// @flow
import type { Plugin, Build } from "../SchemaBuilder";
import type { BuildExtensionQuery } from "./QueryPlugin";

export default (function MutationPayloadQueryPlugin(builder) {
  builder.hook(
    "GraphQLObjectType:fields",
    (
      fields: {},
      build: {| ...Build, ...BuildExtensionQuery |},
      context
    ): {} => {
      const { $$isQuery, extend, getTypeByName, inflection } = build;
      const {
        scope: { isMutationPayload },
        Self,
      } = context;
      if (!isMutationPayload) {
        return fields;
      }
      const Query = getTypeByName(inflection.builtin("Query"));
      return extend(
        fields,
        {
          query: {
            description: build.wrapDescription(
              "Our root query field type. Allows us to run any query from our mutation payload.",
              "field"
            ),
            type: Query,
            resolve() {
              return $$isQuery;
            },
          },
        },
        `Adding 'query' field to mutation payload ${Self.name}`
      );
    },
    ["MutationPayloadQuery"]
  );
}: Plugin);