"use client";

import { useChat } from "@ai-sdk/react";
import { DefaultChatTransport } from "ai";
import { useRouter, useSearchParams } from "next/navigation";
import { useCallback, useEffect, useMemo, useRef, useState } from "react";
import useSWR, { useSWRConfig } from "swr";
import { unstable_serialize } from "swr/infinite";
import { ChatHeader } from "@/components/chat-header";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog";
import { useArtifactSelector } from "@/hooks/use-artifact";
import { useAutoResume } from "@/hooks/use-auto-resume";
import { useChatVisibility } from "@/hooks/use-chat-visibility";
import { usePendingGeneration, type PendingGeneration } from "@/hooks/use-pending-generation";
import type { Vote } from "@/lib/db/schema";
import type { UserType } from "@/app/(auth)/auth";
import { ChatSDKError } from "@/lib/errors";
import type { Attachment, ChatMessage } from "@/lib/types";
import type { AppUsage } from "@/lib/usage";
import { fetcher, fetchWithErrorHandlers, generateUUID } from "@/lib/utils";
import { Artifact } from "@/components/artifact";
import { useDataStream } from "@/components/data-stream-provider";
import { Messages } from "@/components/messages";
import { MultimodalInput } from "@/components/multimodal-input";
import { getChatHistoryPaginationKey } from "@/components/sidebar-history";
import { toast } from "sonner";
import type { VisibilityType } from "@/components/visibility-selector";
import type { VideoGenerationParams } from "@/components/video-params-bar";
import type { ImageGenerationParams } from "@/components/image-params-bar";

type ImageGenerationPhase = "idle" | "queued" | "processing" | "finalizing" | "failed";

function normalizeImageParamsForProvider(
  params: ImageGenerationParams,
  providerType?: string
): ImageGenerationParams {
  const normalized = { ...params };
  const currentCount = normalized.imageCount || 1;

  if (providerType === "ruxa-image") {
    normalized.imageCount = 1;
    return normalized;
  }

  if (providerType === "alibaba-image") {
    normalized.imageCount = Math.min(Math.max(currentCount, 1), 6);
    return normalized;
  }

  if (providerType === "volcano-vision") {
    normalized.imageCount = Math.min(Math.max(currentCount, 1), 3);
    return normalized;
  }

  normalized.imageCount = Math.min(Math.max(currentCount, 1), 2);
  return normalized;
}

function sortMessagesByCreatedAt(messages: ChatMessage[]): ChatMessage[] {
  return [...messages].sort((a, b) => {
    const timeA = (a as any).createdAt ? new Date((a as any).createdAt).getTime() : 0;
    const timeB = (b as any).createdAt ? new Date((b as any).createdAt).getTime() : 0;
    return timeA - timeB;
  });
}

function hasImageMarkdown(parts?: Array<any>) {
  if (!parts || parts.length === 0) return false;
  return parts.some(
    (part) =>
      part?.type === "text" &&
      typeof part.text === "string" &&
      (part.text.includes("![thumb|") ||
        part.text.includes("![thumb|||") ||
        part.text.includes("![Generated Image"))
  );
}

export function Chat({
  id,
  initialMessages,
  initialChatModel,
  initialVisibilityType,
  isReadonly,
  autoResume,
  initialLastContext,
  userType,
}: {
  id: string;
  initialMessages: ChatMessage[];
  initialChatModel: string;
  initialVisibilityType: VisibilityType;
  isReadonly: boolean;
  autoResume: boolean;
  initialLastContext?: AppUsage;
  userType?: UserType;
}) {
  const router = useRouter();

  const { visibilityType } = useChatVisibility({
    chatId: id,
    initialVisibilityType,
  });

  // 🆕 持久化生成任务状态（解决用户离开再返回时加载状态丢失）
  const { pendingGeneration, startGeneration, completeGeneration } = usePendingGeneration(id);
  
  // 🆕 标记是否已经尝试刷新过（避免无限刷新）
  const hasTriedRefreshRef = useRef(false);
  
  
  // 🆕 跟踪是否正在生成图片（用于占位图显示）
  const [isGeneratingImageFlag, setIsGeneratingImageFlag] = useState(false);
  const [imageGenerationPhase, setImageGenerationPhase] = useState<ImageGenerationPhase>("idle");
  const [imageGenerationStartedAt, setImageGenerationStartedAt] = useState<number | null>(null);
  const imageGenerationPhaseRef = useRef<ImageGenerationPhase>("idle");
  const imagePlaceholderTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
  
  // 🆕 存储通过 data-appendMessage 添加的消息，避免与 useChat 内部状态冲突
  const [appendedMessages, setAppendedMessages] = useState<ChatMessage[]>([]);
  
  // 🆕 当检测到恢复的 pendingGeneration 时，刷新页面获取最新消息
  useEffect(() => {
    if (pendingGeneration && !hasTriedRefreshRef.current) {
      // 检查最后一条消息是否已经是 AI 回复
      const lastMessage = initialMessages.length > 0 ? initialMessages[initialMessages.length - 1] : null;
      
      if (lastMessage?.role === "assistant") {
        // 最后一条已经是 AI 回复，说明生成已完成，清除 pending 状态
        console.log("[Chat] 🎉 检测到生成已完成（最后消息是 AI 回复），清除 pending 状态");
        completeGeneration();
      } else if (lastMessage?.role === "user") {
        // 最后一条是用户消息，可能还在生成中，或者已经完成但页面数据过期
        // 标记已尝试刷新，然后刷新页面获取最新数据
        hasTriedRefreshRef.current = true;
        console.log("[Chat] 🔄 检测到恢复的 pending 状态，刷新页面获取最新消息...");
        
        // 延迟一小段时间再刷新，避免立即刷新
        setTimeout(() => {
          router.refresh();
        }, 500);
      }
    }
  }, [pendingGeneration, initialMessages, completeGeneration, router]);

  const updateImageGenerationPhase = useCallback((nextPhase: ImageGenerationPhase) => {
    imageGenerationPhaseRef.current = nextPhase;
    setImageGenerationPhase(nextPhase);

    if (nextPhase === "idle" || nextPhase === "failed") {
      setIsGeneratingImageFlag(false);
      setImageGenerationStartedAt(null);
      return;
    }

    setIsGeneratingImageFlag(true);
    setImageGenerationStartedAt((previous) => previous ?? Date.now());
  }, []);

  // 清理占位图定时器
  useEffect(() => {
    return () => {
      if (imagePlaceholderTimerRef.current) {
        clearTimeout(imagePlaceholderTimerRef.current);
        imagePlaceholderTimerRef.current = null;
      }
    };
  }, []);

  const { mutate } = useSWRConfig();

