import * as prismicT from "@prismicio/types";
import * as RTE from "fp-ts/ReaderTaskEither";
import { identity, pipe } from "fp-ts/function";

import { dotPath } from "../lib/dotPath";
import { reportInfo } from "../lib/reportInfo";

import { Dependencies, FieldConfigCreator } from "../types";

/**
 * Builds a GraphQL field configuration object for a Custom Type field with an
 * unknown type. Because the type is unknown, a `JSON` field type is used as a
 * fallback type. The resulting configuration object can be used in a GraphQL type.
 *
 * Use of this function will be reported to the user's Gatsby log. This informs
 * the user that the field will not act like other fields since its type is
 * unknown. This should only happen if a new Prismic field type is introduced
 * before this plugin supports it.
 *
 * This function registers a typepath for the field.
 *
 * @param path - Path to the field.
 * @param schema - Schema definition for the field.
 *
 * @returns GraphQL field configuration object.
 */
export const buildUnknownFieldConfig: FieldConfigCreator = (
	path: string[],
	schema: prismicT.CustomTypeModelField,
) =>
	pipe(
		RTE.ask<Dependencies>(),
		RTE.chainFirst(() =>
			reportInfo(
				`An unknown field type "${schema.type}" was found at ${dotPath(
					path,
				)}. A generic JSON type will be used. You can manually override the type using Gatsby's createSchemaCustomization API in your site's gatsby-node.js.`,
			),
		),
		RTE.map(() => ({
			type: "JSON",
			resolve: identity,
		})),
	);