{% extends "base.html" %}
{% block title %}AI Chat{% endblock %}
{% block page_title %}AI 对话{% endblock %}

{% block topbar_extra %}
<button onclick="toggleChatSidebar()" aria-label="会话列表" style="
  background: rgba(255,255,255,0.15); border: none; color: white;
  padding: 4px 10px; border-radius: 6px; font-size: 13px; cursor: pointer;
  display: flex; align-items: center; gap: 4px;
">&equiv; 对话</button>
{% endblock %}

{% block body %}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/github-dark.min.css">
<style>
/* ── Chat-specific overrides (dark theme) ── */
/* Fix for foldable/unfolded: 100dvh handles dynamic viewport height */
.main { height: 100dvh; height: calc(100dvh - 48px); padding-top: 0; overflow: hidden; background: #343541; }

/* Chat layout: sidebar + main area */
.chat-layout { display: flex; height: 100%; }

/* ── Session sidebar ── */
.chat-sidebar { width: 260px; background: #202123; color: white; display: flex;
  flex-direction: column; flex-shrink: 0; position: relative; z-index: 1; }
.chat-sidebar-header { padding: 12px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.chat-sidebar-header .brand { font-size: 15px; font-weight: bold; color: white; margin-bottom: 8px; }
.chat-search { padding: 8px 12px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.chat-search input { width: 100%; box-sizing: border-box; padding: 8px 10px; border: 1px solid rgba(255,255,255,0.15); border-radius: 6px; background: #2d2d2f; color: white; font-size: 13px; }
.chat-search input::placeholder { color: #666; }
.conv-sort { padding: 8px 12px; border-bottom: 1px solid rgba(255,255,255,0.1); display: flex; gap: 8px; }
.conv-sort select { flex: 1; padding: 6px 8px; border: 1px solid rgba(255,255,255,0.15); border-radius: 6px; background: #2d2d2f; color: white; font-size: 12px; }
.new-chat-btn { width: 100%; padding: 8px 12px; border: 1px solid rgba(255,255,255,0.2);
  border-radius: 6px; background: transparent; color: white; font-size: 13px;
  cursor: pointer; text-align: left; transition: .15s; position: relative; z-index: 2;
  -webkit-tap-highlight-color: transparent; }
.new-chat-btn:hover { background: rgba(255,255,255,0.1); }
.new-chat-btn:active { background: rgba(255,255,255,0.2); }

.conv-list { flex: 1; overflow-y: auto; padding: 4px 8px; }
.conv-item { padding: 10px 12px; border-radius: 6px; cursor: pointer; margin-bottom: 2px;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; transition: .15s; -webkit-tap-highlight-color: transparent; }
.conv-item:hover { background: rgba(255,255,255,0.08); }
.conv-item.active { background: rgba(255,255,255,0.15); }
.conv-item .title { flex: 1; overflow: hidden; text-overflow: ellipsis;
  white-space: nowrap; color: #ececec; }
.conv-item .time { font-size: 11px; color: #888; margin-left: 8px; flex-shrink: 0; }
.conv-item .delete-btn { display: none; color: #888; margin-left: 6px; font-size: 14px;
  cursor: pointer; }
.conv-item:hover .delete-btn { display: inline; }
.conv-item .delete-btn:hover { color: #e74c3c; }

.chat-sidebar-footer { padding: 12px; border-top: 1px solid rgba(255,255,255,0.1); }
.chat-sidebar-footer a { color: #888; text-decoration: none; font-size: 12px; }
.chat-sidebar-footer a:hover { color: white; }

/* ── Sidebar toggle button ── (always visible) */
.chat-toggle-btn { display: flex; align-items: center; justify-content: center;
  background: none; border: none; color: white; font-size: 18px; cursor: pointer;
  padding: 4px 8px; border-radius: 4px; -webkit-tap-highlight-color: transparent; }
.chat-toggle-btn:hover { background: rgba(255,255,255,0.1); }
.chat-toggle-btn:active { background: rgba(255,255,255,0.2); }
.chat-sidebar-overlay { display: none; position: fixed; top: 48px; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5); z-index: 50; }

