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

const timeDiff = (ds1, ds2) => {
  const d1 = new Date(ds1);
  const d2 = new Date(ds2);
  var diff = (d2.getTime() - d1.getTime()) / 1000;
  diff /= 60 * 60;
  return Math.abs(Math.round(diff));
};

const cleanUser = async (pT, sT) => {
  var usersToDelete = [];
  await admin
    .auth()
    .listUsers(1000, pT)
    .then(async (listUsersResult) => {
      listUsersResult.users.forEach((userRecord) => {
        if (
          userRecord.uid !== "PTjxbs2rAxMvCD6Pj5P6Z2U6d5A3" &&
          timeDiff(userRecord.metadata.lastRefreshTime, sT) >= 24
        ) {
          usersToDelete.push(userRecord.uid);
        }
      });
      if (listUsersResult.pageToken) {
        const uD = await cleanUser(listUsersResult.pageToken, sT);
        usersToDelete.push(...uD);
      }
      return;
    })
    .catch((error) => {
      console.log("Error listing users:", error);
    });
  return usersToDelete;
};

const batchDeleteUser = async (userList, totalNumber) => {
  setTimeout(async () => {
    const uTDSplice = userList.splice(0, 100);
    if (uTDSplice.length > 0) {
      await admin
        .auth()
        .deleteUsers(uTDSplice)
        .catch((err) =>
          console.error(
            `[ERROR]\tWEBHOOKS/User Clean Up\t# OF USERS ${userList.length} REMAINING,\tERROR:${err}`
          )
        );
      console.info(
        `[DONE]\tWEBHOOKS/User Clean Up\t# OF USERS ${uTDSplice.length}/${userList.length}`
      );
      batchDeleteUser(userList, totalNumber);
    } else {
      console.info(
        `[DONE]\tWEBHOOKS/User Clean Up\tDeleted all ${totalNumber} stale users`
      );
    }
  }, 3000);
};

module.exports = async (req, res) => {
  console.info(`[START]\tWEBHOOKS/User Clean Up`);
  res.status(200).send({ message: "User Clean Up Started" });
  const startedTime = new Date();
  const usersToDelete = await cleanUser(undefined, startedTime);
  console.info(
    `[PROGRESS]\tWEBHOOKS/User Clean Up\t# OF USERS ${usersToDelete.length}`
  );
  batchDeleteUser(usersToDelete, usersToDelete.length);
};