import { useState, useEffect, useCallback, useRef } from 'react';
import { Settings2, Zap, Mic, MessageSquare, History, Plus, Film } from 'lucide-react';
import VoicePanel from './components/VoicePanel';
import ChatPanel from './components/ChatPanel';
import SettingsPanel from './components/SettingsPanel';
import { getVoiceConfig } from './services/voiceApi';
import SessionHistoryPanel from './components/SessionHistoryPanel';
import VideoPanel from './components/VideoPanel';

export default function App() {
  const [showSettings, setShowSettings] = useState(false);
  const [showHistory, setShowHistory] = useState(false);
  const [voiceConfig, setVoiceConfig] = useState(null);
  // 'voice' | 'chat'
  const [mode, setMode] = useState('voice');
  // 统一会话 ID（贯穿语音和文字模式，数据库用此 ID 关联所有消息）
  const [currentSessionId, setCurrentSessionId] = useState(null);
  // 语音转文字的交接数据（保留兼容）
  const [handoff, setHandoff] = useState(null);
  // 文字聊天消息（用于切回语音时注入上下文）
  const [chatMessages, setChatMessages] = useState([]);
  const [settings, setSettings] = useState({
    modelVersion: 'O',
    speaker: 'zh_female_vv_jupiter_bigtts',
    enableWebSearch: false,
  });
  // 文字对话引擎: 'coze' (原方舟 HTTP/SSE) | 's2s' (S2S WebSocket, event 501)
  const [textEngine, setTextEngine] = useState(() => {
    try {
      return localStorage.getItem('bigwo_text_engine') || 'coze';
    } catch (_) {
      return 'coze';
    }
  });
  const toggleTextEngine = useCallback(() => {
    setTextEngine((prev) => {
      const next = prev === 'coze' ? 's2s' : 'coze';
      try { localStorage.setItem('bigwo_text_engine', next); } catch (_) {}
      return next;
    });
  }, []);

  useEffect(() => {
    getVoiceConfig()
      .then(setVoiceConfig)
      .catch((err) => console.warn('Failed to load config:', err));
  }, []);

  // 语音通话结束后，无缝切换到文字对话（携带同一个 sessionId）
  const handleVoiceEnd = useCallback((data) => {
    if (data?.sessionId) {
      const sid = data.sessionId;
      setCurrentSessionId(sid);
      setHandoff({
        sessionId: sid,
        subtitles: data.subtitles || [],
      });
      setMode('chat');
      console.log(`[App] Voice→Chat, sessionId=${sid}`);
    }
  }, []);

  // 从文字模式返回语音模式（使用同一个 sessionId，数据库已有完整历史）
  const handleBackToVoice = useCallback(() => {
    console.log(`[App] Chat→Voice, sessionId=${currentSessionId}`);
    setMode('voice');
  }, [currentSessionId]);

  // 切换到文字模式（复用已有 sessionId，没有时新建）
  const handleStartChat = useCallback(() => {
    const sid = currentSessionId || `chat_${Date.now().toString(36)}`;
    setCurrentSessionId(sid);
    setHandoff({
      sessionId: sid,
      subtitles: [],
    });
    setMode('chat');
    console.log(`[App] Switch to chat, sessionId=${sid}`);
  }, [currentSessionId]);

  // 语音会话创建时同步 sessionId 到 App 状态
  const handleSessionCreated = useCallback((sessionId) => {
    if (sessionId && sessionId !== currentSessionId) {
      setCurrentSessionId(sessionId);
      console.log(`[App] Voice session synced: ${sessionId}`);
    }
  }, [currentSessionId]);

  // 新建会话：重置所有状态
  const handleNewSession = useCallback(() => {
    setCurrentSessionId(null);
    setHandoff(null);
    setChatMessages([]);
    setMode('voice');
    console.log('[App] New session created');
  }, []);

  // 从历史记录中选择会话
  const handleSelectSession = useCallback((session) => {
    const sid = session.id;
    setCurrentSessionId(sid);
    setChatMessages([]);
    // 根据会话最后的模式决定打开方式，默认用文字模式查看历史
    setHandoff({
      sessionId: sid,
      subtitles: [],
    });
    setMode('chat');
    console.log(`[App] Selected session: ${sid}, mode: ${session.mode}`);
  }, []);