  // Handle browser back/forward navigation
  useEffect(() => {
    const handlePopState = () => {
      // When user navigates back/forward, refresh to sync with URL
      router.refresh();
    };

    window.addEventListener("popstate", handlePopState);
    return () => window.removeEventListener("popstate", handlePopState);
  }, [router]);
  const { setDataStream } = useDataStream();

  const [input, setInput] = useState<string>("");
  const [usage, setUsage] = useState<AppUsage | undefined>(initialLastContext);
  const [showCreditCardAlert, setShowCreditCardAlert] = useState(false);
  const [currentModelId, setCurrentModelId] = useState(initialChatModel);
  // 图片处理状态，防止重复点击
  const [isProcessingEnhance, setIsProcessingEnhance] = useState(false);
  const [isProcessingRmbg, setIsProcessingRmbg] = useState(false);
  const [isProcessingExtend, setIsProcessingExtend] = useState(false);
  const [isProcessingAngleEdit, setIsProcessingAngleEdit] = useState(false);
  const [isProcessingWatermarkRemove, setIsProcessingWatermarkRemove] = useState(false);
  const currentModelIdRef = useRef(currentModelId);
  
  // 🆕 视频参数状态
  const [videoParams, setVideoParams] = useState<VideoGenerationParams | null>(null);
  
  // 🆕 图片参数状态（默认值：auto比例，2K分辨率）
  const [imageParams, setImageParams] = useState<ImageGenerationParams>({
    aspectRatio: "auto",
    imageSize: "2K"
  });

  // 🆕 从 localStorage 读取保存的图片参数
  useEffect(() => {
    try {
      const saved = localStorage.getItem("gemini-image-params");
      if (saved) {
        const parsed = JSON.parse(saved);
        // 确保所有字段都有值，避免传递 undefined
        setImageParams({
          aspectRatio: "auto",
          imageSize: "2K",
          imageCount: 1,
          ...parsed,
        });
      }
    } catch (e) {
      console.error("Failed to load image params:", e);
    }
  }, []);

  // 🆕 保存图片参数到 localStorage
  const handleImageParamsChange = (params: ImageGenerationParams) => {
    const normalized = normalizeImageParamsForProvider(params, currentModel?.providerType);
    setImageParams(normalized);
    try {
      localStorage.setItem("gemini-image-params", JSON.stringify(normalized));
    } catch (e) {
      console.error("Failed to save image params:", e);
    }
    console.log("[Chat] Image params updated:", normalized);
  };

  // 🆕 获取模型列表以检查是否是视频模型/图片模型
  const { data: modelsData } = useSWR<{
    models: Array<{
      id: string;
      modelId: string;
      displayName: string;
      providerType: string;
      supportsVision?: boolean;
      supportsImageGen?: boolean;
    }>;
  }>("/api/models", fetcher);

  const currentModel = modelsData?.models?.find(m => m.id === currentModelId);
  const isVideoModel = currentModel?.providerType === "volcano-video";
  const isImageModel = currentModel?.supportsImageGen === true;
  
  // 🔍 调试日志
  console.log('[Chat] Render - currentModelId:', currentModelId);
  console.log('[Chat] Render - modelsData loaded:', !!modelsData);
  console.log('[Chat] Render - currentModel:', currentModel?.displayName, {
    id: currentModel?.id,
    supportsImageGen: currentModel?.supportsImageGen,
    providerType: currentModel?.providerType,
    isImageModel,
    imageParams
  });
  
  // 使用 ref 保存视频/图片相关状态，以便在 prepareSendMessagesRequest 中访问最新值
  const isVideoModelRef = useRef(isVideoModel);
  const videoParamsRef = useRef(videoParams);
  const isImageModelRef = useRef(isImageModel);
  const imageParamsRef = useRef(imageParams);
  
  useEffect(() => {
    isVideoModelRef.current = isVideoModel;
    videoParamsRef.current = videoParams;
    isImageModelRef.current = isImageModel;
    imageParamsRef.current = imageParams;
    console.log("[Chat] Refs updated - imageParams:", imageParams);
  }, [isVideoModel, videoParams, isImageModel, imageParams]);
  
  // 调试日志
  console.log("[Chat Debug] currentModelId:", currentModelId);
  console.log("[Chat Debug] currentModel:", currentModel);
  console.log("[Chat Debug] isVideoModel:", isVideoModel);

  // 🆕 当切换到视频模型时，自动初始化 videoParams
  useEffect(() => {
    if (isVideoModel && !videoParams) {
      const defaultParams: VideoGenerationParams = {
        mode: "text-to-video",
        resolution: "720p",
        ratio: "16:9",
        duration: 5,
        watermark: false,
        cameraFixed: false,
        cameraMove: "none",
        fps: 24,
      };
      setVideoParams(defaultParams);
      console.log("[Chat] 视频模型已选择，初始化默认参数:", defaultParams);
    } else if (!isVideoModel && videoParams) {
      // 切换到非视频模型时清空 videoParams
      setVideoParams(null);
      console.log("[Chat] 已切换到非视频模型，清空视频参数");
    }
  }, [isVideoModel, videoParams]);

  // 🆕 当切换到图片模型时，强制更新 imageParams（确保组件重新渲染）
  useEffect(() => {
    if (isImageModel) {
      setImageParams((prev) => {
        const next = normalizeImageParamsForProvider(prev, currentModel?.providerType);
        if (JSON.stringify(prev) === JSON.stringify(next)) return prev;
        try {
          localStorage.setItem("gemini-image-params", JSON.stringify(next));
        } catch {}
        return next;
      });
      console.log("[Chat] 图片模型已激活，参数已按当前模型规范化");
    }
  }, [isImageModel, currentModel?.providerType]);

  useEffect(() => {
    currentModelIdRef.current = currentModelId;
    // 调试：在控制台显示当前模型切换
    console.log(`[Chat] Model changed to: ${currentModelId}`);
  }, [currentModelId]);

  const {
    messages,
    setMessages,
    sendMessage,
    status,
    stop,
    regenerate,
    resumeStream,
  } = useChat<ChatMessage>({
    id,
    messages: initialMessages,
    experimental_throttle: 100,
    generateId: generateUUID,
    transport: new DefaultChatTransport({
      api: "/api/chat",
      fetch: fetchWithErrorHandlers,
      prepareSendMessagesRequest(request) {
        console.log("[Chat] Preparing request, videoParams:", videoParamsRef.current);
        console.log("[Chat] Preparing request, imageParams:", imageParamsRef.current);
        console.log("[Chat] Is video model:", isVideoModelRef.current);
        console.log("[Chat] Is image model:", isImageModelRef.current);
        return {
          body: {
            id: request.id,
            message: request.messages.at(-1),
            selectedChatModel: currentModelIdRef.current,
            selectedVisibilityType: visibilityType,
            videoParams: videoParamsRef.current || undefined, // 🆕 传递视频参数（使用ref获取最新值）
            imageParams: imageParamsRef.current || undefined, // 🆕 传递图片参数（使用ref获取最新值）
            ...request.body,
          },
        };
      },
    }),
    onData: (dataPart: any) => {
      setDataStream((ds) => (ds ? [...ds, dataPart] : []));
      if (dataPart.type === "data-usage") {
        setUsage(dataPart.data);
      }
      
