/*
private_reminders.json example:
[
  {
    "user": "user id",
    "tz": "Etc/UTC",
    "hour": 0,
    "message": "it midnight"
  }
]
*/

const timer = require("../lib/timer");
const fs = require("fs");
const {resolve} = require("path");

if (!fs.existsSync(resolve(__dirname, "..", "..", "private_reminders.json")))
  return;

const tzFormatterCache = {};
const dmCache = {};

const reminderData = require(resolve(
  __dirname,
  "..",
  "..",
  "private_reminders.json"
));

hf.database.run(
  "CREATE TABLE IF NOT EXISTS private_reminders (user STRING NOT NULL PRIMARY KEY, last_run STRING NOT NULL) WITHOUT ROWID"
);

function setLastRun(id, date) {
  return new Promise((resolve, reject) => {
    hf.database.run(
      "REPLACE INTO private_reminders VALUES ($key,$value)",
      {
        $value: date,
        $key: id,
      },
      (err) => {
        if (err == null) {
          resolve(true);
        } else {
          reject(err);
        }
      }
    );
  });
}

function getLastRun(id) {
  return new Promise((resolve, reject) => {
    hf.database.get(
      "SELECT last_run FROM private_reminders WHERE user = $key",
      {
        $key: id,
      },
      (err, row) => {
        if (err == null) {
          resolve(row?.value);
        } else {
          reject(err);
        }
      }
    );
  });
}

timer.add(
  "private_reminders",
  async () => {
    for (const data of reminderData) {
      if (!tzFormatterCache[data.tz]) {
        tzFormatterCache[data.tz] = Intl.DateTimeFormat("en-US", {
          dateStyle: "short",
          timeStyle: "short",
          hour12: false,
          timeZone: data.tz,
        });
      }

      if (!dmCache[data.user]) {
        dmCache[data.user] = await hf.bot.getDMChannel(data.user);
      }

      const [date, time] = tzFormatterCache[data.tz]
        .format(Date.now())
        .split(", ");
      let [hour, minutes] = time.split(":");
      hour = parseInt(hour);
      minutes = parseInt(minutes);
      const lastRan = await getLastRun(data.user);

      if (date != lastRan && hour == data.hour && minutes == 0) {
        dmCache[data.user].createMessage(":alarm_clock: " + data.message);
        await setLastRun(data.user, date);
      }
    }
  },
  1000
);