// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
import type { NextApiRequest, NextApiResponse } from "next";
import { app } from "@/firebase";
import {
  getFirestore,
  collection,
  getDocs,
  setDoc,
  doc,
  query,
  where,
} from "firebase/firestore";
import { withIronSessionApiRoute } from "iron-session/next";
import { sessionOptions } from "@/lib/session";
import { Group } from "@/interfaces/user";
import { v4 } from "uuid";
import { updateExpiryDateOnGroup } from "@/utils/groups.be";

const db = getFirestore(app);

export default withIronSessionApiRoute(handler, sessionOptions);

async function handler(req: NextApiRequest, res: NextApiResponse) {
  if (!req.session.user) {
    res.status(401).json({ ok: false });
    return;
  }

  if (req.method === "GET") await get(req, res);
  if (req.method === "POST") await post(req, res);
}

const getGroupsForUser = async (admin: string, participant: string) => {
  try {
    const queryConstraints = [
      ...(admin ? [where("admin", "==", admin)] : []),
      ...(participant
        ? [where("participants", "array-contains", participant)]
        : []),
    ];
    const snapshot = await getDocs(
      queryConstraints.length > 0
        ? query(collection(db, "groups"), ...queryConstraints)
        : collection(db, "groups")
    );
    const groups = snapshot.docs.map((doc) => ({
      id: doc.id,
      ...doc.data(),
    })) as Group[];

    return groups;
  } catch (e) {
    console.error(e);
    return [];
  }
};
async function get(req: NextApiRequest, res: NextApiResponse) {
  const { admin, participant } = req.query as {
    admin: string;
    participant: string;
  };

  if (req.session?.user?.type === "mastercorporate") {
    try {
      const masterCorporateGroups = await getGroupsForUser(admin, participant);
      const corporatesFromMaster = masterCorporateGroups
        .filter((g) => g.name === "Corporate")
        .flatMap((g) => g.participants);

      if (corporatesFromMaster.length === 0) {
        res.status(200).json([]);
        return;
      }
      Promise.all(
        corporatesFromMaster.map((c) => getGroupsForUser(c, participant))
      )
        .then((groups) => {
          res.status(200).json([...masterCorporateGroups, ...groups.flat()]);
          return;
        })
        .catch((e) => {
          console.error(e);
          res.status(500).json({ ok: false });
          return;
        });
    } catch (e) {
      console.error(e);
      res.status(500).json({ ok: false });
      return;
    }
    return;
  }

  try {
    const groups = await getGroupsForUser(admin, participant);
    res.status(200).json(groups);
  } catch (e) {
    console.error(e);
    res.status(500).json({ ok: false });
  }
}

async function post(req: NextApiRequest, res: NextApiResponse) {
  const body = req.body as Group;

  await Promise.all(
    body.participants.map(
      async (p) => await updateExpiryDateOnGroup(p, body.admin)
    )
  );

  await setDoc(doc(db, "groups", v4()), {
    name: body.name,
    admin: body.admin,
    participants: body.participants,
  });
  res.status(200).json({ ok: true });
}