      // 🆕 处理后端返回的自定义消息（用于图片/视频生成的非流式响应）
      if (dataPart.type === "data-appendMessage") {
        try {
          const messageData = typeof dataPart.data === 'string' 
            ? JSON.parse(dataPart.data) 
            : dataPart.data;
            
          console.log("[Chat] Received appendMessage:", messageData);
          
          const hasImageGenStartMarker = messageData.parts?.some(
            (part: any) => part.type === "text" && part.text?.includes("<!-- IMAGE_GENERATION_START -->")
          );
          const hasImageGenEndMarker = messageData.parts?.some(
            (part: any) => part.type === "text" && part.text?.includes("<!-- IMAGE_GENERATION_END -->")
          );
          const hasLegacyGeneratingMarker = messageData.parts?.some(
            (part: any) => part.type === "text" && part.text?.includes("<!-- GENERATING_IMAGE -->")
          );
          const isMarkerOnlyMessage = messageData.parts?.every((part: any) => {
            if (part.type !== "text" || !part.text) return false;
            const cleanedText = part.text
              .replace(/\n*<!-- IMAGE_GENERATION_START -->\n*/g, "")
              .replace(/\n*<!-- IMAGE_GENERATION_END -->\n*/g, "")
              .replace(/\n*<!-- GENERATING_IMAGE -->\n*/g, "")
              .trim();
            return cleanedText.length === 0;
          });

          if (hasImageGenEndMarker && isMarkerOnlyMessage) {
            console.log("[Chat] 🖼️ Image generation entered finalizing stage");
            if (imagePlaceholderTimerRef.current) {
              clearTimeout(imagePlaceholderTimerRef.current);
              imagePlaceholderTimerRef.current = null;
            }
            updateImageGenerationPhase("finalizing");
            return; // 不渲染标记消息
          }

          if (hasImageGenStartMarker && isMarkerOnlyMessage) {
            console.log("[Chat] 🖼️ Image generation started, show placeholder");
            if (imagePlaceholderTimerRef.current) {
              clearTimeout(imagePlaceholderTimerRef.current);
              imagePlaceholderTimerRef.current = null;
            }
            updateImageGenerationPhase("processing");
            return; // 不渲染标记消息
          }

          if (hasLegacyGeneratingMarker) {
            console.log("[Chat] 🖼️ Detected legacy marker, will show placeholder after delay");
            const hasDisplayText = messageData.parts?.some((part: any) => {
              if (part.type !== "text" || !part.text) return false;
              const cleanedText = part.text.replace(/\n*<!-- GENERATING_IMAGE -->\n*/g, "").trim();
              return cleanedText.length > 0;
            });
            if (!hasDisplayText) {
              console.log("[Chat] ⚠️ Marker message has no display text, skip image placeholder timer");
              return;
            }
            if (imagePlaceholderTimerRef.current) {
              clearTimeout(imagePlaceholderTimerRef.current);
              imagePlaceholderTimerRef.current = null;
            }
            imagePlaceholderTimerRef.current = setTimeout(() => {
              console.log("[Chat] 🖼️ Now showing placeholder after 3s delay");
              updateImageGenerationPhase("processing");
              imagePlaceholderTimerRef.current = null;
            }, 3000);
          }
          
          // 🆕 检测是否包含图片（生成完成）
          const messageText = messageData.parts?.[0]?.text || "";
          console.log("[Chat] 📝 Message text preview:", messageText.substring(0, 100));
          
          const hasImage = hasImageMarkdown(messageData.parts);
          console.log("[Chat] 🔍 hasImage check:", hasImage);
          
          if (hasImage) {
            console.log("[Chat] 🎉 Image generated, hiding placeholder");
            if (imagePlaceholderTimerRef.current) {
              clearTimeout(imagePlaceholderTimerRef.current);
              imagePlaceholderTimerRef.current = null;
            }
            updateImageGenerationPhase("idle");
          }
          
          // 🆕 将消息添加到 appendedMessages 状态，而不是直接修改 useChat 的 messages
          // 这样可以避免与 useChat 内部状态冲突导致消息丢失
          const newMessage: ChatMessage = {
            id: messageData.id,
            role: messageData.role,
            content: messageData.parts?.[0]?.text || "",
            createdAt: new Date(),
            parts: messageData.parts || [],
            attachments: [],
          } as ChatMessage;
          
          setAppendedMessages((prev) => {
            // 检查消息是否已存在
            if (prev.some(m => m.id === messageData.id)) {
              console.log("[Chat] Appended message already exists, skipping:", messageData.id);
              return prev;
            }
            console.log("[Chat] Adding to appendedMessages:", messageData.id);
            return [...prev, newMessage];
          });

          const messageTextForErrorCheck = messageData.parts
            ?.filter((part: any) => part.type === "text" && typeof part.text === "string")
            .map((part: any) => part.text)
            .join("\n")
            .trim();
          const isLikelyGenerationError =
            !hasImage &&
            !!messageTextForErrorCheck &&
            /失败|超时|重试|error|failed/i.test(messageTextForErrorCheck) &&
            imageGenerationPhaseRef.current !== "idle";
          if (isLikelyGenerationError) {
            console.log("[Chat] ❌ Generation error detected, reset loading state");
            updateImageGenerationPhase("failed");
          }
          
          // 🆕 收到消息，清除持久化状态
          completeGeneration();
        } catch (e) {
          console.error("[Chat] Failed to parse data-appendMessage:", e);
        }
      }
    },
    onFinish: async () => {
      mutate(unstable_serialize(getChatHistoryPaginationKey));
      // 🆕 生成完成，清除持久化状态
      completeGeneration();
      console.log("[Chat] onFinish called");
      