/* ── Main chat area ── */
.chat-main { flex: 1; display: flex; flex-direction: column; min-width: 0;
  position: relative; z-index: 1; }
.chat-main-header { padding: 8px 16px; border-bottom: 1px solid rgba(255,255,255,0.1);
  color: white; font-size: 14px; display: flex; align-items: center; gap: 8px; }
.chat-main-header .conv-title { font-weight: bold; }

/* ── Message list ── */
.msg-list { flex: 1; overflow-y: auto; padding: 16px 20px;
  display: flex; flex-direction: column; gap: 4px; }

/* ... (msg-row, avatar, bubble styles unchanged) ... */
.msg-row { display: flex; margin-bottom: 4px; align-items: flex-start; gap: 8px; }
.msg-row.user { justify-content: flex-end; }
.msg-row.assistant { justify-content: flex-start; }

.msg-avatar { width: 30px; height: 30px; border-radius: 4px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: bold; color: white; user-select: none; }
.msg-avatar.ai { background: #19c37d; }
.msg-avatar.user-av { background: #3498db; }

.msg-bubble { padding: 10px 14px; border-radius: 8px; font-size: 14px;
  line-height: 1.55; word-break: break-word; max-width: 70%; }
.msg-row.user .msg-bubble { background: #2563eb; color: white; }
.msg-row.assistant .msg-bubble { background: #444654; color: #ececec; }

.msg-time { font-size: 10px; color: #888; margin-top: 2px; padding: 0 2px; }
.msg-row.user .msg-time { text-align: right; }

/* Empty state */
.empty-state { flex: 1; display: flex; align-items: center; justify-content: center;
  color: #888; font-size: 15px; }

/* Typing indicator */
.typing-indicator { display: flex; align-items: center; gap: 8px;
  padding: 10px 14px; color: #888; font-size: 13px; }
.typing-dots { display: flex; gap: 3px; }
.typing-dots span { width: 6px; height: 6px; background: #888; border-radius: 50%;
  animation: typingBounce 1.4s infinite; }
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes typingBounce { 0%,60%,100%{transform:translateY(0);} 30%{transform:translateY(-6px);} }

/* Input area — with safe-area for foldables */
.chat-input-area { padding: 12px 16px;
  padding-bottom: max(12px, env(safe-area-inset-bottom, 12px));
  border-top: 1px solid rgba(255,255,255,0.1); display: flex; gap: 8px;
  align-items: flex-end; background: #40414f; position: relative; z-index: 1; }
.chat-input-area textarea { flex: 1; background: #40414f;
  border: 1px solid rgba(255,255,255,0.15); border-radius: 8px;
  color: white; font-size: 14px; padding: 10px 14px; resize: none;
  min-height: 44px; max-height: 150px; font-family: inherit;
  line-height: 1.4; outline: none; transition: border-color .15s;
  -webkit-tap-highlight-color: transparent; }
.chat-input-area textarea:focus { border-color: #2563eb; }
.chat-input-area textarea::placeholder { color: #888; }
.chat-input-area button { width: 40px; height: 40px; border: none; border-radius: 8px;
  background: #2563eb; color: white; font-size: 16px; cursor: pointer;
  flex-shrink: 0; display: flex; align-items: center; justify-content: center;
  transition: background .15s; -webkit-tap-highlight-color: transparent; }
.chat-input-area button:hover { background: #1d4ed8; }
.chat-input-area button:active { background: #1e40af; }
.chat-input-area button:disabled { background: #555; cursor: not-allowed; }

/* Markdown-ish */
.msg-bubble pre { background: rgba(0,0,0,0.2); padding: 8px; border-radius: 4px;
  overflow-x: auto; font-size: 13px; margin: 6px 0; }
.msg-bubble code { font-size: 12px; }
.msg-bubble p { margin: 4px 0; }

/* ── Responsive ── */
/* ≤600px only (phone/folded): sidebar becomes a slide-out drawer */
@media (max-width: 600px) {
  .chat-sidebar { position: fixed; top: 48px; left: 0; bottom: 0; z-index: 51;
    transform: translateX(-100%); transition: transform 0.25s ease; }
  .chat-sidebar.open { transform: translateX(0); }
  .chat-sidebar-overlay.show { display: block; }
}
/* >600px (incl. foldable dual-screen): sidebar visible by default, toggle hides it */
@media (min-width: 601px) {
  .chat-sidebar.collapsed { display: none; }
}
</style>

