const express = require('express');
const { remote } = require('webdriverio');

const APPIUM_HOST = process.env.APPIUM_HOST || '127.0.0.1';
const APPIUM_PORT = parseInt(process.env.APPIUM_PORT || '4723', 10);
const PORT = parseInt(process.env.PORT || '3010', 10);

const app = express();
app.use(express.json({ limit: '10mb' }));

let _driver = null;

async function getDriver() {
  if (_driver) {
    try {
      await _driver.getSession();
      return _driver;
    } catch {
      try { await _driver.deleteSession(); } catch {}
      _driver = null;
    }
  }
  _driver = await remote({
    hostname: APPIUM_HOST,
    port: APPIUM_PORT,
    capabilities: {
      platformName: 'Android',
      'appium:automationName': 'UiAutomator2',
      'appium:deviceName': 'Android',
      'appium:noReset': true,
      'appium:newCommandTimeout': 120,
    },
    logLevel: 'warn',
  });
  return _driver;
}

async function retry(fn, attempts = 3, delay = 2000) {
  for (let i = 0; i < attempts; i++) {
    try {
      return await fn();
    } catch (e) {
      if (i === attempts - 1) throw e;
      await new Promise((r) => setTimeout(r, delay));
    }
  }
}

function uia(selector) {
  return `android=new UiSelector().${selector}`;
}

function find(d, selector, timeout = 5000) {
  return d.$(selector).waitForExist({ timeout }).then(() => d.$(selector), () => null);
}

async function ensureWhatsApp(d) {
  const pkg = await d.getCurrentPackage();
  if (pkg !== 'com.whatsapp') {
    await d.startActivity('com.whatsapp', 'com.whatsapp.HomeActivity');
    await d.pause(2000);
  }
}

async function goHome(d) {
  await retry(async () => {
    await d.startActivity('com.whatsapp', 'com.whatsapp.HomeActivity');
    await d.pause(1500);
  }, 2, 1000);
}

async function openChat(d, query) {
  await goHome(d);

  const searchBar = await find(
    d,
    uia('resourceId("com.whatsapp:id/search_bar_inner_layout")'),
    3000
  );
  if (!searchBar) throw new Error('Could not find search bar');
  await searchBar.click();
  await d.pause(2000);

  const searchInput = await find(d, uia('resourceId("com.whatsapp:id/search_input")'), 3000);
  if (!searchInput) throw new Error('Could not find search input');
  await searchInput.clearValue();
  await d.pause(300);
  await searchInput.setValue(query);
  await d.pause(2000);

  // Find and click the matching chat row
  const chats = await d.$$(uia('resourceId("com.whatsapp:id/contact_row_container")'));
  for (const row of chats) {
    const nameEl = await row.$(
      uia('resourceId("com.whatsapp:id/conversations_row_contact_name")')
    );
    const name = await nameEl.getText().catch(() => '');
    if (name.toLowerCase().includes(query.toLowerCase())) {
      await row.click();
      await d.pause(1500);
      return;
    }
  }
  // If no match by name, try clicking first result
  if (chats.length > 0) {
    await chats[0].click();
    await d.pause(1500);
    return;
  }
  throw new Error(`No chat found for "${query}"`);
}

// ── Debug ─────────────────────────────────────────────────────────



// ── Endpoints ─────────────────────────────────────────────────────

app.get('/health', async (_req, res) => {
  try {
    const d = await getDriver();
    const session = await d.getSession();
    res.json({ status: 'ok', sessionId: d.sessionId });
  } catch (e) {
    res.status(503).json({ status: 'error', message: e.message });
  }
});

app.get('/client/getChats/:session', async (req, res) => {
  try {
    const d = await getDriver();
    await ensureWhatsApp(d);
    await goHome(d);

    const rows = await d.$$(uia('resourceId("com.whatsapp:id/contact_row_container")'));
    const chats = [];

    for (const row of rows) {
      try {
        const nameEl = await row.$(
          uia('resourceId("com.whatsapp:id/conversations_row_contact_name")')
        );
        const name = await nameEl.getText();

        const msgEl = await row.$(uia('resourceId("com.whatsapp:id/single_msg_tv")'));
        let lastMessage = '';
        if (await msgEl.isExisting()) {
          lastMessage = await msgEl.getText();
        } else {
          const msgFromEl = await row.$(uia('resourceId("com.whatsapp:id/msg_from_tv")'));
          if (await msgFromEl.isExisting()) lastMessage = await msgFromEl.getText();
        }

        const timeEl = await row.$(
          uia('resourceId("com.whatsapp:id/conversations_row_date")')
        );
        const timestamp = (await timeEl.isExisting()) ? await timeEl.getText() : '';

        const unreadEl = await row.$(
          uia('resourceId("com.whatsapp:id/conversations_row_unread_indicator")')
        );
        let unread = 0;
        if (await unreadEl.isExisting()) {
          const desc = await unreadEl.getAttribute('content-desc');
          const m = desc ? desc.match(/(\d+)/) : null;
          if (m) unread = parseInt(m[1], 10);
        }

        chats.push({ name, lastMessage, timestamp, unread });
      } catch {}
    }

    res.json({ chats });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

app.post('/chat/fetchMessages/:session', async (req, res) => {
  try {
    const { chatId } = req.body;
    if (!chatId) return res.status(400).json({ error: 'chatId required' });

    const d = await getDriver();
    await ensureWhatsApp(d);
    const query = chatId.replace(/@[cg]\.us$/, '');
    await openChat(d, query);
    await d.pause(2000);

    const layoutEls = await d.$$(uia('resourceId("com.whatsapp:id/main_layout")'));
    const messages = [];

    for (const layout of layoutEls) {
      try {
        const textEl = await layout.$(uia('resourceId("com.whatsapp:id/message_text")'));
        const dateEl = await layout.$(
          uia('resourceId("com.whatsapp:id/date")')
        );
        if (await textEl.isExisting()) {
          messages.push({
            text: await textEl.getText(),
            timestamp: (await dateEl.isExisting()) ? await dateEl.getText() : '',
          });
        }
      } catch {}
    }

    messages.reverse();
    goHome(d).catch(() => {});
    res.json({ messages });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

app.post('/client/sendMessage/:session', async (req, res) => {
  try {
    const { chatId, content } = req.body;
    if (!chatId) return res.status(400).json({ error: 'chatId required' });
    if (!content) return res.status(400).json({ error: 'content required' });

    const d = await getDriver();
    await ensureWhatsApp(d);
    const query = chatId.replace(/@[cg]\.us$/, '');
    await openChat(d, query);

    const input = await find(d, uia('resourceId("com.whatsapp:id/entry")'), 5000);
    if (!input) throw new Error('Could not find message input');

    await input.setValue(content);
    await d.pause(500);

    let sendBtn = await find(d, uia('resourceId("com.whatsapp:id/send")'), 3000);
    if (!sendBtn) {
      sendBtn = await find(d, uia('descriptionContains("Send")'), 2000);
    }
    if (!sendBtn) throw new Error('Could not find send button');
    await sendBtn.click();

    await d.pause(1000);
    goHome(d).catch(() => {});
    res.json({ status: 'sent', content });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

app.listen(PORT, '0.0.0.0', () => {
  console.log(`wa-appium-api listening on http://0.0.0.0:${PORT}`);
  console.log(`  Appium server: ${APPIUM_HOST}:${APPIUM_PORT}`);
});