var wbBackend = false;
var wbItems = [];
var wbEditId = null;
var LOCAL_WB_KEY = 'spanish_diary_wordbook';

function wbEsc(s) {
  var div = document.createElement('div');
  div.textContent = s == null ? '' : String(s);
  return div.innerHTML;
}

function wbMsg(text) {
  document.getElementById('wb-msg').textContent = text || '';
}

function loadLocalWords() {
  try {
    wbItems = JSON.parse(localStorage.getItem(LOCAL_WB_KEY) || '[]');
  } catch (e) {
    wbItems = [];
  }
  renderWordbook();
}

function saveLocalWords() {
  localStorage.setItem(LOCAL_WB_KEY, JSON.stringify(wbItems));
}

function loadWords() {
  if (wbBackend) {
    apiGetVocabulary().then(function(items) {
      wbItems = items || [];
      renderWordbook();
    }).catch(function(err) {
      wbMsg(err.message || '加载单词本失败');
    });
  } else {
    loadLocalWords();
  }
}

function getFilteredWords() {
  var keyword = document.getElementById('search-word').value.trim().toLowerCase();
  var category = document.getElementById('filter-category').value;
  var sort = document.getElementById('sort-word').value;
  var filtered = wbItems.filter(function(item) {
    var matchKeyword = !keyword ||
      String(item.word || '').toLowerCase().indexOf(keyword) >= 0 ||
      String(item.english || '').toLowerCase().indexOf(keyword) >= 0 ||
      String(item.chinese || '').toLowerCase().indexOf(keyword) >= 0;
    var matchCategory = !category || String(item.category || '') === category;
    return matchKeyword && matchCategory;
  });
  filtered.sort(function(a, b) {
    if (sort === 'word') return String(a.word || '').localeCompare(String(b.word || ''), 'es');
    if (sort === 'category') {
      var c = String(a.category || '').localeCompare(String(b.category || ''), 'zh-CN');
      if (c !== 0) return c;
      return String(a.word || '').localeCompare(String(b.word || ''), 'es');
    }
    return String(b.created_at || '').localeCompare(String(a.created_at || ''));
  });
  return filtered;
}

function renderWordbook() {
  var categories = {};
  wbItems.forEach(function(item) {
    var cat = String(item.category || '其他').trim() || '其他';
    categories[cat] = (categories[cat] || 0) + 1;
  });
  var filter = document.getElementById('filter-category');
  var current = filter.value;
  var categoryKeys = Object.keys(categories).sort(function(a, b) {
    return a.localeCompare(b, 'zh-CN');
  });
  filter.innerHTML = '<option value="">全部分类</option>' + categoryKeys.map(function(cat) {
    return '<option value="' + wbEsc(cat) + '"' + (cat === current ? ' selected' : '') + '>' +
      wbEsc(cat) + ' (' + categories[cat] + ')</option>';
  }).join('');

  document.getElementById('wb-total').textContent = '共 ' + wbItems.length + ' 个单词';
  document.getElementById('wb-category-count').textContent = categoryKeys.length + ' 个分类';

  var filtered = getFilteredWords();
  var container = document.getElementById('wb-list');
  if (filtered.length === 0) {
    container.innerHTML = '<div class="empty-state">还没有收藏单词，或没有匹配结果</div>';
    return;
  }
  container.innerHTML = filtered.map(function(item) {
    var cat = String(item.category || '其他').trim() || '其他';
    return '<div class="word-card" data-id="' + item.id + '">' +
      '<div class="word-main">' +
        '<span class="word-text">' + wbEsc(item.word) + '</span>' +
        '<span class="word-cat">' + wbEsc(cat) + '</span>' +
      '</div>' +
      '<div class="word-langs">' +
        '<div class="lang-line"><span class="lang-label">ES</span><span class="lang-value">' + wbEsc(item.word) + '</span><button class="speak-word" data-lang="es">🔊</button></div>' +
        '<div class="lang-line"><span class="lang-label">EN</span><span class="lang-value">' + wbEsc(item.english || '-') + '</span><button class="speak-word" data-lang="en">🔊</button></div>' +
        '<div class="lang-line"><span class="lang-label">CN</span><span class="lang-value">' + wbEsc(item.chinese || '-') + '</span><button class="speak-word" data-lang="zh">🔊</button></div>' +
      '</div>' +
      '<div class="word-actions">' +
        '<button class="edit-word">编辑</button>' +
        '<button class="danger delete-word">删除</button>' +
      '</div>' +
    '</div>';
  }).join('');
}