<div class="chat-layout">
  <!-- Session sidebar overlay (mobile) -->
  <div class="chat-sidebar-overlay" id="chatSidebarOverlay" onclick="closeChatSidebar()"></div>

  <!-- Session sidebar -->
  <div class="chat-sidebar" id="chatSidebar">
    <div class="chat-sidebar-header">
      <div class="brand">🧠 AI Chat</div>
      <button class="new-chat-btn" onclick="newConversation()">+ 新建对话</button>
    </div>
    <div class="chat-search">
      <input type="text" id="searchInput" placeholder="搜索对话..." oninput="renderConversations()">
    </div>
    <div class="conv-sort">
      <select id="sortBy" onchange="renderConversations()">
        <option value="time">按时间↓</option>
        <option value="title">按标题</option>
      </select>
    </div>
    <div class="conv-list" id="convList"></div>
    <div class="chat-sidebar-footer">
      <a href="/">← 返回首页</a>
    </div>
  </div>

  <!-- Main chat area -->
  <div class="chat-main">
    <div class="chat-main-header">
      <button class="chat-toggle-btn" onclick="toggleChatSidebar()" aria-label="会话列表">📋</button>
      <span class="conv-title" id="currentConvTitle">选择一个对话</span>
      <select id="agentSelect" onchange="onAgentChange()" style="margin-left:auto;font-size:12px;padding:3px 8px;border:1px solid #ddd;border-radius:6px;background:white;cursor:pointer;">
        <option value="default">🤖 default</option>
        <option value="planning">📋 planning</option>
        <option value="loop-code">💻 loop-code</option>
        <option value="qa">🧪 qa</option>
      </select>
    </div>
    <div class="msg-list" id="msgList">
      <div class="empty-state" id="emptyState">选择一个对话开始聊天</div>
    </div>
    <div class="chat-input-area">
      <textarea id="msgInput" rows="1" placeholder="输入消息..."
        onkeydown="handleKeyDown(event)"></textarea>
      <button id="sendBtn" onclick="sendMessage()">▶</button>
    </div>
  </div>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
<script>
// ── Sidebar toggle ── works at all widths
function toggleChatSidebar() {
  var sidebar = document.getElementById('chatSidebar');
  var overlay = document.getElementById('chatSidebarOverlay');
  // ≤600px: slide-out drawer mode
  if (window.innerWidth <= 600) {
    if (sidebar.classList.contains('open')) {
      closeChatSidebar();
    } else {
      sidebar.classList.add('open');
      overlay.classList.add('show');
    }
  } else {
    // >600px: collapse/expand in-place (toggle visibility)
    sidebar.classList.toggle('collapsed');
  }
}
function closeChatSidebar() {
  var sidebar = document.getElementById('chatSidebar');
  var overlay = document.getElementById('chatSidebarOverlay');
  sidebar.classList.remove('open');
  overlay.classList.remove('show');
}

function onAgentChange() {
  var sel = document.getElementById('agentSelect');
  console.log('Agent switched to:', sel.value);
}

// ── State ──
var currentConvId = null;
var isStreaming = false;

// ── Conversation Management ──

var allConversations = [];

function loadConversations() {
  try {
    var r = fetch('/api/conversations');
    r.then(function(res){ return res.json(); }).then(function(d){
      if (!d.ok) return;
      allConversations = d.data || [];
      renderConversations();
    });
  } catch(e) { console.error('loadConversations:', e); }
}

