function sendMessageToBackground(message) {
  return new Promise(function(resolve, reject) {
    chrome.runtime.sendMessage(message, function(response) {
      if (chrome.runtime.lastError) {
        reject(new Error(chrome.runtime.lastError.message));
        return;
      }
      resolve(response || null);
    });
  });
}

function setMessage(text, isError) {
  var message = document.getElementById('message');
  if (!message) return;
  message.textContent = text || '';
  message.style.color = isError ? '#ff8585' : '#8892a4';
}

var lastGoodCloudStats = null;
var lastGoodSyncStatus = null;
var syncProgressTimer = null;
var lastServerHealthy = null;

function wait(ms) {
  return new Promise(function(resolve) {
    setTimeout(resolve, ms);
  });
}

function setSyncProgress(text) {
  var el = document.getElementById('syncProgressText');
  if (!el) return;
  el.textContent = text || '';
}

function startSyncProgress(prefix) {
  var startedAt = Date.now();
  var dots = 0;
  if (syncProgressTimer) {
    clearInterval(syncProgressTimer);
  }
  setSyncProgress((prefix || '正在同步') + ' 0s');
  syncProgressTimer = setInterval(function() {
    dots = (dots + 1) % 4;
    var suffix = new Array(dots + 1).join('.');
    var elapsed = Math.max(0, Math.floor((Date.now() - startedAt) / 1000));
    setSyncProgress((prefix || '正在同步') + suffix + ' ' + elapsed + 's');
  }, 500);
}

function stopSyncProgress(text) {
  if (syncProgressTimer) {
    clearInterval(syncProgressTimer);
    syncProgressTimer = null;
  }
  setSyncProgress(text || '');
}

function updateStatus(status) {
  if (status && status.authenticated !== undefined) {
    lastGoodSyncStatus = status;
  }
  var accountDot = document.getElementById('accountDot');
  var accountText = document.getElementById('accountText');
  var email = document.getElementById('syncEmail');
  var loggedOut = document.getElementById('authLoggedOut');
  var loggedIn = document.getElementById('authLoggedIn');
  var loggedInEmail = document.getElementById('loggedInEmail');
  var healthy = !!(status && status.color === 'green');
  var authenticated = !!(status && status.authenticated);
  if (accountDot) accountDot.classList.toggle('ok', healthy);
  if (accountText) accountText.textContent = status && (status.accountText || status.text) ? (status.accountText || status.text) : '账号状态未知';
  if (email) email.textContent = status && status.email ? ('账号：' + status.email) : '';
  if (loggedOut) loggedOut.classList.toggle('hidden', authenticated);
  if (loggedIn) loggedIn.classList.toggle('hidden', !authenticated);
  if (loggedInEmail) loggedInEmail.textContent = status && status.email ? ('当前账号：' + status.email) : '当前账号：未知';
}

function updateServerStatus(ok, text) {
  var serverDot = document.getElementById('serverDot');
  var serverText = document.getElementById('serverText');
  lastServerHealthy = !!ok;
  if (serverDot) serverDot.classList.toggle('ok', !!ok);
  if (serverText) serverText.textContent = text || (ok ? '服务器状态正常' : '服务器状态异常');
}

function formatDateTime(value) {
  if (!value) return '暂无';
  try {
    var date = new Date(value);
    if (Number.isNaN(date.getTime())) return String(value);
    return date.toLocaleString('zh-CN');
  } catch (error) {
    return String(value);
  }
}