function addWord() {
  var data = {
    word: document.getElementById('add-word').value.trim(),
    english: document.getElementById('add-english').value.trim(),
    chinese: document.getElementById('add-chinese').value.trim(),
    category: document.getElementById('add-category').value.trim()
  };
  if (!data.word) {
    wbMsg('请输入西语单词');
    return;
  }
  var finish = function() {
    document.getElementById('add-word').value = '';
    document.getElementById('add-english').value = '';
    document.getElementById('add-chinese').value = '';
    document.getElementById('add-category').value = '';
    loadWords();
  };
  if (wbBackend) {
    apiAddVocabulary(data).then(finish).catch(function(err) {
      wbMsg(err.message || '添加失败');
    });
  } else {
    data.id = 'local-' + Date.now();
    data.created_at = new Date().toISOString();
    wbItems.unshift(data);
    saveLocalWords();
    finish();
  }
}

function openEdit(id) {
  var item = wbItems.find(function(w) { return String(w.id) === String(id); });
  if (!item) return;
  wbEditId = id;
  document.getElementById('edit-word').value = item.word || '';
  document.getElementById('edit-english').value = item.english || '';
  document.getElementById('edit-chinese').value = item.chinese || '';
  document.getElementById('edit-category').value = item.category || '';
  document.getElementById('edit-overlay').classList.add('show');
}

function closeEdit() {
  wbEditId = null;
  document.getElementById('edit-overlay').classList.remove('show');
}

function saveEdit() {
  if (!wbEditId) return;
  var data = {
    word: document.getElementById('edit-word').value.trim(),
    english: document.getElementById('edit-english').value.trim(),
    chinese: document.getElementById('edit-chinese').value.trim(),
    category: document.getElementById('edit-category').value.trim()
  };
  if (!data.word) {
    wbMsg('请输入西语单词');
    return;
  }
  var finish = function() {
    closeEdit();
    loadWords();
  };
  if (wbBackend) {
    apiUpdateVocabulary(wbEditId, data).then(finish).catch(function(err) {
      wbMsg(err.message || '保存失败');
    });
  } else {
    var idx = wbItems.findIndex(function(w) { return String(w.id) === String(wbEditId); });
    if (idx >= 0) {
      Object.assign(wbItems[idx], data);
      saveLocalWords();
    }
    finish();
  }
}

function deleteWord(id) {
  if (!confirm('确定从单词本中删除该单词吗？')) return;
  var finish = function() {
    loadWords();
  };
  if (wbBackend) {
    apiDeleteVocabulary(id).then(finish).catch(function(err) {
      wbMsg(err.message || '删除失败');
    });
  } else {
    wbItems = wbItems.filter(function(w) { return String(w.id) !== String(id); });
    saveLocalWords();
    finish();
  }
}

document.getElementById('btn-add-word').addEventListener('click', addWord);
document.getElementById('search-word').addEventListener('input', renderWordbook);
document.getElementById('filter-category').addEventListener('change', renderWordbook);
document.getElementById('sort-word').addEventListener('change', renderWordbook);
document.getElementById('edit-cancel').addEventListener('click', closeEdit);
document.getElementById('edit-save').addEventListener('click', saveEdit);

document.getElementById('wb-list').addEventListener('click', function(e) {
  var card = e.target.closest('.word-card');
  if (!card) return;
  var id = card.dataset.id;
  if (e.target.closest('.speak-word')) {
    var item = wbItems.find(function(w) { return String(w.id) === String(id); });
    if (!item) return;
    var lang = e.target.closest('.speak-word').dataset.lang;
    if (lang === 'es') speakText(item.word, 'es');
    else if (lang === 'en') speakText(item.english, 'en');
    else speakText(item.chinese, 'zh');
    return;
  }
  if (e.target.closest('.edit-word')) {
    openEdit(id);
    return;
  }
  if (e.target.closest('.delete-word')) {
    deleteWord(id);
  }
});

apiGetMe().then(function() {
  wbBackend = true;
  loadWords();
}).catch(function(err) {
  if (err && err.status === 401) {
    location.href = 'login.html';
    return;
  }
  wbBackend = false;
  loadWords();
});