// ── Inline Rename ──
function startRename(span, convId) {
  if (span.getAttribute('contenteditable') === 'true') return;
  var oldTitle = span.textContent;
  span.setAttribute('contenteditable', 'true');
  span.focus();
  // Select all text
  var range = document.createRange();
  range.selectNodeContents(span);
  var sel = window.getSelection();
  sel.removeAllRanges();
  sel.addRange(range);
  
  function finish() {
    span.removeAttribute('contenteditable');
    var newTitle = span.textContent.trim();
    if (!newTitle || newTitle === oldTitle) {
      span.textContent = oldTitle;
      return;
    }
    // Save via API
    fetch('/api/conversations/' + convId, {
      method: 'PUT',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({title: newTitle})
    }).then(function(r) { return r.json(); }).then(function(d) {
      if (d.ok) {
        span.textContent = newTitle;
        if (currentConvId === convId) {
          document.getElementById('currentConvTitle').textContent = newTitle;
        }
      } else {
        span.textContent = oldTitle;
      }
    }).catch(function() { span.textContent = oldTitle; });
  }
  
  span.onblur = finish;
  span.onkeydown = function(e) {
    if (e.key === 'Enter') { e.preventDefault(); finish(); }
    if (e.key === 'Escape') { span.textContent = oldTitle; span.onblur = null; span.removeAttribute('contenteditable'); }
  };
}

function renderConversations() {
  var el = document.getElementById('convList');
  var q = (document.getElementById('searchInput').value || '').trim().toLowerCase();
  var sb = document.getElementById('sortBy').value;
  var convs = allConversations.slice();
  if (q) {
    convs = convs.filter(function(c) {
      return (c.title || '新对话').toLowerCase().indexOf(q) >= 0;
    });
  }
  if (sb === 'title') convs.sort(function(a,b){return (a.title||'').localeCompare(b.title||'')});
  else convs.sort(function(a,b){return (b.updated_at||'').localeCompare(a.updated_at||'')});

  if (!convs || convs.length === 0) {
    el.innerHTML = '<div style="padding:12px;color:#888;font-size:13px;">暂无对话</div>';
    return;
  }
  el.innerHTML = convs.map(function(c) {
    var title = c.title || '新对话';
    var time = formatTime(c.updated_at);
    var active = c.id === currentConvId ? ' active' : '';
    return '<div class="conv-item' + active + '" onclick="selectConversation(' + c.id + ')" data-cid="' + c.id + '">' +
      '<span class="title" ondblclick="startRename(this,' + c.id + ')">' + escapeHtml(title) + '</span>' +
      '<span class="time">' + time + '</span>' +
      '<span class="delete-btn" onclick="event.stopPropagation();deleteConversation(' + c.id + ')" title="删除">&times;</span>' +
    '</div>';
  }).join('');
}

function selectConversation(id) {
  // Update active state in DOM directly (no full reload to avoid race conditions)
  document.querySelectorAll('.conv-item').forEach(function(item) {
    item.classList.remove('active');
    if (parseInt(item.getAttribute('data-cid')) === id) {
      item.classList.add('active');
    }
  });
  
  currentConvId = id;
  var titleEl = document.querySelector('[data-cid="' + id + '"] .title');
  document.getElementById('currentConvTitle').textContent =
    (titleEl ? titleEl.textContent : '') || '对话';
  document.getElementById('emptyState').style.display = 'none';
  document.getElementById('sendBtn').disabled = false;
  loadMessages(id);    // load history
  // Update URL to /ai-chat/<id> so refresh/share keeps the session
  history.replaceState(null, '', '/ai-chat/' + id);
  // Close sidebar on mobile after selection
  if (window.innerWidth <= 600) {
    closeChatSidebar();
  }
}

async function newConversation() {
  // Don't POST immediately — defer creation until first message is sent.
  // ChatGPT behavior: click "New Chat" → blank page → type → send → create session.
  currentConvId = null;
  document.getElementById('currentConvTitle').textContent = '新对话';
  document.getElementById('emptyState').style.display = 'none';
  document.getElementById('msgList').innerHTML =
    '<div class="empty-state">输入消息开始新对话</div>';
  // Clear input + disable sendBtn (input handler will enable when user types)
  document.getElementById('msgInput').value = '';
  document.getElementById('msgInput').style.height = 'auto';
  document.getElementById('sendBtn').disabled = true;
  document.getElementById('msgInput').focus();
  // Update URL to /chat (no id)
  history.replaceState(null, '', '/chat');
  if (window.innerWidth <= 600) {
    closeChatSidebar();
  }
}

async function deleteConversation(id) {
  if (!confirm('确定删除这个对话？')) return;
  try {
    await fetch('/api/conversations/' + id, {method: 'DELETE'});
    if (currentConvId === id) {
      currentConvId = null;
      document.getElementById('currentConvTitle').textContent = '选择一个对话';
      document.getElementById('emptyState').style.display = 'flex';
      document.getElementById('msgList').innerHTML =
        '<div class="empty-state" id="emptyState">选择一个对话开始聊天</div>';
      document.getElementById('sendBtn').disabled = true;
    }
    loadConversations();
  } catch(e) { console.error('deleteConversation:', e); }
}

