import React, { useRef, useCallback, useState, useEffect, useMemo } from "react";
import { ChevronsRight, ChevronDown, X } from 'lucide-react';
import { Switch } from 'antd';
import { MessageRenderer } from "./MessageRenderer";
import { InputBar } from "./InputBar";
import { useMessages } from "./useMessages";
import { DateDivider } from "./DateDivider";
import { LoadMoreButton } from "./LoadMoreButton";
import { ChatMessage } from "./types";
import { useDeviceType } from '@/hooks/useDeviceType';
import { useBrowserType } from '@/hooks/useBrowserType';

interface SmartChatBoxProps {
  isSmartChatBoxOpen: boolean;
  setIsSmartChatBoxOpen: (v: boolean) => void;
  projectId: string;
  userId: number;
  previewVideoUrl?: string | null;
  previewVideoId?: string | null;
  onClearPreview?: () => void;
  setIsFocusChatInput?: (v: boolean) => void;
  aiEditingResult?: any;
  /** 新消息回调：用于外层处理未展开时的气泡提示 */
  onNewMessage?: (snippet: string) => void;
}

interface MessageGroup {
  date: number;
  messages: ChatMessage[];
}

function BackToLatestButton({ onClick }: { onClick: () => void }) {
  return (
    <button
      onClick={onClick}
      className="fixed bottom-24 right-4 bg-blue-500 hover:bg-blue-400 text-white rounded-full p-2 shadow-lg"
      title="返回最新消息"
    >
      <ChevronDown size={20} />
    </button>
  );
}

export default function SmartChatBox({ 
  isSmartChatBoxOpen, 
  setIsSmartChatBoxOpen, 
  projectId, 
  userId,
  previewVideoUrl,
  previewVideoId,
  onClearPreview,
  setIsFocusChatInput,
  aiEditingResult,
  onNewMessage
}: SmartChatBoxProps) {
  // 消息列表引用
  const listRef = useRef<HTMLDivElement>(null);
  const [isAtBottom, setIsAtBottom] = useState(true);
  const { isMobile, isTablet, isDesktop } = useDeviceType();
  // 检查是否滚动到底部
  const checkIfAtBottom = useCallback(() => {
    if (listRef.current) {
      const { scrollHeight, scrollTop, clientHeight } = listRef.current;
      // 考虑一个小的误差范围（10px）
      const isBottom = scrollHeight - scrollTop - clientHeight <= 10;
      setIsAtBottom(isBottom);
    }
  }, []);

  // 处理滚动事件
  const handleScroll = useCallback(() => {
    checkIfAtBottom();
  }, [checkIfAtBottom]);

  useEffect(() => {
    console.log('previewVideoUrl', previewVideoUrl);
    console.log('previewVideoId', previewVideoId);
  }, [previewVideoUrl, previewVideoId]);

  // 监听滚动事件
  useEffect(() => {
    const listElement = listRef.current;
    if (listElement) {
      listElement.addEventListener('scroll', handleScroll);
      return () => {
        listElement.removeEventListener('scroll', handleScroll);
      };
    }
  }, [handleScroll]);

  // 处理消息更新时的滚动
  const handleMessagesUpdate = useCallback((shouldScroll: boolean) => {
    if (shouldScroll && listRef.current) {
      listRef.current.scrollTo({ top: listRef.current.scrollHeight, behavior: "smooth" });
    }
    // 更新底部状态
    checkIfAtBottom();
  }, [checkIfAtBottom]);

  // 使用消息管理 hook
  const [
    { messages, isLoading, error, hasMore, loadMoreMessages, backToLatest, isViewingHistory },
    { sendMessage },
    { enabled: systemPush, toggle: toggleSystemPush }
  ] = useMessages({ 
    config: { projectId, userId },
    onMessagesUpdate: handleMessagesUpdate
  });

  // 监听消息新增，向外层抛出前10个字符的文本片段
  const prevLenRef = useRef<number>(0);
  useEffect(() => {
    const len = messages.length;
    if (len > prevLenRef.current && len > 0) {
      const last = messages[len - 1];
      // 提取第一个文本块
      const textBlock = last.blocks.find(b => (b as any).type === 'text') as any;
      const text = textBlock?.text || '';
      if (text && onNewMessage) {
        const snippet = text.slice(0, 40);
        onNewMessage(snippet);
      }
    }
    prevLenRef.current = len;
  }, [messages, onNewMessage]);

