// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
import type { NextApiRequest, NextApiResponse } from "next";
import client from "@/lib/mongodb";
import { withIronSessionApiRoute } from "iron-session/next";
import { sessionOptions } from "@/lib/session";
import { flatten, map } from "lodash";
import { AccessType, Exam } from "@/interfaces/exam";
import { MODULE_ARRAY } from "@/utils/moduleUtils";
import { requestUser } from "../../../utils/api";
import { mapBy } from "../../../utils";

const db = client.db(process.env.MONGODB_DB);

export default withIronSessionApiRoute(handler, sessionOptions);

async function handler(req: NextApiRequest, res: NextApiResponse) {
	if (req.method === "GET") return await GET(req, res);

	res.status(404).json({ ok: false });
}

async function GET(req: NextApiRequest, res: NextApiResponse) {
	if (!req.session.user) {
		res.status(401).json({ ok: false });
		return;
	}
	const user = await requestUser(req, res)
	if (!user)
		return res.status(401).json({ ok: false, reason: "You must be logged in!" })
	const isAdmin = ["admin", "developer"].includes(user.type)
	const { entities = [] } = req.query as { access?: AccessType, entities?: string[] | string };
	let entitiesToFetch = Array.isArray(entities) ? entities : entities ? [entities] : []

	if (!isAdmin) {
		const userEntitiesIDs = mapBy(user.entities || [], 'id')
		entitiesToFetch = entities ? entitiesToFetch.filter((entity): entity is string => entity ? userEntitiesIDs.includes(entity) : false) : userEntitiesIDs
		if ((entitiesToFetch.length ?? 0) === 0) {
			res.status(200).json([])
			return
		}
	}

	const moduleExamsPromises = MODULE_ARRAY.map(async (module) => {
		const snapshot = await db.collection(module).find<Exam>({
			isDiagnostic: false, ...(isAdmin && (entitiesToFetch.length ?? 0) === 0 ? {
			} : {
				entity: { $in: entitiesToFetch }
			})
		}).toArray();

		return snapshot.map((doc) => ({
			...doc,
			module,
		}));
	});

	const moduleExams = await Promise.all(moduleExamsPromises);
	res.status(200).json(flatten(moduleExams));
}