// ── Message Loading ──

async function loadMessages(convId) {
  if (!convId) return;
  try {
    var r = await fetch('/api/conversations/' + convId + '/messages');
    var d = await r.json();
    var list = document.getElementById('msgList');
    if (!d.ok || !d.data || d.data.length === 0) {
      list.innerHTML = '<div class="empty-state">开始对话吧</div>';
      document.getElementById('emptyState').style.display = 'none';
      return;
    }
    list.innerHTML = d.data.map(function(m) { return renderMsg(m); }).join('');
    // Apply syntax highlighting to code blocks
    if (typeof hljs !== 'undefined') {
      list.querySelectorAll('pre code').forEach(function(block) { hljs.highlightElement(block); });
    }
    scrollToBottom();
  } catch(e) { console.error('loadMessages:', e); }
}

function renderMsg(m) {
  var role = m.role;
  var content = escapeHtml(m.content || '');
  var time = formatTime(m.created_at);
  var formatted = content
    .replace(/```(\w+)?\n?([\s\S]*?)```/g, '<pre><code>$2</code></pre>')
    .replace(/\n/g, '<br>');

  if (role === 'user') {
    return '<div class="msg-row user" data-msgid="' + m.id + '">' +
      '<div style="display:flex;flex-direction:column;align-items:flex-end;">' +
      '<div class="msg-bubble" ondblclick="editMessage(this,' + m.id + ')" title="双击编辑">' + formatted + '</div>' +
      '<div class="msg-time">' + time + '</div>' +
      '</div>' +
      '<div class="msg-avatar user-av">U</div>' +
    '</div>';
  } else {
    return '<div class="msg-row assistant" data-msgid="' + m.id + '">' +
      '<div class="msg-avatar ai">AI</div>' +
      '<div style="display:flex;flex-direction:column;align-items:flex-start;">' +
      '<div class="msg-bubble">' + formatted + '</div>' +
      '<div class="msg-time">' + time +
      ' <span class="regen-btn" onclick="regenerateReply(' + m.id + ')" title="重新生成" style="cursor:pointer;color:#888;margin-left:6px;">⟳</span>' +
      '</div>' +
      '</div>' +
    '</div>';
  }
}

// ── Message Edit ──

function editMessage(el, msgId) {
  if (isStreaming) return;
  if (el.getAttribute('contenteditable') === 'true') return;
  var oldContent = el.textContent;
  el.setAttribute('contenteditable', 'true');
  el.focus();
  el.style.outline = '2px solid #2563eb';
  el.style.borderRadius = '4px';

  function finish(save) {
    el.removeAttribute('contenteditable');
    el.style.outline = '';
    if (!save) {
      el.textContent = oldContent;
      return;
    }
    var newContent = el.textContent.trim();
    if (!newContent || newContent === oldContent) {
      el.textContent = oldContent;
      return;
    }
    // Save via API
    fetch('/api/conversations/' + currentConvId + '/messages/' + msgId, {
      method: 'PUT',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify({content: newContent})
    }).then(function(r) { return r.json(); }).then(function(d) {
      if (d.ok) {
        el.textContent = newContent;
        // Auto-regenerate: delete old AI reply and get new one
        regenerateReply(null);
      } else {
        el.textContent = oldContent;
        alert('编辑失败: ' + (d.error || ''));
      }
    }).catch(function() { el.textContent = oldContent; });
  }

  el.onblur = function() { finish(true); };
  el.onkeydown = function(e) {
    if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); finish(true); }
    if (e.key === 'Escape') { finish(false); }
  };
}

// ── Regenerate Reply ──

function regenerateReply(msgId) {
  if (isStreaming) return;
  isStreaming = true;
  document.getElementById('sendBtn').disabled = true;