  return (
    <div className="min-h-screen bg-gradient-to-br from-slate-900 via-slate-800 to-slate-900">
      {/* Header */}
      <header className="border-b border-slate-700/50 bg-slate-900/80 backdrop-blur-sm sticky top-0 z-30">
        <div className="max-w-5xl mx-auto px-3 sm:px-4 h-14 flex items-center justify-between">
          <div className="flex items-center gap-2.5">
            <div className="w-8 h-8 rounded-lg bg-gradient-to-br from-violet-500 to-indigo-600 flex items-center justify-center">
              <Zap className="w-4 h-4 text-white" />
            </div>
            <div>
              <h1 className="text-sm font-semibold text-white leading-tight">
                {mode === 'voice' ? '语音通话' : mode === 'chat' ? '文字对话' : 'AI 视频'}
              </h1>
              <p className="text-[11px] text-slate-400 leading-tight">
                {mode === 'voice'
                  ? '直连 S2S 语音 · ChatTTSText'
                  : mode === 'chat'
                    ? (textEngine === 's2s'
                      ? 'S2S 文字 · event 501 ChatTextQuery'
                      : (handoff?.subtitles?.length > 0
                        ? '语音转接 · 上下文已延续'
                        : '方舟 LLM · Function Calling'))
                    : 'Seedance · AI 视频生成'}
              </p>
            </div>
          </div>
          <div className="flex items-center gap-1.5">
            {/* History button */}
            <button
              onClick={() => setShowHistory(true)}
              className="p-2 rounded-lg hover:bg-slate-700/50 text-slate-400 hover:text-white transition-colors mr-1"
              title="会话历史"
            >
              <History className="w-4 h-4" />
            </button>
            {/* New session button */}
            <button
              onClick={handleNewSession}
              className="p-2 rounded-lg hover:bg-slate-700/50 text-slate-400 hover:text-white transition-colors"
              title="新建会话"
            >
              <Plus className="w-4 h-4" />
            </button>
            {/* Mode toggle buttons */}
            <div className="flex items-center bg-slate-800/60 rounded-lg border border-slate-700/40 p-0.5 mr-2">
              <button
                onClick={() => { if (mode !== 'voice') handleBackToVoice(); }}
                className={`flex items-center gap-1 px-2.5 py-1 rounded-md text-xs transition-all ${
                  mode === 'voice'
                    ? 'bg-violet-500/20 text-violet-300 font-medium'
                    : 'text-slate-500 hover:text-slate-300'
                }`}
              >
                <Mic className="w-3 h-3" /> 语音
              </button>
              <button
                onClick={() => { if (mode !== 'chat') handleStartChat(); }}
                className={`flex items-center gap-1 px-2.5 py-1 rounded-md text-xs transition-all ${
                  mode === 'chat'
                    ? 'bg-violet-500/20 text-violet-300 font-medium'
                    : 'text-slate-500 hover:text-slate-300'
                }`}
              >
                <MessageSquare className="w-3 h-3" /> 文字
              </button>
              <button
                onClick={() => setMode('video')}
                className={`flex items-center gap-1 px-2.5 py-1 rounded-md text-xs transition-all ${
                  mode === 'video'
                    ? 'bg-violet-500/20 text-violet-300 font-medium'
                    : 'text-slate-500 hover:text-slate-300'
                }`}
              >
                <Film className="w-3 h-3" /> 视频
              </button>
            </div>
            {mode === 'chat' && (
              <button
                onClick={toggleTextEngine}
                className={`px-2 py-1 rounded-md text-[11px] font-medium transition-colors border ${
                  textEngine === 's2s'
                    ? 'bg-emerald-500/15 text-emerald-300 border-emerald-500/30'
                    : 'bg-slate-700/40 text-slate-300 border-slate-600/40'
                }`}
                title="切换文字对话引擎 (S2S 走 event 501, Coze 走 HTTP/SSE)"
              >
                {textEngine === 's2s' ? 'S2S' : 'Coze'}
              </button>
            )}
            {mode === 'voice' && (
              <button
                onClick={() => setShowSettings(!showSettings)}
                className="p-2 rounded-lg hover:bg-slate-700/50 text-slate-400 hover:text-white transition-colors"
                title="语音设置"
              >
                <Settings2 className="w-5 h-5" />
              </button>
            )}
          </div>
        </div>
      </header>

      <main className="max-w-5xl mx-auto px-4 py-6">
        {/* Settings Panel */}
        {showSettings && mode === 'voice' && (
          <SettingsPanel
            settings={settings}
            onChange={setSettings}
            voiceConfig={voiceConfig}
            onClose={() => setShowSettings(false)}
          />
        )}

        {mode === 'voice' ? (
          <>
            {/* Voice Panel */}
            <VoicePanel settings={settings} onVoiceEnd={handleVoiceEnd} chatHistory={chatMessages} sessionId={currentSessionId} onSessionCreated={handleSessionCreated} />

            {/* Architecture Info */}
            <div className="mt-6 p-4 rounded-xl bg-slate-800/40 border border-slate-700/40">
              <h3 className="text-xs font-semibold text-slate-400 uppercase tracking-wider mb-3">RTC 直路由语音架构</h3>
              <div className="grid grid-cols-1 md:grid-cols-3 gap-3 text-xs">
                <div className="p-3 rounded-lg bg-slate-700/30 border border-slate-600/30">
                  <div className="text-emerald-400 font-medium mb-1">上行链路</div>
                  <div className="text-slate-400">浏览器 RTC 麦克风 → 房间字幕/消息 → 后端前置路由</div>
                </div>
                <div className="p-3 rounded-lg bg-slate-700/30 border border-slate-600/30">
                  <div className="text-amber-400 font-medium mb-1">应答链路</div>
                  <div className="text-slate-400">知识库/工具结果 → ExternalTextToSpeech → 语音播报</div>
                </div>
                <div className="p-3 rounded-lg bg-slate-700/30 border border-slate-600/30">
                  <div className="text-violet-400 font-medium mb-1">当前目标</div>
                  <div className="text-slate-400">彻底绕开原生链纯 S2S 抢答，保证知识库结果能播报</div>
                </div>
              </div>
            </div>
          </>
        ) : mode === 'chat' ? (
          /* Chat Panel */
          handoff && (
            <ChatPanel
              key={`${handoff.sessionId}-${textEngine}`}
              sessionId={handoff.sessionId}
              voiceSubtitles={handoff.subtitles}
              settings={settings}
              onBack={handleBackToVoice}
              onMessagesChange={setChatMessages}
              useS2S={textEngine === 's2s'}
              playAudioReply={false}
            />
          )
        ) : (
          /* Video Panel */
          <VideoPanel />
        )}
      </main>

      {/* Session History Sidebar */}
      {showHistory && (
        <SessionHistoryPanel
          currentSessionId={currentSessionId}
          onSelectSession={handleSelectSession}
          onNewSession={handleNewSession}
          onClose={() => setShowHistory(false)}
        />
      )}
    </div>
  );
}