import { db } from "./db/fcmTokens.js";
import { sendPushToDevice } from "./services/pushService.js";
import { errorMessage, formatElapsedMs } from "./util/formatElapsed.js";

let intervalId: ReturnType<typeof setInterval> | undefined;

export function startScheduler(): void {
  if (intervalId !== undefined) return;

  intervalId = setInterval(async () => {
    const passStarted = Date.now();
    console.log("[Scheduler] Pass started");

    try {
      const devices = await db.getAllForScheduler();
      const seenTokens = new Set<string>();
      let checked = 0;
      let sent = 0;
      let skipped = 0;
      let failed = 0;
      let duplicates = 0;

      for (const d of devices) {
        if (seenTokens.has(d.fcmToken)) {
          duplicates++;
          continue;
        }
        seenTokens.add(d.fcmToken);
        checked++;

        const result = await sendPushToDevice(d.fcmToken);
        if (result === "sent") sent++;
        else if (result === "skipped") skipped++;
        else failed++;
      }

      const summaryParts = [
        `Checked ${checked} devices`,
        `sent ${sent} pushes`,
        `skipped ${skipped}`,
      ];
      if (failed > 0) summaryParts.push(`failed ${failed}`);
      if (duplicates > 0) {
        summaryParts.push(`${duplicates} duplicates ignored`);
      }
      console.log("[Scheduler]", summaryParts.join(", "));
      console.log(
        "[Scheduler] Pass completed in",
        formatElapsedMs(Date.now() - passStarted)
      );
    } catch (err) {
      console.error(
        "[Scheduler] Pass failed in",
        formatElapsedMs(Date.now() - passStarted) + ":",
        errorMessage(err)
      );
    }
  }, 5 * 60 * 1000);
}

export function stopScheduler(): void {
  if (intervalId !== undefined) {
    clearInterval(intervalId);
    intervalId = undefined;
  }
}