      // 🆕 从数据库重新加载消息，确保 data-appendMessage 的消息正确显示
      // 这是根治方案 B：后端已保存消息到数据库，前端从数据库重新加载
      try {
        const mergeMessagesFromDatabase = (dbMessages: ChatMessage[]) => {
          setMessages((prev) => {
            const mergedMap = new Map<string, ChatMessage>();
            prev.forEach((message) => mergedMap.set(message.id, message));
            dbMessages.forEach((message) => mergedMap.set(message.id, message));
            return sortMessagesByCreatedAt(Array.from(mergedMap.values()));
          });

          const persistedIds = new Set<string>(dbMessages.map((message) => message.id));
          setAppendedMessages((prev) => prev.filter((message) => !persistedIds.has(message.id)));
        };

        const reloadMessagesOnce = async () => {
          const response = await fetch(`/api/messages?chatId=${id}&_t=${Date.now()}`, {
            cache: "no-store",
          });
          if (!response.ok) return { hasImage: false };

          const data = await response.json();
          if (!data.messages || !Array.isArray(data.messages)) {
            return { hasImage: false };
          }

          const dbMessages = data.messages as ChatMessage[];
          console.log("[Chat] Reloading messages from database:", dbMessages.length);
          mergeMessagesFromDatabase(dbMessages);

          const hasPersistedImage = dbMessages.some((message) => hasImageMarkdown((message as any).parts));
          return { hasImage: hasPersistedImage };
        };

        // 延迟一小段时间确保数据库写入完成
        await new Promise((resolve) => setTimeout(resolve, 500));

        let { hasImage } = await reloadMessagesOnce();
        if (!hasImage && imageGenerationPhaseRef.current === "finalizing") {
          for (let attempt = 1; attempt <= 6; attempt++) {
            await new Promise((resolve) => setTimeout(resolve, 600));
            const result = await reloadMessagesOnce();
            hasImage = result.hasImage;
            if (hasImage) break;
          }
        }

        if (
          hasImage ||
          (imageGenerationPhaseRef.current !== "idle" &&
            imageGenerationPhaseRef.current !== "failed")
        ) {
          updateImageGenerationPhase("idle");
        }
      } catch (error) {
        console.error("[Chat] Failed to reload messages:", error);
      }
    },
    onError: (error) => {
      if (imagePlaceholderTimerRef.current) {
        clearTimeout(imagePlaceholderTimerRef.current);
        imagePlaceholderTimerRef.current = null;
      }
      updateImageGenerationPhase("failed");

      if (error instanceof ChatSDKError) {
        // Check if it's a credit card error
        if (
          error.message?.includes("AI Gateway requires a valid credit card")
        ) {
          setShowCreditCardAlert(true);
        } else {
          toast.error(error.message);
        }
      }
    },
  });

  // 🆕 保存 initialMessages 的引用，防止历史消息丢失
  // 当 useChat 内部状态重置时，我们仍然有初始消息
  const initialMessagesRef = useRef<ChatMessage[]>(initialMessages);
  useEffect(() => {
    // 只在初始化时设置，不在后续更新
    if (initialMessagesRef.current.length === 0 && initialMessages.length > 0) {
      initialMessagesRef.current = initialMessages;
    }
  }, [initialMessages]);

  // 调试：监控聊天状态变化 & 持久化生成状态
  // 使用 ref 来访问最新的 modelsData，避免依赖数组问题
  const modelsDataRef = useRef(modelsData);
  useEffect(() => {
    modelsDataRef.current = modelsData;
  }, [modelsData]);
  
  useEffect(() => {
    console.log(`[Chat] Status changed: ${status}`);
    
    // 🆕 当状态变为 submitted 时，记录生成任务
    if (status === "submitted") {
      // 判断模型类型 - 使用 ref 获取最新的 modelsData
      const models = modelsDataRef.current?.models;
      const model = models?.find((m: any) => m.id === currentModelId);
      
      let modelType: PendingGeneration["modelType"] = "other";
      // 🆕 gemini-image 和 huanke-gemini 都视为 gemini 类型
      if (model?.providerType === "gemini" || model?.providerType === "gemini-image" || model?.providerType === "huanke-gemini") modelType = "gemini";
      else if (model?.providerType === "volcano-vision") modelType = "volcano-vision";
      else if (model?.providerType === "volcano-video") modelType = "volcano-video";
      else if (model?.providerType === "qianwen-video") modelType = "qianwen-video";
      else if (model?.providerType === "alibaba-image" || model?.providerType === "ruxa-image") modelType = "alibaba-image";
      
      console.log(`[Chat] 🚀 记录生成任务: modelType=${modelType}, modelId=${currentModelId}`);
      startGeneration(currentModelId, modelType);

      if (modelType === "gemini" || modelType === "volcano-vision" || modelType === "alibaba-image") {
        updateImageGenerationPhase("queued");
      }
    }
  }, [status, currentModelId, startGeneration, updateImageGenerationPhase]);

  const searchParams = useSearchParams();
  const query = searchParams.get("query");
  const editImageUrl = searchParams.get("editImage");

  const [hasAppendedQuery, setHasAppendedQuery] = useState(false);
  const [hasLoadedEditImage, setHasLoadedEditImage] = useState(false);

  useEffect(() => {
    if (query && !hasAppendedQuery) {
      sendMessage({
        role: "user" as const,
        parts: [{ type: "text", text: query }],
      });

      setHasAppendedQuery(true);
      window.history.replaceState({}, "", `/chat/${id}`);
    }
  }, [query, sendMessage, hasAppendedQuery, id]);

  // 🆕 处理从Gallery跳转过来的图片编辑请求
  useEffect(() => {
    if (editImageUrl && !hasLoadedEditImage) {
      const fileName = editImageUrl.split('/').pop()?.split('?')[0] || `image-${Date.now()}.jpg`;
      
      // 推断图片类型
      let contentType = "image/jpeg";
      if (fileName.toLowerCase().endsWith(".png")) contentType = "image/png";
      if (fileName.toLowerCase().endsWith(".webp")) contentType = "image/webp";
      if (fileName.toLowerCase().endsWith(".gif")) contentType = "image/gif";

      setAttachments([{
        url: decodeURIComponent(editImageUrl),
        name: fileName,
        contentType: contentType,
      }]);

      // 自动填充提示词
      setInput("请帮我编辑这张图片：");

      setHasLoadedEditImage(true);
      window.history.replaceState({}, "", `/chat/${id}`);
    }
  }, [editImageUrl, hasLoadedEditImage, id, setInput]);

  // 🆕 处理从导航栏图片编辑器跳转过来的图片编辑请求
  const [hasLoadedPendingImage, setHasLoadedPendingImage] = useState(false);
  useEffect(() => {
    if (!hasLoadedPendingImage) {
      try {
        // 安全地访问sessionStorage（某些浏览器设置可能禁止访问）
        let pendingImage: string | null = null;
        try {
          pendingImage = sessionStorage.getItem("pending-edited-image");
        } catch (storageError) {
          // sessionStorage不可用（如隐私模式），忽略错误继续执行
          console.warn("sessionStorage不可用，跳过待处理图片加载:", storageError);
        }
        
        if (pendingImage) {
          // 清除 sessionStorage 中的数据，避免重复添加
          try {
            sessionStorage.removeItem("pending-edited-image");
          } catch (removeError) {
            // 忽略清除错误
          }
          
