// Code.gs — Google Apps Script Web App
// Deploy as: Web app, Execute as "Me", Who has access: "Anyone"

// ============================================
// CONFIGURATION — change these two, then create a NEW deployment version
// ============================================
var SECRET_KEY = '5f5bd4c1751f7582f870954da60cafe2'; // e.g. output of: openssl rand -hex 16
var ALLOWED_EMAIL = 'justiceawudi@outlook.com'; // must match "Login Email" in extension Settings

function doPost(e) {
  try {
    var data = JSON.parse(e.postData.contents);

    if (!data.key || data.key !== SECRET_KEY) {
      Logger.log('Unauthorized request - invalid key');
      return ContentService.createTextOutput(
        JSON.stringify({ error: 'Unauthorized' }),
      ).setMimeType(ContentService.MimeType.JSON);
    }

    if (data.email !== ALLOWED_EMAIL) {
      Logger.log('Unauthorized request - invalid email: ' + data.email);
      return ContentService.createTextOutput(
        JSON.stringify({ error: 'Unauthorized email' }),
      ).setMimeType(ContentService.MimeType.JSON);
    }

    if (data.action === 'pollForLoginLink') {
      var result = pollForMagicLink(data.requestId);
      return ContentService.createTextOutput(
        JSON.stringify(result),
      ).setMimeType(ContentService.MimeType.JSON);
    }

    return ContentService.createTextOutput(
      JSON.stringify({ error: 'Unknown action' }),
    ).setMimeType(ContentService.MimeType.JSON);
  } catch (err) {
    Logger.log('Error in doPost: ' + err.message);
    return ContentService.createTextOutput(
      JSON.stringify({ error: err.message }),
    ).setMimeType(ContentService.MimeType.JSON);
  }
}

// ============================================
// Poll for magic login link.
//
// No "to:" filter — the email is sent to your Outlook address and
// lands in Gmail via a forwarding rule, so its To/Delivered-To headers
// may still reference Outlook rather than Gmail. from + subject +
// newer_than + is:unread is specific enough since this only ever
// searches your own mailbox.
// ============================================
function pollForMagicLink(requestId) {
  var maxAttempts = 4;
  var pollInterval = 15000;

  Logger.log('[' + requestId + '] Starting poll for login link...');

  for (var attempt = 1; attempt <= maxAttempts; attempt++) {
    Logger.log('[' + requestId + '] Attempt ' + attempt + '/' + maxAttempts);

    var searchQuery =
      'from:talent.andela.com subject:"Andela Login Link" newer_than:5m is:unread';
    var threads = GmailApp.search(searchQuery, 0, 5);

    Logger.log(
      '[' + requestId + '] Found ' + threads.length + ' matching threads',
    );

    if (threads.length > 0) {
      var allMessages = [];
      for (var i = 0; i < threads.length; i++) {
        var messages = threads[i].getMessages();
        for (var j = 0; j < messages.length; j++) allMessages.push(messages[j]);
      }

      allMessages.sort(function (a, b) {
        return b.getDate().getTime() - a.getDate().getTime();
      });

      var latestMessage = allMessages[0];
      var body = latestMessage.getBody();

      Logger.log(
        '[' + requestId + '] Processing email from: ' + latestMessage.getDate(),
      );

      var accessAccountPattern =
        /<a\s+[^>]*href=["']([^"']+)["'][^>]*>\s*Access account\s*<\/a>/i;
      var match = body.match(accessAccountPattern);

      if (match && match[1]) {
        var link = match[1]
          .replace(/&amp;/g, '&')
          .replace(/&#x3D;/g, '=')
          .replace(/&#61;/g, '=')
          .replace(/&#x26;/g, '&');

        Logger.log('[' + requestId + '] Found Access account link: ' + link);
        latestMessage.markRead();

        return {
          success: true,
          loginLink: link,
          emailDate: latestMessage.getDate().toISOString(),
          attempt: attempt,
        };
      }

      Logger.log(
        '[' + requestId + '] Email found but no Access account link detected',
      );
    }

    if (attempt < maxAttempts) {
      Logger.log('[' + requestId + '] Waiting ' + pollInterval / 1000 + 's...');
      Utilities.sleep(pollInterval);
    }
  }

  Logger.log(
    '[' +
      requestId +
      '] No login link found after ' +
      maxAttempts +
      ' attempts',
  );
  return {
    success: false,
    error: 'No login link found within timeout',
    attempts: maxAttempts,
  };
}

// ============================================
// Debug helpers — run manually from the Apps Script editor's function
// dropdown, then check the Executions log
// ============================================
function debugLoginEmails() {
  var searchQuery =
    'from:talent.andela.com subject:"Andela Login Link" newer_than:7d';
  var threads = GmailApp.search(searchQuery, 0, 5);
  Logger.log('Found ' + threads.length + ' emails');

  for (var i = 0; i < threads.length; i++) {
    var messages = threads[i].getMessages();
    for (var j = 0; j < messages.length; j++) {
      var msg = messages[j];
      Logger.log('---');
      Logger.log('Subject: ' + msg.getSubject());
      Logger.log('From: ' + msg.getFrom());
      Logger.log('To: ' + msg.getTo());
      Logger.log('Date: ' + msg.getDate());

      var body = msg.getBody();
      var pattern =
        /<a\s+[^>]*href=["']([^"']+)["'][^>]*>\s*Access account\s*<\/a>/i;
      var match = body.match(pattern);
      if (match) {
        Logger.log('Link found: ' + match[1].substring(0, 100));
      } else {
        Logger.log('Access account link not found');
      }
    }
  }
}

function testExtraction() {
  var result = pollForMagicLink('test-' + Date.now());
  Logger.log(JSON.stringify(result, null, 2));
}