from django.views.generic.base import TemplateView

from .query import schema


class GraphQLContextMixin(object):
    # GraphQL query
    query = ''
    # The schema to execute query
    schema = None
    # Variables to be passed to the query
    variables = {}

    def get_query(self):
        """
        Returns the GraphQL query to process.
        """
        return self.query

    def get_schema(self):
        return self.schema

    def get_context_data(self, **kwargs):
        """
        Executes the GraphQL query and set the context data to the response.
        """
        return kwargs

    def get_variables(self, request):
        """
        Returns a dict of variables passed to the GraphQL query.
        """
        return self.variables

    def get(self, request, *args, **kwargs):
        """
        Executes the GraphQL query and add result to the context data before rendering template.
        """
        if not self.get_query():
            return self.render_to_response(self.get_context_data())

        response = self.get_schema().execute(
            self.get_query(),
            args=self.get_variables(request))

        return self.render_to_response(
            self.get_context_data(errors=response.errors,
                                  data=response.data))


class MutationView(GraphQLContextMixin):
    # Mutation query
    mutation = ''

    def post(self, request, *args, **kwargs):
        """
        Executes the mutation and render the template with resulting data in the context.
        """
        if not self.get_mutation():
            return self.render_to_response(self.get_context_data())

        response = self.get_schema().execute(
            self.get_mutation(),
            args=self.get_user_data(request))

        return self.render_to_response(
            self.get_context_data(errors=response.errors,
                                  data=response.data))

    def get_user_data(self, request):
        """
        Returns the user data passed as variables to the mutation query.
        """
        return request.POST

    def get_mutation(self):
        """
        Returns the mutation query.
        """
        return self.mutation


class LoginView(MutationView, TemplateView):
    mutation = '''
    mutation Login($username: String, $password: String) {
        createJWT(username: $username, password: $password) {
            jwt
        }
    }
    '''

    template_name = 'accounts/login.html'

    schema = schema


class ListAllOrganizations(GraphQLContextMixin, TemplateView):
    query = '''
    query GetAllOrganizations {
        allOrganizations {
             name
        }
    }
    '''

    template_name = 'organizations/list_all.html'

    schema = schema