          // 判断是 base64 data URL 还是普通 URL
          const fileName = pendingImage.startsWith("data:image/")
            ? `edited-image-${Date.now()}.png`
            : pendingImage.split('/').pop()?.split('?')[0] || `image-${Date.now()}.jpg`;
          
          // 推断图片类型
          let contentType = "image/png";
          if (pendingImage.startsWith("data:image/jpeg") || pendingImage.startsWith("data:image/jpg")) {
            contentType = "image/jpeg";
          } else if (pendingImage.startsWith("data:image/webp")) {
            contentType = "image/webp";
          } else if (pendingImage.startsWith("data:image/gif")) {
            contentType = "image/gif";
          } else if (!pendingImage.startsWith("data:")) {
            // 普通 URL，根据文件名推断
            if (fileName.toLowerCase().endsWith(".jpg") || fileName.toLowerCase().endsWith(".jpeg")) {
              contentType = "image/jpeg";
            } else if (fileName.toLowerCase().endsWith(".webp")) {
              contentType = "image/webp";
            } else if (fileName.toLowerCase().endsWith(".gif")) {
              contentType = "image/gif";
            }
          }

          setAttachments((prev) => [
            ...prev,
            {
              url: pendingImage,
              name: fileName,
              contentType: contentType,
            },
          ]);

          // 自动填充提示词（如果输入框为空）
          setInput((prev) => prev || "请帮我处理这张图片：");

          setHasLoadedPendingImage(true);
        }
      } catch (error) {
        console.error("读取待处理图片失败:", error);
        setHasLoadedPendingImage(true);
      }
    }
  }, [hasLoadedPendingImage, setInput]);

  const { data: votes } = useSWR<Vote[]>(
    messages.length >= 2 ? `/api/vote?chatId=${id}` : null,
    fetcher
  );

  const [attachments, setAttachments] = useState<Attachment[]>([]);
  const isArtifactVisible = useArtifactSelector((state) => state.isVisible);

  // 处理图片编辑请求
  const handleImageEdit = (imageUrl: string) => {
    // 优化：直接使用 URL 构造附件对象，无需重新下载上传
    // 后端 API 会在发送时处理 URL（如果需要 Base64 转换）
    const fileName = imageUrl.split('/').pop()?.split('?')[0] || `image-${Date.now()}.jpg`;
    
    // 简单的类型推断
    let contentType = "image/jpeg";
    if (fileName.toLowerCase().endsWith(".png")) contentType = "image/png";
    if (fileName.toLowerCase().endsWith(".webp")) contentType = "image/webp";
    if (fileName.toLowerCase().endsWith(".gif")) contentType = "image/gif";

    setAttachments((prev) => [
      ...prev,
      {
        url: imageUrl,
        name: fileName,
        contentType: contentType,
      },
    ]);

    // 如果输入框为空，自动填入提示词
    setInput((prev) => prev ? prev : "请帮我编辑这张图片：");
  };

  // 处理画图标注完成
  const handleDrawingComplete = async (annotatedImageUrl: string) => {
    // annotatedImageUrl 是 base64 data URL 格式，需要先上传到服务器获取 URL
    const fileName = `annotated-${Date.now()}.png`;
    
    try {
      // 如果是 base64 格式，先上传到服务器
      if (annotatedImageUrl.startsWith("data:")) {
        toast.info("正在上传标注图片...");
        
        // 将 base64 转换为 Blob
        const response = await fetch(annotatedImageUrl);
        const blob = await response.blob();
        
        // 创建 FormData 上传
        const formData = new FormData();
        formData.append("file", blob, fileName);
        
        const uploadResponse = await fetch("/api/files/upload", {
          method: "POST",
          body: formData,
        });
        
        if (!uploadResponse.ok) {
          throw new Error("上传失败");
        }
        
        const uploadResult = await uploadResponse.json();
        
        setAttachments((prev) => [
          ...prev,
          {
            url: uploadResult.url,
            name: fileName,
            contentType: "image/png",
          },
        ]);
        
        toast.success("标注图片已添加");
      } else {
        // 如果已经是 URL，直接使用
        setAttachments((prev) => [
          ...prev,
          {
            url: annotatedImageUrl,
            name: fileName,
            contentType: "image/png",
          },
        ]);
      }

      // 如果输入框为空，自动填入提示词
      setInput((prev) => prev ? prev : "请根据我的标注修改这张图片：");
    } catch (error) {
      console.error("上传标注图片失败:", error);
      toast.error("上传标注图片失败，请重试");
    }
  };

  // 处理图片变清晰
  const handleImageEnhance = async (imageUrl: string) => {
    // 防止重复点击
    if (isProcessingEnhance || isProcessingRmbg || isProcessingExtend) {
      toast.info("正在处理中，请稍候...");
      return;
    }
    
    setIsProcessingEnhance(true);
    const messageId = generateUUID();
    
    // 创建临时加载消息
    const loadingMessage: ChatMessage = {
      id: messageId,
      role: "assistant",
      parts: [{ type: "text", text: "正在变清晰..." }],
      createdAt: new Date().toISOString(),
    } as ChatMessage;
    
    setMessages((prev) => [...prev, loadingMessage]);
    
    // 延迟滚动到底部，确保DOM已更新
    setTimeout(() => {
      const messagesContainer = document.querySelector('[role="log"]');
      if (messagesContainer) {
        messagesContainer.scrollTo({
          top: messagesContainer.scrollHeight,
          behavior: "smooth",
        });
      }
    }, 100);
    
    try {
      // 获取图片并转换为Base64
      const response = await fetch(imageUrl);
      const blob = await response.blob();
      const reader = new FileReader();
      
      reader.onloadend = async () => {
        try {
          const base64Data = (reader.result as string).split(",")[1];
          
          // 调用变清晰API
          const enhanceResponse = await fetch("/api/enhance", {
            method: "POST",
            headers: {
              "Content-Type": "application/json",
            },
            body: JSON.stringify({
              image_base64: base64Data,
              prompt: "图片变清晰处理",
            }),
          });

          if (!enhanceResponse.ok) {
            const error = await enhanceResponse.json();
            throw new Error(error.error || "变清晰处理失败");
          }

          const result = await enhanceResponse.json();

          if (result.success && result.original_url) {
            // 构造图片Markdown（使用与Gemini生成相同的格式）
            const imageMarkdown = `![thumb|||${result.original_url}|||2K](${result.thumbnail_url || result.original_url})`;
            
            // 创建最终消息（前端显示用）
            const finalMessage: ChatMessage = {
              id: messageId,
              role: "assistant",
              parts: [{ type: "text", text: imageMarkdown }],
              metadata: {
                createdAt: new Date().toISOString(),
              },
            } as ChatMessage;
            