  // 监听智能剪辑结果，自动发送消息到聊天框
//   useEffect(() => {
//     if (aiEditingResult && isSmartChatBoxOpen) {
//       const resultMessage = `🎉 AI智能剪辑完成！

// 📊 剪辑统计：
// • 视频时长：${aiEditingResult.duration || '未知'}秒
// • 剪辑片段：${aiEditingResult.clips || '未知'}个
// • 处理结果：${aiEditingResult.message || '剪辑成功'}

// 🎬 最终视频已生成，您可以在工作流中查看和下载。`;

//       // 自动发送系统消息
//       sendMessage([{
//         type: 'text',
//         content: resultMessage
//       }]);
//     }
//   }, [aiEditingResult, isSmartChatBoxOpen, sendMessage]);

  // 按日期分组消息
  const groupedMessages = React.useMemo(() => {
    const groups: MessageGroup[] = [];
    
    messages.forEach(message => {
      const messageDate = new Date(message.createdAt).setHours(0, 0, 0, 0);
      
      const existingGroup = groups.find(group => {
        const groupDate = new Date(group.date).setHours(0, 0, 0, 0);
        return groupDate === messageDate;
      });

      if (existingGroup) {
        existingGroup.messages.push(message);
      } else {
        groups.push({
          date: messageDate,
          messages: [message]
        });
      }
    });

    return groups.sort((a, b) => a.date - b.date);
  }, [messages]);

  const browserType = useBrowserType();
  /** 根据浏览器类型获取最大高度值 */
  const maxHeight = useMemo(() => {
      switch (browserType) {
          case 'Edge':
              return 'calc(100vh - 5.5rem)';
          case 'Chrome':
              return 'calc(100vh - 7rem)';
          default:
              return 'calc(100vh - 5.5rem)';
      }
  }, [browserType]);

  return (
    <div className={`${isMobile ? '' : 'h-full'} w-full text-gray-100 flex flex-col backdrop-blur-lg bg-black/30 border border-white/20 shadow-xl relative`} data-alt="smart-chat-box"
    style={{
      maxHeight: isMobile ? maxHeight : '',
    }}>
      {/* Header */}
      <div className={`px-4 py-3 border-b border-white/10 flex items-center justify-between ${isMobile ? 'sticky top-0 bg-[#141414] z-[1]' : ''}`} data-alt="chat-header">
        <div className="font-semibold flex items-center gap-2">
          <span>Chat</span>
          {/* System push toggle */}
          <Switch 
            checkedChildren="On"
            unCheckedChildren="Off"
            checked={systemPush}
            onChange={toggleSystemPush}
            className="ml-2"
          />
        </div>
        <div className="text-xs opacity-70">
          <X 
            className="w-6 h-6 cursor-pointer" 
            onClick={() => setIsSmartChatBoxOpen(false)} 
          />
        </div>
      </div>

      {/* Message list */}
      <div ref={listRef} className="flex-1 overflow-y-auto p-4" data-alt="message-list">
        {/* Load more button */}
        {hasMore && (
          <LoadMoreButton onClick={loadMoreMessages} loading={isLoading} />
        )}

        {/* Messages grouped by date */}
        <div className="space-y-3 pb-28">
          {groupedMessages.map((group) => (
            <React.Fragment key={group.date}>
              <DateDivider timestamp={group.date} />
              {group.messages.map((message) => (
                <MessageRenderer key={message.id} msg={message} sendMessage={sendMessage} />
              ))}
            </React.Fragment>
          ))}
        </div>
        
        {/* Loading indicator */}
        {isLoading && (
          <div className="flex justify-start space-x-1 p-2">
            <span className="w-2 h-2 bg-gray-400 rounded-full animate-bounce [animation-delay:-0.3s]"></span>
            <span className="w-2 h-2 bg-gray-400 rounded-full animate-bounce [animation-delay:-0.15s]"></span>
            <span className="w-2 h-2 bg-gray-400 rounded-full animate-bounce"></span>
          </div>
        )}

        {/* Back to latest button */}
        {isViewingHistory && !isAtBottom && (
          <BackToLatestButton onClick={backToLatest} />
        )}
      </div>

      {/* Input */}
      <InputBar 
        onSend={sendMessage} 
        setVideoPreview={(url, id) => {
          if (url === previewVideoUrl && id === previewVideoId) {
            onClearPreview?.();
          }
        }}
        initialVideoUrl={previewVideoUrl || undefined}
        initialVideoId={previewVideoId || undefined}
        setIsFocusChatInput={setIsFocusChatInput}
      />
    </div>
  );
}