function renderCloudStats(stats) {
  var summary = document.getElementById('cloudStatsSummary');
  var latest = document.getElementById('cloudStatsLatest');
  var tables = document.getElementById('cloudStatsTables');
  if (!summary || !latest || !tables) return;
  if (!stats || !stats.ok) {
    if (lastGoodCloudStats && lastGoodCloudStats.ok) {
      updateServerStatus(true, '服务器状态正常（展示最近一次成功数据）');
      summary.textContent = '云端状态暂时刷新失败，显示最近一次成功数据';
      latest.textContent = '最近成功更新：线程 ' + formatDateTime(lastGoodCloudStats.latest.threads) + ' ｜ 范围 ' + formatDateTime(lastGoodCloudStats.latest.coverages) + ' ｜ 页缓存 ' + formatDateTime(lastGoodCloudStats.latest.pages);
      tables.textContent = '上次空间占用：' + (Array.isArray(lastGoodCloudStats.tables) ? lastGoodCloudStats.tables.map(function(table) {
        return table.tableName + ' ' + table.sizeMb + 'MB';
      }).join(' ｜ ') : '暂无');
      return;
    }
    updateServerStatus(false, '服务器状态暂时不可读');
    summary.textContent = '暂时无法读取云端状态';
    latest.textContent = '';
    tables.textContent = '';
    return;
  }
  updateServerStatus(true, '服务器状态正常');
  lastGoodCloudStats = stats;
  summary.textContent = '帖子索引 ' + stats.counts.threads + ' 条（含磁力 ' + (stats.counts.magnetThreads || 0) + ' 条）/ 页缓存 ' + stats.counts.pages + ' 条 / 范围缓存 ' + stats.counts.coverages + ' 条 / 用户 ' + stats.counts.users + ' 个 / 保险柜 ' + stats.counts.vaultItems + ' 条';
  latest.textContent = '最近更新：线程 ' + formatDateTime(stats.latest.threads) + ' ｜ 范围 ' + formatDateTime(stats.latest.coverages) + ' ｜ 页缓存 ' + formatDateTime(stats.latest.pages);
  tables.textContent = '空间占用：' + (Array.isArray(stats.tables) ? stats.tables.map(function(table) {
    return table.tableName + ' ' + table.sizeMb + 'MB';
  }).join(' ｜ ') : '暂无');
}

function formatBytes(bytes) {
  var value = Number(bytes || 0);
  if (!Number.isFinite(value) || value <= 0) return '0 B';
  if (value < 1024) return value + ' B';
  if (value < 1024 * 1024) return (value / 1024).toFixed(1) + ' KB';
  if (value < 1024 * 1024 * 1024) return (value / 1024 / 1024).toFixed(2) + ' MB';
  return (value / 1024 / 1024 / 1024).toFixed(2) + ' GB';
}

function renderLocalStats(stats) {
  var summary = document.getElementById('localStatsSummary');
  var storage = document.getElementById('localStatsStorage');
  var meta = document.getElementById('localStatsMeta');
  if (!summary || !storage || !meta) return;
  if (!stats || !stats.ok) {
    summary.textContent = '暂时无法读取本地状态';
    storage.textContent = '';
    meta.textContent = '';
    return;
  }
  summary.textContent = '帖子索引 ' + stats.counts.threads + ' 条（含磁力 ' + (stats.counts.magnetThreads || 0) + ' 条）/ 页缓存 ' + stats.counts.pages + ' 条 / 范围缓存 ' + stats.counts.coverages + ' 条 / 收藏 ' + stats.counts.favorites + ' 条 / 历史 ' + stats.counts.history + ' 条';
  storage.textContent = '本地存储占用：' + formatBytes(stats.storage.usage) + ' / ' + formatBytes(stats.storage.quota);
  meta.textContent = '上传抑制元数据：线程 ' + stats.counts.uploadMetaThreads + ' 条 ｜ 范围 ' + stats.counts.uploadMetaCoverages + ' 条 ｜ 页 ' + stats.counts.uploadMetaPages + ' 条';
}

async function refreshStatus() {
  try {
    var response = await sendMessageToBackground({ action: 'cloudGetSyncStatus' });
    if (response && response.ok !== false) {
      updateStatus(response || { color: 'red', text: '状态未知', authenticated: false });
      return;
    }
    if (lastGoodSyncStatus) {
      updateStatus(lastGoodSyncStatus);
      setMessage('云同步状态暂时刷新失败，显示最近一次成功状态', true);
      return;
    }
    updateStatus({ color: 'red', text: '云同步异常', authenticated: false, email: '' });
  } catch (error) {
    if (lastGoodSyncStatus) {
      updateStatus(lastGoodSyncStatus);
      setMessage('云同步状态暂时刷新失败，显示最近一次成功状态', true);
      return;
    }
    updateStatus({ color: 'red', text: '云同步异常', authenticated: false, email: '' });
    setMessage('状态获取失败：' + error.message, true);
  }
}

