import { db, type StoredRow } from "../db/fcmTokens.js";
import { errorMessage, formatElapsedMs } from "../util/formatElapsed.js";
import { maskToken } from "../util/maskToken.js";
import { messaging } from "./firebase.js";

const MS_PRODUCTION = 23 * 60 * 60 * 1000;
const MS_TEST = 10 * 60 * 1000;

export function notifyThresholdMs(testMode?: boolean): number {
  return testMode === true ? MS_TEST : MS_PRODUCTION;
}

/** Epoch ms when the device may receive another push (diagnostics only). */
export function computeNextEligibleAt(row: {
  lastNotifiedAt?: number;
  testMode?: boolean;
}): number {
  const threshold = notifyThresholdMs(row.testMode);
  if (row.lastNotifiedAt === undefined) {
    return Date.now();
  }
  return row.lastNotifiedAt + threshold;
}

function lastNotifiedMs(row: StoredRow | undefined): number | undefined {
  const v = row?.lastNotifiedAt;
  if (v === undefined) return undefined;
  if (typeof v === "number") return Number.isNaN(v) ? undefined : v;
  return undefined;
}

function stringifyData(
  payload: Record<string, unknown>
): Record<string, string> {
  const out: Record<string, string> = {};
  for (const [k, v] of Object.entries(payload)) {
    out[k] = v === undefined || v === null ? "" : String(v);
  }
  return out;
}

/**
 * Sends an FCM data message if the token is outside the dedupe window
 * (23h production, 10m test).
 */
export async function sendPushToDevice(
  fcmToken: string,
  payload: Record<string, unknown> = {}
): Promise<"sent" | "skipped" | "failed"> {
  const suffix = maskToken(fcmToken);
  const row = await db.getByFcmToken(fcmToken);
  const now = Date.now();
  const last = lastNotifiedMs(row);

  if (
    last !== undefined &&
    now - last < notifyThresholdMs(row?.testMode)
  ) {
    return "skipped";
  }

  const sendStarted = Date.now();
  console.log("[Push] Send attempt, token suffix:", suffix);

  try {
    const data: Record<string, string> = {
      ...stringifyData(payload),
      type: "WAKEUP_PING",
    };

    await messaging.send({
      token: fcmToken,
      apns: {
        headers: {
          "apns-push-type": "background",
          "apns-priority": "5",
        },
        payload: {
          aps: {
            contentAvailable: true,
          },
        },
      },
      data,
    });

    const persisted = await db.getByFcmToken(fcmToken);
    if (persisted !== undefined) {
      await db.update(persisted.id, { lastNotifiedAt: Date.now() });
    }
    console.log(
      "[Push] Send completed in",
      formatElapsedMs(Date.now() - sendStarted) + ",",
      "token suffix:",
      suffix
    );
    return "sent";
  } catch (err) {
    console.error(
      "[Push] Send failed in",
      formatElapsedMs(Date.now() - sendStarted) + ",",
      "token suffix:",
      suffix + ":",
      errorMessage(err)
    );
    return "failed";
  }
}