            // 更新消息
            setMessages((prev) => 
              prev.map((msg) => (msg.id === messageId ? finalMessage : msg))
            );
            
            // 滚动到底部，显示处理结果
            setTimeout(() => {
              const messagesContainer = document.querySelector('[role="log"]');
              if (messagesContainer) {
                messagesContainer.scrollTo({
                  top: messagesContainer.scrollHeight,
                  behavior: "smooth",
                });
              }
            }, 100);
            
            // 保存消息到数据库
            try {
              await fetch("/api/messages", {
                method: "POST",
                headers: {
                  "Content-Type": "application/json",
                },
                body: JSON.stringify({
                  chatId: id,
                  message: {
                    id: messageId,
                    role: "assistant",
                    parts: [{ type: "text", text: imageMarkdown }],
                    attachments: [],
                    createdAt: new Date().toISOString(),
                  },
                }),
              });
            } catch (saveError) {
              console.error("[Chat] Failed to save message:", saveError);
            }
            
            toast.success(`变清晰完成！处理时间: ${result.processing_time?.toFixed(2) || "未知"}秒`);
          } else {
            throw new Error(result.error || "变清晰处理失败");
          }
        } catch (error) {
          console.error("[变清晰] 错误:", error);
          toast.error(error instanceof Error ? error.message : "变清晰失败，请稍后重试");
          // 移除加载消息
          setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        } finally {
          console.log("[变清晰] finally 块执行，重置 isProcessingEnhance");
          setIsProcessingEnhance(false);
        }
      };
      
      reader.onerror = () => {
        console.log("[变清晰] reader.onerror 执行，重置 isProcessingEnhance");
        toast.error("图片读取失败");
        setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        setIsProcessingEnhance(false);
      };
      
      reader.readAsDataURL(blob);
    } catch (error) {
      console.error("[变清晰] 错误:", error);
      console.log("[变清晰] 外层 catch 执行，重置 isProcessingEnhance");
      toast.error(error instanceof Error ? error.message : "变清晰失败，请稍后重试");
      setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
      setIsProcessingEnhance(false);
    }
  };

  // 处理图片抠图
  const handleImageRmbg = async (imageUrl: string) => {
    // 防止重复点击
    if (isProcessingEnhance || isProcessingRmbg || isProcessingExtend) {
      toast.info("正在处理中，请稍候...");
      return;
    }
    
    setIsProcessingRmbg(true);
    const messageId = generateUUID();
    
    // 创建临时加载消息
    const loadingMessage: ChatMessage = {
      id: messageId,
      role: "assistant",
      parts: [{ type: "text", text: "正在抠图..." }],
      createdAt: new Date().toISOString(),
    } as ChatMessage;
    
    setMessages((prev) => [...prev, loadingMessage]);
    
    // 延迟滚动到底部，确保DOM已更新
    setTimeout(() => {
      const messagesContainer = document.querySelector('[role="log"]');
      if (messagesContainer) {
        messagesContainer.scrollTo({
          top: messagesContainer.scrollHeight,
          behavior: "smooth",
        });
      }
    }, 100);
    
    try {
      // 获取图片并转换为Base64
      const response = await fetch(imageUrl);
      const blob = await response.blob();
      const reader = new FileReader();
      
      reader.onloadend = async () => {
        try {
          const base64Data = (reader.result as string).split(",")[1];
          
          // 调用抠图API
          const rmbgResponse = await fetch("/api/rmbg", {
            method: "POST",
            headers: {
              "Content-Type": "application/json",
            },
            body: JSON.stringify({
              image_base64: base64Data,
              prompt: "抠图处理",
            }),
          });

          if (!rmbgResponse.ok) {
            const error = await rmbgResponse.json();
            throw new Error(error.error || "抠图处理失败");
          }

          const result = await rmbgResponse.json();

          if (result.success && result.original_url) {
            // 构造图片Markdown（使用与Gemini生成相同的格式）
            const imageMarkdown = `![thumb|||${result.original_url}|||2K](${result.thumbnail_url || result.original_url})`;
            
            // 创建最终消息（前端显示用）
            const finalMessage: ChatMessage = {
              id: messageId,
              role: "assistant",
              parts: [{ type: "text", text: imageMarkdown }],
              metadata: {
                createdAt: new Date().toISOString(),
              },
            } as ChatMessage;
            
            // 更新消息
            setMessages((prev) => 
              prev.map((msg) => (msg.id === messageId ? finalMessage : msg))
            );
            
            // 滚动到底部，显示处理结果
            setTimeout(() => {
              const messagesContainer = document.querySelector('[role="log"]');
              if (messagesContainer) {
                messagesContainer.scrollTo({
                  top: messagesContainer.scrollHeight,
                  behavior: "smooth",
                });
              }
            }, 100);
            
            // 保存消息到数据库
            try {
              await fetch("/api/messages", {
                method: "POST",
                headers: {
                  "Content-Type": "application/json",
                },
                body: JSON.stringify({
                  chatId: id,
                  message: {
                    id: messageId,
                    role: "assistant",
                    parts: [{ type: "text", text: imageMarkdown }],
                    attachments: [],
                    createdAt: new Date().toISOString(),
                  },
                }),
              });
            } catch (saveError) {
              console.error("[Chat] Failed to save message:", saveError);
            }
            
            toast.success(`抠图完成！处理时间: ${result.processing_time?.toFixed(2) || "未知"}秒`);
          } else {
            throw new Error(result.error || "抠图处理失败");
          }
        } catch (error) {
          console.error("[抠图] 错误:", error);
          toast.error(error instanceof Error ? error.message : "抠图失败，请稍后重试");
          // 移除加载消息
          setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        } finally {
          console.log("[抠图] finally 块执行，重置 isProcessingRmbg");
          setIsProcessingRmbg(false);
        }
      };
      
      reader.onerror = () => {
        console.log("[抠图] reader.onerror 执行，重置 isProcessingRmbg");
        toast.error("图片读取失败");
        setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        setIsProcessingRmbg(false);
      };
      
      reader.readAsDataURL(blob);
    } catch (error) {
      console.error("[抠图] 错误:", error);
      console.log("[抠图] 外层 catch 执行，重置 isProcessingRmbg");
      toast.error(error instanceof Error ? error.message : "抠图失败，请稍后重试");
      setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
      setIsProcessingRmbg(false);
    }
  };

  // 处理图片去水印
  const handleImageWatermarkRemove = async (imageUrl: string) => {
    // 防止重复点击
    if (isProcessingEnhance || isProcessingRmbg || isProcessingExtend || isProcessingWatermarkRemove) {
      toast.info("正在处理中，请稍候...");
      return;
    }
    
    setIsProcessingWatermarkRemove(true);
    const messageId = generateUUID();
    
