// @flow
import type { Plugin } from "graphile-build";

export default (function PgOrderByPrimaryKeyPlugin(builder) {
  builder.hook(
    "GraphQLEnumType:values",
    (values, build, context) => {
      const { extend, inflection } = build;
      const {
        scope: { isPgRowSortEnum, pgIntrospection: table },
      } = context;

      if (!isPgRowSortEnum || !table || table.kind !== "class") {
        return values;
      }
      const primaryKeyConstraint = table.primaryKeyConstraint;
      if (!primaryKeyConstraint) {
        return values;
      }
      const primaryKeys = primaryKeyConstraint.keyAttributes;

      return extend(
        values,
        {
          [inflection.builtin("PRIMARY_KEY_ASC")]: {
            value: {
              alias: "primary_key_asc",
              specs: primaryKeys.map(key => [key.name, true]),
              unique: true,
            },
          },
          [inflection.builtin("PRIMARY_KEY_DESC")]: {
            value: {
              alias: "primary_key_desc",
              specs: primaryKeys.map(key => [key.name, false]),
              unique: true,
            },
          },
        },
        `Adding primary key asc/desc sort to table '${table.name}'`
      );
    },
    ["PgOrderByPrimaryKey"]
  );
}: Plugin);