// tplink-session.js — Playwright-based TP-Link ONU session manager
// Uses headless Chromium because TP-Link XX230v GDPR_ENCRYPT requires
// the modem's own JS to handle RSA/AES key exchange natively.

const { chromium } = require('playwright');

const sessions = new Map();
const IDLE_TIMEOUT_MS = 5 * 60 * 1000;
const LOGIN_TIMEOUT_MS = 15 * 1000;
const NAV_TIMEOUT_MS = 20 * 1000;

let browser = null;

async function getBrowser() {
  if (!browser || !browser.isConnected()) {
    browser = await chromium.launch({
      headless: true,
      args: [
        '--no-sandbox', '--disable-setuid-sandbox',
        '--disable-dev-shm-usage', '--disable-gpu',
        '--ignore-certificate-errors', '--disable-web-security',
      ]
    });
    console.log('[modem-bridge] Chromium launched');
  }
  return browser;
}

function resetIdleTimer(ip) {
  const s = sessions.get(ip); if (!s) return;
  clearTimeout(s.idleTimer);
  s.idleTimer = setTimeout(() => {
    console.log(`[modem-bridge] Session expired: ${ip}`);
    closeSession(ip);
  }, IDLE_TIMEOUT_MS);
}

function getSession(ip) {
  const s = sessions.get(ip);
  if (!s || !s.loggedIn) throw new Error(`No active session for ${ip}`);
  s.lastActivity = Date.now();
  resetIdleTimer(ip);
  return s;
}

async function login(ip, user, pass, path = '/superadmin') {
  if (sessions.has(ip)) await closeSession(ip);

  const b = await getBrowser();
  const context = await b.newContext({
    ignoreHTTPSErrors: true,
    viewport: { width: 1280, height: 720 },
    userAgent: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36'
  });

  const page = await context.newPage();
  const url = `https://${ip}${path}`;

  await page.goto(url, { waitUntil: 'networkidle', timeout: NAV_TIMEOUT_MS });
  await page.waitForSelector('#pc-login-password', { timeout: LOGIN_TIMEOUT_MS });

  const hasUsername = await page.evaluate(() => {
    const el = document.getElementById('pc-login-user-div');
    return el && !el.classList.contains('nd');
  });

  if (hasUsername) await page.fill('#pc-login-user', user);
  await page.fill('#pc-login-password', pass);
  await page.waitForTimeout(300);

  const navigationPromise = page.waitForNavigation({
    waitUntil: 'networkidle', timeout: LOGIN_TIMEOUT_MS
  }).catch(() => null);

  await page.click('#pc-login-btn');
  await navigationPromise;
  await page.waitForTimeout(2000);

  // Handle force-logout dialog if another session was active
  const forceLogoutBtn = await page.$('#confirm-yes');
  if (forceLogoutBtn && await forceLogoutBtn.isVisible()) {
    console.log(`[modem-bridge] Force logout dialog for ${ip}, confirming...`);
    const navP2 = page.waitForNavigation({ waitUntil: 'networkidle', timeout: LOGIN_TIMEOUT_MS }).catch(() => null);
    await forceLogoutBtn.click();
    await navP2;
    await page.waitForTimeout(3000);
  }

  const loginResult = await page.evaluate(() => {
    const loginDiv = document.getElementById('pc-login');
    if (loginDiv && !loginDiv.classList.contains('nd')) {
      const errEl = document.querySelector('.errDiv .errText, .errDivP .errTextP');
      return { success: false, error: errEl ? errEl.textContent.trim() : 'Login failed - still on login page' };
    }
    return { success: true, hasDm: typeof $ !== 'undefined' && $ && $.dm && typeof $.dm.get === 'function' };
  });

  if (!loginResult.success) {
    await context.close();
    throw new Error(`Login failed for ${ip}: ${loginResult.error}`);
  }

  const session = {
    ip, context, page,
    loggedIn: true,
    loginTime: Date.now(),
    lastActivity: Date.now(),
    hasDm: loginResult.hasDm
  };

  sessions.set(ip, session);
  resetIdleTimer(ip);

  console.log(`[modem-bridge] Logged in to ${ip} (hasDm: ${loginResult.hasDm})`);
  return { ip, loggedIn: true, loginTime: session.loginTime, hasDm: loginResult.hasDm };
}

async function dmGet(ip, oid, opts = {}) {
  const s = getSession(ip);
  const stack = opts.stack || '0,0,0,0,0,0';
  const attrs = opts.attrs || null;

  return await s.page.evaluate(({ oid, stack, attrs }) => {
    return new Promise((resolve, reject) => {
      if (!$ || !$.dm || !$.dm.get) { reject(new Error('Data manager not available')); return; }

      const req = {
        oid,
        data: { stack },
        callback: {
          success: (data, others) => resolve({ success: true, data, others }),
          fail: (errorcode, others, data) => resolve({ success: false, errorcode, data }),
          error: (status) => reject(new Error('Request error: ' + status))
        }
      };
      if (attrs) req.data.attrs = attrs;

      try { $.dm.get(req); } catch(e) { reject(e); }
      setTimeout(() => reject(new Error('DM request timeout')), 8000);
    });
  }, { oid, stack, attrs });
}

async function cgiRequest(ip, oidPath) {
  const s = getSession(ip);

  return await s.page.evaluate((oidPath) => {
    return new Promise((resolve, reject) => {
      if (!$ || !$.dm || !$.dm.cgi) { reject(new Error('CGI not available')); return; }

