"use client";

import { useChat } from "@ai-sdk/react";
import { DefaultChatTransport } from "ai";
import { useRouter, useSearchParams } from "next/navigation";
import { useEffect, 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 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 "@/components/toast";
import type { VisibilityType } from "@/components/visibility-selector";
import type { VideoGenerationParams } from "@/components/video-params-bar";
import type { ImageGenerationParams } from "@/components/image-params-bar";

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,
  });

  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);
  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) {
        setImageParams(JSON.parse(saved));
      }
    } catch (e) {
      console.error("Failed to load image params:", e);
    }
  }, []);

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

  // 🆕 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) {
      // 强制更新一次 imageParams 以触发重新渲染
      setImageParams(prev => ({...prev}));
      console.log("[Chat] 图片模型已激活，触发参数更新");
    }
  }, [isImageModel]);

  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 {
          // dataPart.data 是 JSON 字符串
          const messageData = typeof dataPart.data === 'string' 
            ? JSON.parse(dataPart.data) 
            : dataPart.data;
            
          console.log("[Chat] Received appendMessage:", messageData);
          
          setMessages((prevMessages) => {
            if (prevMessages.some(m => m.id === messageData.id)) {
              return prevMessages;
            }
            
            // 构造 ChatMessage 对象
            // 注意：这里需要确保符合 ChatMessage 类型定义
            const newMessage: any = {
              id: messageData.id,
              role: messageData.role,
              content: messageData.parts?.[0]?.text || "",
              createdAt: new Date(),
              parts: messageData.parts || [],
              attachments: [],
            };
            
            return [...prevMessages, newMessage];
          });
        } catch (e) {
          console.error("[Chat] Failed to parse data-appendMessage:", e);
        }
      }
    },
    onFinish: () => {
      mutate(unstable_serialize(getChatHistoryPaginationKey));
    },
    onError: (error) => {
      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({
            type: "error",
            description: error.message,
          });
        }
      }
    },
  });

  // 调试：监控聊天状态变化
  useEffect(() => {
    console.log(`[Chat] Status: ${status}`);
  }, [status]);

  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]);

  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：");
  };

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

  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={messages}
          regenerate={regenerate}
          sendMessage={sendMessage}
          selectedModelId={initialChatModel}
          setMessages={setMessages}
          status={status}
          votes={votes}
          onImageEdit={handleImageEdit}
        />

        <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={messages}
              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}
            />
          )}
        </div>
      </div>

      <Artifact
        attachments={attachments}
        chatId={id}
        input={input}
        isReadonly={isReadonly}
        messages={messages}
        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>
    </>
  );
}