  // Remove the last AI bubble visually
  var msgList = document.getElementById('msgList');
  var aiRows = msgList.querySelectorAll('.msg-row.assistant');
  if (aiRows.length > 0) {
    aiRows[aiRows.length - 1].remove();
  }

  // Add typing indicator
  var typingId = 'typing-' + Date.now();
  msgList.insertAdjacentHTML('beforeend',
    '<div class="msg-row assistant" id="' + typingId + '">' +
    '<div class="msg-avatar ai">AI</div>' +
    '<div class="typing-indicator">' +
    '<div class="typing-dots"><span></span><span></span><span></span></div>' +
    '重新生成中...' +
    '</div></div>');
  scrollToBottom();

  var es = new EventSource('/api/conversations/' + currentConvId + '/regenerate');
  var aiBubble = null;
  var fullReply = '';

  es.onmessage = function(e) {
    if (e.data === '[DONE]') {
      es.close();
      var typingEl = document.getElementById(typingId);
      if (typingEl) typingEl.remove();
      isStreaming = false;
      document.getElementById('sendBtn').disabled = false;
      document.getElementById('msgInput').focus();
      loadConversations();
      return;
    }
    var typingEl = document.getElementById(typingId);
    if (typingEl && !aiBubble) {
      typingEl.outerHTML = '<div class="msg-row assistant" id="ai-' + typingId + '">' +
        '<div class="msg-avatar ai">AI</div>' +
        '<div class="msg-bubble" id="ai-bubble-' + typingId + '"></div>' +
      '</div>';
      aiBubble = document.getElementById('ai-bubble-' + typingId);
    }
    if (aiBubble) {
      fullReply += e.data;
      aiBubble.innerHTML = escapeHtml(fullReply).replace(/\n/g, '<br>');
      scrollToBottom();
    }
  };

  es.onerror = function() {
    es.close();
    var typingEl = document.getElementById(typingId);
    if (typingEl) typingEl.remove();
    if (!fullReply && aiBubble) {
      aiBubble.textContent = '[连接中断]';
    }
    isStreaming = false;
    document.getElementById('sendBtn').disabled = false;
    loadConversations();
  };
}

// ── Send Message (SSE streaming) ──

function handleKeyDown(e) {
  if (e.key === 'Enter' && !e.shiftKey) {
    e.preventDefault();
    sendMessage();
  }
}

async function sendMessage() {
  if (isStreaming) return;
  var input = document.getElementById('msgInput');
  var message = input.value.trim();
  if (!message) return;

  isStreaming = true;
  document.getElementById('sendBtn').disabled = true;

  // Deferred conversation creation: if no conversation yet, create one now
  if (!currentConvId) {
    try {
      var cr = await fetch('/api/conversations', {
        method: 'POST',
        headers: {'Content-Type': 'application/json'},
        body: JSON.stringify({title: message.slice(0, 30)})
      });
      var cd = await cr.json();
      if (!cd.ok) {
        alert('创建对话失败: ' + (cd.error || ''));
        isStreaming = false;
        document.getElementById('sendBtn').disabled = false;
        return;
      }
      currentConvId = cd.data.id;
      loadConversations();  // refresh sidebar
      // Update URL to /ai-chat/<id> so refresh/share keeps the session
      history.replaceState(null, '', '/ai-chat/' + currentConvId);
    } catch(e) {
      alert('网络错误: ' + e.message);
      isStreaming = false;
      document.getElementById('sendBtn').disabled = false;
      return;
    }
  }

  input.value = '';
  input.style.height = 'auto';

  // Add user message to UI immediately
  var msgList = document.getElementById('msgList');
  document.getElementById('emptyState').style.display = 'none';
  var now = new Date();
  var timeStr = now.toLocaleTimeString([], {hour:'2-digit', minute:'2-digit'});
  msgList.insertAdjacentHTML('beforeend',
    '<div class="msg-row user">' +
    '<div style="display:flex;flex-direction:column;align-items:flex-end;">' +
    '<div class="msg-bubble">' + escapeHtml(message) + '</div>' +
    '<div class="msg-time">' + timeStr + '</div>' +
    '</div>' +
    '<div class="msg-avatar user-av">U</div>' +
    '</div>');

