import json

from django.test import TestCase, Client

DEFAULT_GRAPHQL_URL = "/graphql/"


def graphql_query(
    query,
    op_name=None,
    input_data=None,
    variables=None,
    headers=None,
    client=None,
    graphql_url=None,
):
    """
    Args:
        query (string)              - GraphQL query to run
        op_name (string)            - If the query is a mutation or named query, you must
                                      supply the op_name.  For annon queries ("{ ... }"),
                                      should be None (default).
        input_data (dict)           - If provided, the $input variable in GraphQL will be set
                                      to this value. If both ``input_data`` and ``variables``,
                                      are provided, the ``input`` field in the ``variables``
                                      dict will be overwritten with this value.
        variables (dict)            - If provided, the "variables" field in GraphQL will be
                                      set to this value.
        headers (dict)              - If provided, the headers in POST request to GRAPHQL_URL
                                      will be set to this value.
        client (django.test.Client) - Test client. Defaults to django.test.Client.
        graphql_url (string)        - URL to graphql endpoint. Defaults to "/graphql".

    Returns:
        Response object from client
    """
    if client is None:
        client = Client()
    if not graphql_url:
        graphql_url = DEFAULT_GRAPHQL_URL

    body = {"query": query}
    if op_name:
        body["operationName"] = op_name
    if variables:
        body["variables"] = variables
    if input_data:
        if "variables" in body:
            body["variables"]["input"] = input_data
        else:
            body["variables"] = {"input": input_data}
    if headers:
        resp = client.post(
            graphql_url, json.dumps(body), content_type="application/json", **headers
        )
    else:
        resp = client.post(
            graphql_url, json.dumps(body), content_type="application/json"
        )
    return resp


class GraphQLTestCase(TestCase):
    """
    Based on: https://www.sam.today/blog/testing-graphql-with-graphene-django/
    """

    # URL to graphql endpoint
    GRAPHQL_URL = DEFAULT_GRAPHQL_URL

    @classmethod
    def setUpClass(cls):
        super(GraphQLTestCase, cls).setUpClass()

        cls._client = Client()

    def query(self, query, op_name=None, input_data=None, variables=None, headers=None):
        """
        Args:
            query (string)    - GraphQL query to run
            op_name (string)  - If the query is a mutation or named query, you must
                                supply the op_name.  For annon queries ("{ ... }"),
                                should be None (default).
            input_data (dict) - If provided, the $input variable in GraphQL will be set
                                to this value. If both ``input_data`` and ``variables``,
                                are provided, the ``input`` field in the ``variables``
                                dict will be overwritten with this value.
            variables (dict)  - If provided, the "variables" field in GraphQL will be
                                set to this value.
            headers (dict)    - If provided, the headers in POST request to GRAPHQL_URL
                                will be set to this value.

        Returns:
            Response object from client
        """
        return graphql_query(
            query,
            op_name=op_name,
            input_data=input_data,
            variables=variables,
            headers=headers,
            client=self._client,
            graphql_url=self.GRAPHQL_URL,
        )

    def assertResponseNoErrors(self, resp, msg=None):
        """
        Assert that the call went through correctly. 200 means the syntax is ok, if there are no `errors`,
        the call was fine.
        :resp HttpResponse: Response
        """
        content = json.loads(resp.content)
        self.assertEqual(resp.status_code, 200, msg or content)
        self.assertNotIn("errors", list(content.keys()), msg or content)

    def assertResponseHasErrors(self, resp, msg=None):
        """
        Assert that the call was failing. Take care: Even with errors, GraphQL returns status 200!
        :resp HttpResponse: Response
        """
        content = json.loads(resp.content)
        self.assertIn("errors", list(content.keys()), msg or content)