async function refreshCloudStats() {
  var attempts = 0;
  var response = null;
  var error = null;
  for (attempts = 0; attempts < 3; attempts++) {
    try {
      response = await sendMessageToBackground({ action: 'cloudGetCacheStats' });
      if (response && response.ok) {
        renderCloudStats(response);
        return;
      }
    } catch (err) {
      error = err;
    }
    await wait(500 * (attempts + 1));
  }
  renderCloudStats(null);
  if (error) {
    setMessage('云端状态暂时刷新失败，稍后会自动重试', true);
  }
}

async function refreshLocalStats() {
  try {
    var response = await sendMessageToBackground({ action: 'localGetCacheStats' });
    renderLocalStats(response);
  } catch (error) {
    renderLocalStats(null);
  }
}

async function submitAuth(action) {
  var emailInput = document.getElementById('emailInput');
  var passwordInput = document.getElementById('passwordInput');
  var email = emailInput ? emailInput.value.trim() : '';
  var password = passwordInput ? passwordInput.value : '';
  if (!email || !password) {
    setMessage('请输入邮箱和密码', true);
    return;
  }
  setMessage(action === 'cloudRegister' ? '正在注册...' : '正在登录...', false);
  try {
    var response = await sendMessageToBackground({ action: action, email: email, password: password });
    if (!response || !response.ok) {
      setMessage((action === 'cloudRegister' ? '注册失败：' : '登录失败：') + (response && response.error ? response.error : '未知错误'), true);
      return;
    }
    if (passwordInput) passwordInput.value = '';
    updateStatus(response.status || { color: 'green', text: '云同步正常', authenticated: true, email: email });
    setMessage(action === 'cloudRegister' ? '注册成功，云同步已开启' : '登录成功，云同步已开启', false);
  } catch (error) {
    setMessage((action === 'cloudRegister' ? '注册失败：' : '登录失败：') + error.message, true);
  }
}

async function syncNow() {
  setMessage('', false);
  startSyncProgress('正在同步本地缓存到云端');
  try {
    await sendMessageToBackground({ action: 'cloudBackfillLocalCache', force: true });
    stopSyncProgress('已提交同步任务，正在刷新状态...');
    await wait(1200);
    startSyncProgress('正在刷新云端状态');
    await refreshStatus();
    await refreshCloudStats();
    await refreshLocalStats();
    stopSyncProgress('同步完成');
    setMessage('已触发云端回填', false);
  } catch (error) {
    stopSyncProgress('同步失败');
    setMessage('同步失败：' + error.message, true);
  }
}

async function logout() {
  try {
    await sendMessageToBackground({ action: 'cloudLogout' });
    await refreshStatus();
    setMessage('已退出登录', false);
  } catch (error) {
    setMessage('退出失败：' + error.message, true);
  }
}

function openExternalUrl(url) {
  chrome.tabs.create({ url: url });
}

document.addEventListener('DOMContentLoaded', function() {
  document.getElementById('loginBtn').addEventListener('click', function() { submitAuth('cloudLogin'); });
  document.getElementById('registerBtn').addEventListener('click', function() { submitAuth('cloudRegister'); });
  document.getElementById('syncNowBtn').addEventListener('click', syncNow);
  document.getElementById('logoutBtn').addEventListener('click', logout);
  document.getElementById('downloadNode2Btn').addEventListener('click', function() { openExternalUrl('http://7.haory.cn/x/x72/qBittorrent_5.1.4_x64_setup.exe'); });
  document.getElementById('downloadOfficialBtn').addEventListener('click', function() { openExternalUrl('https://sourceforge.net/projects/qbittorrent/files/qbittorrent-win32/qbittorrent-5.1.4/qbittorrent_5.1.4_x64_setup.exe/download'); });
  document.getElementById('downloadMotrixBtn').addEventListener('click', function() { openExternalUrl('http://7.haory.cn/x/x72/Motrix-Setup-1.8.19.exe'); });
  refreshStatus();
  refreshCloudStats();
  refreshLocalStats();
});