  // Add typing indicator
  var typingId = 'typing-' + Date.now();
  msgList.insertAdjacentHTML('beforeend',
    '<div class="msg-row assistant" id="' + typingId + '">' +
    '<div class="msg-avatar ai">AI</div>' +
    '<div class="typing-indicator">' +
    '<div class="typing-dots"><span></span><span></span><span></span></div>' +
    '思考中...' +
    '</div></div>');
  scrollToBottom();

  // Start SSE stream
  var agent = document.getElementById('agentSelect').value;
  var streamUrl = '/api/conversations/' + currentConvId + '/stream?message=' + encodeURIComponent(message) + '&agent=' + encodeURIComponent(agent);
  var es = new EventSource(streamUrl);
  var aiBubble = null;
  var fullReply = '';

  es.onmessage = function(e) {
    if (e.data === '[DONE]') {
      es.close();
      // Remove typing indicator
      var typingEl = document.getElementById(typingId);
      if (typingEl) typingEl.remove();
      isStreaming = false;
      document.getElementById('sendBtn').disabled = false;
      document.getElementById('msgInput').focus();

      // Reload conversations to update title/timestamp
      loadConversations();
      return;
    }
    // First chunk: replace typing indicator with actual bubble
    var typingEl = document.getElementById(typingId);
    if (typingEl && !aiBubble) {
      typingEl.outerHTML = '<div class="msg-row assistant" id="ai-' + typingId + '">' +
        '<div class="msg-avatar ai">AI</div>' +
        '<div class="msg-bubble" id="ai-bubble-' + typingId + '"></div>' +
      '</div>';
      aiBubble = document.getElementById('ai-bubble-' + typingId);
    }
    if (aiBubble) {
      fullReply += e.data;
      aiBubble.innerHTML = escapeHtml(fullReply).replace(/\n/g, '<br>');
      scrollToBottom();
    }
  };

  es.onerror = function() {
    es.close();
    var typingEl = document.getElementById(typingId);
    if (typingEl) typingEl.remove();
    if (!fullReply && aiBubble) {
      aiBubble.textContent = '[连接中断，请重试]';
    }
    isStreaming = false;
    document.getElementById('sendBtn').disabled = false;
    loadConversations();
  };

  // Auto-resize textarea
  input.style.height = 'auto';
}

// Auto-resize textarea + button state
document.getElementById('msgInput').addEventListener('input', function() {
  this.style.height = 'auto';
  this.style.height = Math.min(this.scrollHeight, 150) + 'px';
  // Enable send button only when there's text and not streaming
  var btn = document.getElementById('sendBtn');
  if (!isStreaming) {
    btn.disabled = !this.value.trim();
  }
});

// ── Utils ──

function scrollToBottom() {
  var list = document.getElementById('msgList');
  setTimeout(function() { list.scrollTop = list.scrollHeight; }, 50);
}

function formatTime(dt) {
  if (!dt) return '';
  var d = new Date(dt);
  var now = new Date();
  var diff = now - d;
  if (diff < 60000) return '刚刚';
  if (diff < 3600000) return Math.floor(diff/60000) + '分钟前';
  if (diff < 86400000) return Math.floor(diff/3600000) + '小时前';
  return d.toLocaleDateString('zh-CN');
}

function escapeHtml(s) {
  var d = document.createElement('div');
  d.textContent = s;
  return d.innerHTML;
}

// Init
loadConversations();
// Start with send button disabled until user types
document.getElementById('sendBtn').disabled = true;

// If Flask passed an initial_conv_id (from /chat/<conv_id>), auto-select it
{% if initial_conv_id is defined and initial_conv_id %}
(function() {
  var targetId = {{ initial_conv_id }};
  // Wait for conversation list to load, then select the target conversation
  var checkInterval = setInterval(function() {
    var item = document.querySelector('[data-cid="' + targetId + '"]');
    if (item) {
      clearInterval(checkInterval);
      selectConversation(targetId);
    }
  }, 100);
  // Safety timeout after 5s
  setTimeout(function() { clearInterval(checkInterval); }, 5000);
})();
{% endif %}
</script>
{% endblock %}