self, request, obj):
        return True

    def delete(self, *args, **kwargs):
        "delete method"