    // 创建临时加载消息
    const loadingMessage: ChatMessage = {
      id: messageId,
      role: "assistant",
      parts: [{ type: "text", text: "正在去水印..." }],
      createdAt: new Date().toISOString(),
    } as ChatMessage;
    
    setMessages((prev) => [...prev, loadingMessage]);
    
    // 延迟滚动到底部，确保DOM已更新
    setTimeout(() => {
      const messagesContainer = document.querySelector('[role="log"]');
      if (messagesContainer) {
        messagesContainer.scrollTo({
          top: messagesContainer.scrollHeight,
          behavior: "smooth",
        });
      }
    }, 100);

    try {
      // 调用去水印API
      const watermarkRemoveResponse = await fetch("/api/watermark-remove", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          image_url: imageUrl,
        }),
      });

      if (!watermarkRemoveResponse.ok) {
        const error = await watermarkRemoveResponse.json();
        throw new Error(error.error || "去水印处理失败");
      }

      const result = await watermarkRemoveResponse.json();

      if (result.success && result.original_url) {
        // 构造图片Markdown（使用与Gemini生成相同的格式）
        const imageMarkdown = `![thumb|||${result.original_url}|||2K](${result.thumbnail_url || result.original_url})`;
        
        // 创建最终消息（前端显示用）
        const finalMessage: ChatMessage = {
          id: messageId,
          role: "assistant",
          parts: [{ type: "text", text: imageMarkdown }],
          createdAt: new Date().toISOString(),
        } as ChatMessage;
        
        setMessages((prev) => {
          const filtered = prev.filter((msg) => msg.id !== messageId);
          return [...filtered, finalMessage];
        });

        // 保存消息到数据库
        try {
          const saveResponse = await fetch("/api/messages", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({
              chatId: id,
              message: {
                id: messageId,
                role: "assistant",
                parts: [{ type: "text", text: imageMarkdown }],
              },
            }),
          });
          
          if (!saveResponse.ok) {
            console.error("[Chat] Failed to save message:", await saveResponse.text());
          }
        } catch (saveError) {
          console.error("[Chat] Failed to save message:", saveError);
        }
        
        toast.success(`去水印完成！处理时间: ${result.processing_time?.toFixed(2) || "未知"}秒`);
      } else {
        throw new Error(result.error || "去水印处理失败");
      }
    } catch (error) {
      console.error("[去水印] 错误:", error);
      toast.error(error instanceof Error ? error.message : "去水印失败，请稍后重试");
      // 移除加载消息
      setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
    } finally {
      setIsProcessingWatermarkRemove(false);
    }
  };

  // 处理图像拓展
  const handleImageExtend = async (imageUrl: string) => {
    // 防止重复点击
    if (isProcessingEnhance || isProcessingRmbg || isProcessingExtend) {
      toast.info("正在处理中，请稍候...");
      return;
    }
    
    setIsProcessingExtend(true);
    const messageId = generateUUID();
    
    // 创建临时加载消息
    const loadingMessage: ChatMessage = {
      id: messageId,
      role: "assistant",
      parts: [{ type: "text", text: "正在图像拓展..." }],
      metadata: {
        createdAt: new Date().toISOString(),
      },
    } as ChatMessage;
    
    setMessages((prev) => [...prev, loadingMessage]);
    
    // 延迟滚动到底部，确保DOM已更新
    setTimeout(() => {
      const messagesContainer = document.querySelector('[role="log"]');
      if (messagesContainer) {
        messagesContainer.scrollTo({
          top: messagesContainer.scrollHeight,
          behavior: "smooth",
        });
      }
    }, 100);
    
    try {
      // 获取图片并转换为Base64
      const response = await fetch(imageUrl);
      const blob = await response.blob();
      const reader = new FileReader();
      
      reader.onloadend = async () => {
        try {
          const base64Data = (reader.result as string).split(",")[1];
          
          // 调用图像拓展API
          const extendResponse = await fetch("/api/extend", {
            method: "POST",
            headers: {
              "Content-Type": "application/json",
            },
            body: JSON.stringify({
              image_base64: base64Data,
              prompt: "图片图像拓展处理",
            }),
          });

          if (!extendResponse.ok) {
            const error = await extendResponse.json();
            throw new Error(error.error || "图像拓展处理失败");
          }

          const result = await extendResponse.json();

          if (result.success && result.original_url) {
            // 构造图片Markdown（使用与Gemini生成相同的格式）
            const imageMarkdown = `![thumb|||${result.original_url}|||2K](${result.thumbnail_url || result.original_url})`;
            
            // 创建最终消息（前端显示用）
            const finalMessage: ChatMessage = {
              id: messageId,
              role: "assistant",
              parts: [{ type: "text", text: imageMarkdown }],
              metadata: {
                createdAt: new Date().toISOString(),
              },
            } as ChatMessage;
            
            // 更新消息
            setMessages((prev) => 
              prev.map((msg) => (msg.id === messageId ? finalMessage : msg))
            );
            
            // 滚动到底部，显示处理结果
            setTimeout(() => {
              const messagesContainer = document.querySelector('[role="log"]');
              if (messagesContainer) {
                messagesContainer.scrollTo({
                  top: messagesContainer.scrollHeight,
                  behavior: "smooth",
                });
              }
            }, 100);
            
            // 保存消息到数据库
            try {
              await fetch("/api/messages", {
                method: "POST",
                headers: {
                  "Content-Type": "application/json",
                },
                body: JSON.stringify({
                  chatId: id,
                  message: {
                    id: messageId,
                    role: "assistant",
                    parts: [{ type: "text", text: imageMarkdown }],
                    attachments: [],
                    createdAt: new Date().toISOString(),
                  },
                }),
              });
            } catch (saveError) {
              console.error("[Chat] Failed to save message:", saveError);
            }
            
            toast.success(`图像拓展完成！处理时间: ${result.processing_time?.toFixed(2) || "未知"}秒`);
          } else {
            throw new Error(result.error || "图像拓展处理失败");
          }
        } catch (error) {
          console.error("[图像拓展] 错误:", error);
          toast.error(error instanceof Error ? error.message : "图像拓展失败，请稍后重试");
          // 移除加载消息
          setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        } finally {
          console.log("[图像拓展] finally 块执行，重置 isProcessingExtend");
          setIsProcessingExtend(false);
        }
      };
      
      reader.onerror = () => {
        console.log("[图像拓展] reader.onerror 执行，重置 isProcessingExtend");
        toast.error("图片读取失败");
        setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
        setIsProcessingExtend(false);
      };
      
      reader.readAsDataURL(blob);
    } catch (error) {
      console.error("[图像拓展] 错误:", error);
      console.log("[图像拓展] 外层 catch 执行，重置 isProcessingExtend");
      toast.error(error instanceof Error ? error.message : "图像拓展失败，请稍后重试");
      setMessages((prev) => prev.filter((msg) => msg.id !== messageId));
      setIsProcessingExtend(false);
    }
  };

