const admin = require("firebase-admin");

module.exports = async (req, res) => {
  const { conference, partyName, partyPin, userName, uid } = JSON.parse(
    req.body
  );
  // GET ROOM PIN
  const [exists, roomPin, conferencePending, partyConference] = await admin
    .firestore()
    .collection("rooms")
    .doc(partyName)
    .get()
    .then((roomSnap) => {
      const data = roomSnap.exists ? roomSnap.data() : {};
      return [
        roomSnap.exists,
        data.pin,
        data.conferencePending,
        data.conference,
      ];
    });
  // CHECK IF ROOM EXISTS
  if (exists === true) {
    if (roomPin) {
      // CHECK FOR CORRECT PIN
      if (roomPin === partyPin) {
        if (conferencePending) {
          if (conferencePending === uid) {
            // UPDATE CONFERENCE DETAILS
            await admin
              .firestore()
              .collection("rooms")
              .doc(partyName)
              .update({ conference })
              .catch((err) =>
                res.status(500).send({
                  message: "Unable to update the call details",
                  error: err,
                })
              );
            // REMOVE PENDING STATUS
            await admin
              .firestore()
              .collection("rooms")
              .doc(partyName)
              .update({
                conferencePending: admin.firestore.FieldValue.delete(),
              })
              .catch((err) =>
                console.error("Failed to remove pending status", err)
              );
            // ADD SYSTEM MESSAGE
            await admin
              .firestore()
              .collection("rooms")
              .doc(partyName)
              .collection("messages")
              .add({
                uid: "<system>",
                name: "",
                text: `${userName} started the call, everyone can join now.`,
                time: new Date(),
              })
              .catch((err) =>
                console.error("Failed to add update conference message", err)
              );
            res.status(200).send({ message: "Started the conference" });
          } else {
            res.status(409).send({
              message: "Looks like someone is already starting a call",
            });
          }
        } else if (partyConference) {
          res.status(409).send({
            message: "Call already exists",
            conference: partyConference,
          });
        }
      } else {
        // WRONG ROOM PIN
        res.status(401).send({ message: "Wrong party pin, try rejoining" });
      }
    }
  } else {
    // ROOM DOESN'T EXIST
    res.status(404).send({ message: "Party Not Found" });
  }
  return;
};