      $.dm.cgi({
        oid: oidPath,
        callback: {
          success: (data) => resolve({ success: true, data }),
          fail: (errorcode) => resolve({ success: false, errorcode })
        }
      });
      setTimeout(() => reject(new Error('CGI request timeout')), 8000);
    });
  }, oidPath);
}

async function getStatus(ip) {
  const s = getSession(ip);

  return await s.page.evaluate(() => {
    const status = {};
    try { if (typeof deviceInfo !== 'undefined') status.deviceInfo = deviceInfo; } catch(e) {}
    try { if ($ && $.status) status.cached = $.status; } catch(e) {}
    try {
      status.dom = {};
      document.querySelectorAll('[id*="status"], [id*="info"], [class*="status"]').forEach(el => {
        if (el.textContent.trim().length < 200) status.dom[el.id || el.className] = el.textContent.trim();
      });
    } catch(e) {}
    return status;
  });
}

async function screenshot(ip) {
  const s = getSession(ip);
  return await s.page.screenshot({ type: 'png', fullPage: false });
}

async function wifiDiagnostic(ip) {
  const s = getSession(ip);

  return await s.page.evaluate(() => {
    const start = Date.now();

    // Factory for $.dm query calls — handles both getSubList and get
    function dmQuery(method, oid, extraData) {
      return new Promise((resolve) => {
        if (!$ || !$.dm || !$.dm[method]) { resolve({ oid, error: `${method} not available` }); return; }
        const req = {
          oid,
          callback: {
            success: (data) => resolve({ oid, data }),
            fail: (code) => resolve({ oid, error: code }),
          }
        };
        if (extraData) req.data = extraData;
        $.dm[method](req);
        setTimeout(() => resolve({ oid, error: 'timeout' }), 8000);
      });
    }

    return Promise.allSettled([
      dmQuery('getSubList', 'DEV2_WIFI_RADIO'),
      dmQuery('getSubList', 'DEV2_WIFI_APDEV'),
      dmQuery('getSubList', 'DEV2_WIFI_APDEV_RADIO'),
      dmQuery('getSubList', 'DEV2_WIFI_APDEV_ASSOCDEV'),
      dmQuery('getSubList', 'DEV2_WIFI_DE_STA'),
      dmQuery('getSubList', 'DEV2_WIFI_APDEV_STATS'),
      dmQuery('getSubList', 'DEV2_IP_INTF_V4ADDR'),
      dmQuery('get', 'DEV2_ONLINESTATUS', { stack: '0,0,0,0,0,0' }),
    ]).then(results => {
      const keys = ['radios', 'meshNodes', 'nodeRadios', 'clients', 'clientStats', 'packetStats', 'wanIPs', 'onlineStatus'];
      const out = { fetchedAt: new Date().toISOString(), durationMs: Date.now() - start };
      results.forEach((r, i) => {
        const val = r.status === 'fulfilled' ? r.value : { error: r.reason };
        out[keys[i]] = val.error ? { error: val.error } : val.data;
      });
      return out;
    });
  });
}

async function evaluate(ip, code) {
  const s = getSession(ip);
  return await s.page.evaluate(new Function('return (' + code + ')'));
}

async function getPageContent(ip) {
  const s = getSession(ip);
  return await s.page.content();
}

async function navigate(ip, path) {
  const s = getSession(ip);
  await s.page.goto(`https://${ip}${path}`, { waitUntil: 'networkidle', timeout: NAV_TIMEOUT_MS });
}

async function closeSession(ip) {
  const s = sessions.get(ip);
  if (!s) return;
  clearTimeout(s.idleTimer);
  try { await s.context.close(); }
  catch(e) { console.warn(`[modem-bridge] Error closing session for ${ip}:`, e.message); }
  sessions.delete(ip);
  console.log(`[modem-bridge] Session closed for ${ip}`);
}

async function shutdown() {
  for (const [ip] of sessions) await closeSession(ip);
  if (browser) { await browser.close(); browser = null; }
  console.log('[modem-bridge] Shutdown complete');
}

function listSessions() {
  const result = [];
  for (const [ip, s] of sessions) {
    result.push({
      ip, loggedIn: s.loggedIn, loginTime: s.loginTime,
      lastActivity: s.lastActivity, idleMs: Date.now() - s.lastActivity, hasDm: s.hasDm
    });
  }
  return result;
}

module.exports = {
  login, dmGet, cgiRequest, getStatus, wifiDiagnostic,
  evaluate, screenshot, getPageContent, navigate,
  closeSession, shutdown, listSessions
};