  // 处理角度编辑完成
  const handleImageAngleEdit = async (resultUrl: string) => {
    const messageId = generateUUID();
    
    // 构造图片Markdown（使用与其他处理功能相同的格式）
    const imageMarkdown = `![thumb|||${resultUrl}|||2K](${resultUrl})`;
    
    // 创建最终消息
    const finalMessage: ChatMessage = {
      id: messageId,
      role: "assistant",
      parts: [{ type: "text", text: imageMarkdown }],
      metadata: {
        createdAt: new Date().toISOString(),
      },
    } as ChatMessage;
    
    // 添加消息
    setMessages((prev) => [...prev, finalMessage]);
    
    // 滚动到底部
    setTimeout(() => {
      const messagesContainer = document.querySelector('[role="log"]');
      if (messagesContainer) {
        messagesContainer.scrollTo({
          top: messagesContainer.scrollHeight,
          behavior: "smooth",
        });
      }
    }, 100);
    
    // 保存消息到数据库
    try {
      await fetch("/api/messages", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          chatId: id,
          message: {
            id: messageId,
            role: "assistant",
            parts: [{ type: "text", text: imageMarkdown }],
            attachments: [],
            createdAt: new Date().toISOString(),
          },
        }),
      });
    } catch (saveError) {
      console.error("[Chat] Failed to save angle edit message:", saveError);
    }
  };

  useAutoResume({
    autoResume,
    initialMessages,
    resumeStream,
    setMessages,
  });

  // 🆕 合并消息：初始消息 + useChat 消息 + appendedMessages
  // 确保历史消息不会因为 useChat 内部状态重置而丢失
  const mergedMessages = useMemo(() => {
    // 使用 Map 进行去重，以 ID 为键
    const messageMap = new Map<string, ChatMessage>();
    
    // 1. 首先添加初始消息（历史记录）
    initialMessagesRef.current.forEach(m => {
      messageMap.set(m.id, m);
    });
    
    // 2. 然后添加 useChat 的当前消息（会覆盖相同 ID 的旧消息）
    messages.forEach(m => {
      messageMap.set(m.id, m);
    });
    
    // 3. 最后添加 appendedMessages（data-appendMessage 的消息）
    appendedMessages.forEach(m => {
      if (!messageMap.has(m.id)) {
        messageMap.set(m.id, m);
      }
    });
    
    // 按创建时间排序
    const result = Array.from(messageMap.values()).sort((a, b) => {
      const timeA = (a as any).createdAt ? new Date((a as any).createdAt).getTime() : 0;
      const timeB = (b as any).createdAt ? new Date((b as any).createdAt).getTime() : 0;
      return timeA - timeB;
    });
    
    console.log("[Chat] Merged messages:", result.length, "(initial:", initialMessagesRef.current.length, ", current:", messages.length, ", appended:", appendedMessages.length, ")");
    return result;
  }, [messages, appendedMessages]);

  return (
    <>
      <div className="overscroll-behavior-contain flex h-dvh min-w-0 touch-pan-y flex-col bg-background">
        <ChatHeader
          chatId={id}
          isReadonly={isReadonly}
          selectedVisibilityType={initialVisibilityType}
        />

        <Messages
          chatId={id}
          isArtifactVisible={isArtifactVisible}
          isReadonly={isReadonly}
          messages={mergedMessages}
          regenerate={regenerate}
          sendMessage={sendMessage}
          selectedModelId={currentModelId}
          setMessages={setMessages}
          status={status}
          votes={votes}
          onImageEdit={handleImageEdit}
          onDrawingComplete={handleDrawingComplete}
          onImageEnhance={handleImageEnhance}
          onImageRmbg={handleImageRmbg}
          onImageExtend={handleImageExtend}
          onImageAngleEdit={handleImageAngleEdit}
          onImageWatermarkRemove={handleImageWatermarkRemove}
          isProcessingEnhance={isProcessingEnhance}
          isProcessingRmbg={isProcessingRmbg}
          isProcessingExtend={isProcessingExtend}
          isProcessingAngleEdit={isProcessingAngleEdit}
          isProcessingWatermarkRemove={isProcessingWatermarkRemove}
          pendingGeneration={pendingGeneration}
          imageCount={imageParams?.imageCount || 1}
          isGeneratingImageFlag={isGeneratingImageFlag}
          imageGenerationPhase={imageGenerationPhase}
          imageGenerationStartedAt={imageGenerationStartedAt}
        />

        <div className="sticky bottom-0 z-1 mx-auto w-full max-w-4xl bg-background px-2 pb-3 md:px-4 md:pb-4">
          {!isReadonly && (
            <MultimodalInput
              attachments={attachments}
              chatId={id}
              input={input}
              messages={mergedMessages}
              onModelChange={setCurrentModelId}
              selectedModelId={currentModelId}
              selectedVisibilityType={visibilityType}
              sendMessage={sendMessage}
              setAttachments={setAttachments}
              setInput={setInput}
              setMessages={setMessages}
              status={status}
              stop={stop}
              usage={usage}
              isVideoModel={isVideoModel}
              videoModelName={currentModel?.displayName}
              videoParams={videoParams}
              onVideoParamsChange={(params) => {
                setVideoParams(params);
                console.log("[Chat] Video params updated:", params);
              }}
              isImageModel={isImageModel}
              imageModelName={currentModel?.displayName}
              imageParams={imageParams}
              onImageParamsChange={handleImageParamsChange}
              imageProviderType={currentModel?.providerType}
            />
          )}
        </div>
      </div>

      <Artifact
        attachments={attachments}
        chatId={id}
        input={input}
        isReadonly={isReadonly}
        messages={mergedMessages}
        regenerate={regenerate}
        selectedModelId={currentModelId}
        selectedVisibilityType={visibilityType}
        sendMessage={sendMessage}
        setAttachments={setAttachments}
        setInput={setInput}
        setMessages={setMessages}
        status={status}
        stop={stop}
        votes={votes}
      />

      <AlertDialog
        onOpenChange={setShowCreditCardAlert}
        open={showCreditCardAlert}
      >
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>启用 AI Gateway</AlertDialogTitle>
            <AlertDialogDescription>
              此应用需要
              {process.env.NODE_ENV === "production" ? "项目拥有者" : "你"}
              激活 Vercel AI Gateway。
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>取消</AlertDialogCancel>
            <AlertDialogAction
              onClick={() => {
                window.open(
                  "https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dadd-credit-card",
                  "_blank"
                );
                window.location.href = "/";
              }}
            >
              立即启用
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </>
  );
}