#!/usr/bin/env node
/**
 * WhatsApp Presence Monitor — Baileys-based
 * Logs online/offline status of a target number to presence-log.json
 *
 * Setup:
 *   npm init -y
 *   npm install @whiskeysockets/baileys @hapi/boom pino qrcode-terminal
 *
 * Run:
 *   node monitor.js
 *
 * Then scan the QR code with your WhatsApp (Settings → Linked Devices)
 * The log file is written to ./presence-log.json
 * Import that file in the Analyse tab to build the behavioral profile.
 */

const { default: makeWASocket, useMultiFileAuthState, fetchLatestBaileysVersion, DisconnectReason, makeCacheableSignalKeyStore } = require("@whiskeysockets/baileys");
const { Boom } = require("@hapi/boom");
const pino = require("pino");
const fs = require("fs");

const TARGET = "+XXXXXXXXXXX";   // E.164 format e.g. +33612345678
const LOG_FILE = "./presence-log.json";
const INTERVAL_MS = 20_000;  // poll every 20 seconds (reduce to 10s for tighter resolution)

const jid = TARGET.replace("+", "") + "@s.whatsapp.net";

let log = fs.existsSync(LOG_FILE)
  ? JSON.parse(fs.readFileSync(LOG_FILE, "utf8"))
  : [];

function save(entry) {
  log.push(entry);
  fs.writeFileSync(LOG_FILE, JSON.stringify(log, null, 2));
}

function fmt(ms) {
  if (ms < 60000) return ms / 1000 + "s";
  if (ms < 3600000) return (ms / 60000).toFixed(1) + "m";
  return (ms / 3600000).toFixed(2) + "h";
}

async function start() {
  const { state, saveCreds } = await useMultiFileAuthState("./wa-session");
  const { version } = await fetchLatestBaileysVersion();

  const sock = makeWASocket({
    version,
    auth: {
      creds: state.creds,
      keys: makeCacheableSignalKeyStore(state.keys, pino({ level: "silent" })),
    },
    logger: pino({ level: "silent" }),
    printQRInTerminal: true,
    markOnlineOnConnect: false,
    generateHighQualityLinkPreview: false,
  });

  sock.ev.on("creds.update", saveCreds);

  let lastStatus = null;
  let lastOnlineAt = null;

  sock.ev.on("connection.update", async ({ connection, lastDisconnect, qr }) => {
    if (connection === "close") {
      const reason = new Boom(lastDisconnect?.error)?.output?.statusCode;
      const shouldReconnect = reason !== DisconnectReason.loggedOut;
      console.log("[!] Connection closed, reason:", reason, "— reconnecting:", shouldReconnect);
      if (shouldReconnect) setTimeout(start, 5_000);
      return;
    }

    if (connection === "open") {
      console.log("[+] Connected to WhatsApp");
      console.log("[*] Subscribing to presence:", TARGET);

      try {
        await sock.presenceSubscribe(jid);
        console.log("[+] Presence subscription active");
        console.log("[*] Monitoring started. Ctrl+C to stop. Log:", LOG_FILE);
      } catch (e) {
        console.error("[!] Presence subscribe failed:", e.message);
        console.log("[~] Falling back to polling via profile query every", fmt(INTERVAL_MS));
        // Fallback polling loop
        setInterval(async () => {
          try {
            const [result] = await sock.onWhatsApp(jid);
            const online = result?.exists ?? false;
            const status = online ? "online" : "offline";
            if (status !== lastStatus) {
              const entry = { ts: Date.now(), status };
              save(entry);
              if (status === "online") lastOnlineAt = Date.now();
              if (status === "offline" && lastOnlineAt) {
                const dur = Date.now() - lastOnlineAt;
                console.log(`[${new Date().toISOString()}] offline (session: ${fmt(dur)})`);
              } else {
                console.log(`[${new Date().toISOString()}] ${status}`);
              }
              lastStatus = status;
            }
          } catch { /* connection issue */ }
        }, INTERVAL_MS);
      }
    }
  });

  sock.ev.on("presence.update", ({ id, presences }) => {
    if (id !== jid) return;
    const p = presences[jid];
    if (!p) return;

    // available / unavailable / composing / recording
    const isOnline = p.lastKnownPresence === "available" || p.lastKnownPresence === "composing" || p.lastKnownPresence === "recording";
    const status = isOnline ? "online" : "offline";

    if (status !== lastStatus) {
      const entry = { ts: Date.now(), status, raw: p.lastKnownPresence };
      save(entry);

      if (status === "online") {
        lastOnlineAt = Date.now();
        console.log(`[${new Date().toISOString()}] ONLINE`);
      } else {
        const dur = lastOnlineAt ? Date.now() - lastOnlineAt : null;
        console.log(`[${new Date().toISOString()}] offline${dur ? " (session: " + fmt(dur) + ")" : ""}`);
        lastOnlineAt = null;
      }

      lastStatus = status;
    }
  });
}

start().catch(console.error);

[
  { "ts": 1710500000000, "status": "online" },
  { "ts": 1710500120000, "status": "offline" },
  { "ts": 1710506400000, "status": "online" },
  ...
]