import { Group, GroupFieldType, NestableFieldTypes, NestedGroup } from "@prismicio/types-internal/lib/customtypes"
import { either } from "fp-ts"
import { pipe } from "fp-ts/lib/function"
import * as t from "io-ts"

import { Definition, isFieldDef, WithKey } from "../utils"
import { NestableDef } from "./nestable/NestableDef"

export const NestedGroupDef = createGroupDef(NestedGroup, NestableDef)
export const GroupDef = createGroupDef(Group, t.union([NestableDef, NestedGroupDef]))

const GroupDefType = "Group"

function createGroupDef<
	GroupCodec extends typeof Group | typeof NestedGroup,
	FieldsDefA extends WithKey<Definition<NestableFieldTypes | typeof GroupFieldType>>,
	FieldsDefO,
>(groupCodec: GroupCodec, fieldsDef: t.Type<FieldsDefA, FieldsDefO>) {
	return new t.Type<WithKey<t.TypeOf<GroupCodec>>>(
		"GroupDef",
		(u: unknown): u is WithKey<t.TypeOf<GroupCodec>> => isFieldDef(u) && groupCodec.is(u.def),
		(u: unknown) => {
			const codec = t.strict({
				name: t.string,
				fields: t.array(fieldsDef),
			})

			return pipe(
				codec.decode(u),
				either.map(
					({ name, fields }): WithKey<t.TypeOf<GroupCodec>> => ({
						key: name,
						def: {
							type: GroupDefType,
							config: {
								fields: fields.reduce((acc, field) => ({ ...acc, [field.key]: field.def }), {}),
							},
						},
					}),
				),
			)
		},
		(n) => n,
	)
}