import { NextRequest, NextResponse } from "next/server";
import { getSystemSetting } from "@/lib/db/queries";
import { auth } from "@/app/(auth)/auth";
import { uploadFile } from "@/lib/storage/service";
import { db } from "@/lib/db";
import { generatedImage } from "@/lib/db/schema";

/**
 * 压缩图片生成缩略图（使用 sharp）
 */
async function createThumbnail(buffer: Buffer, mimeType: string): Promise<Buffer> {
  try {
    const sharp = await import("sharp");
    
    // 创建缩略图（宽度 500px，高度按比例，质量 80%）
    const thumbnailBuffer = await sharp.default(buffer)
      .resize(500, null, {
        fit: "inside",
        withoutEnlargement: true,
      })
      .png({ quality: 80 }) // PNG格式保持透明背景
      .toBuffer();
    
    console.log(`[RMBG] Thumbnail created, size: ${thumbnailBuffer.length} bytes (original: ${buffer.length} bytes)`);
    return thumbnailBuffer;
  } catch (error) {
    console.error("[RMBG] Failed to create thumbnail:", error);
    // 如果失败，返回原图
    return buffer;
  }
}

/**
 * 将 base64 图片上传到 S3，返回缩略图和原图的 URL
 */
async function uploadBase64ToS3(base64Data: string, mimeType: string = "image/png"): Promise<{ thumbnail: string; original: string }> {
  try {
    // 解析 base64 数据
    const buffer = Buffer.from(base64Data, "base64");
    
    // 生成文件名
    const ext = mimeType.split("/")[1] || "png";
    const timestamp = Date.now();
    const randomStr = Math.random().toString(36).slice(2, 8);
    const thumbnailFilename = `rmbg-thumb-${timestamp}-${randomStr}.${ext}`;
    const originalFilename = `rmbg-orig-${timestamp}-${randomStr}.${ext}`;
    
    console.log(`[RMBG] Original size: ${buffer.length} bytes`);
    
    // 生成缩略图
    const thumbnailBuffer = await createThumbnail(buffer, mimeType);
    
    // 转换为 ArrayBuffer
    const thumbnailArrayBuffer = thumbnailBuffer.buffer.slice(
      thumbnailBuffer.byteOffset, 
      thumbnailBuffer.byteOffset + thumbnailBuffer.byteLength
    ) as ArrayBuffer;
    const originalArrayBuffer = buffer.buffer.slice(
      buffer.byteOffset, 
      buffer.byteOffset + buffer.byteLength
    ) as ArrayBuffer;
    
    // 并行上传缩略图和原图到 S3
    console.log(`[RMBG] Uploading thumbnail and original to S3...`);
    const [thumbnailResult, originalResult] = await Promise.all([
      uploadFile(thumbnailFilename, thumbnailArrayBuffer),
      uploadFile(originalFilename, originalArrayBuffer),
    ]);
    
    console.log(`[RMBG] Uploaded to S3:`);
    console.log(`  - Thumbnail: ${thumbnailResult.url}`);
    console.log(`  - Original: ${originalResult.url}`);
    
    return {
      thumbnail: thumbnailResult.url,
      original: originalResult.url,
    };
  } catch (error) {
    console.error("[RMBG] Failed to upload to S3:", error);
    throw new Error(`图片上传到存储桶失败: ${error instanceof Error ? error.message : "未知错误"}。请检查系统设置中的存储配置。`);
  }
}

/**
 * 抠图API路由
 * 从数据库读取RMBG API配置，调用外部API进行抠图处理
 * 将处理后的图片上传到S3并保存到数据库
 */
export async function POST(request: NextRequest) {
  try {
    // 0. 获取用户会话
    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: "未授权，请先登录" },
        { status: 401 }
      );
    }

    const userId = session.user.id;
    // 1. 从数据库获取RMBG API配置
    const rmbgConfig = await getSystemSetting({ key: "rmbg_api_config" });
    
    if (!rmbgConfig || !rmbgConfig.value) {
      return NextResponse.json(
        { error: "抠图API配置未设置，请在系统设置中配置" },
        { status: 400 }
      );
    }

    const config = rmbgConfig.value as {
      apiUrl?: string;
      apiKey?: string;
    };

    if (!config.apiUrl) {
      return NextResponse.json(
        { error: "抠图API地址未配置" },
        { status: 400 }
      );
    }

    // 2. 获取请求体（Base64图片或FormData）
    const contentType = request.headers.get("content-type") || "";
    
    let imageBase64: string;
    let prompt = ""; // 用户提示词（可选）
    let chatId: string | null = null; // 聊天ID（可选）
    let messageId: string | null = null; // 消息ID（可选）
    
    if (contentType.includes("application/json")) {
      // JSON格式：Base64图片
      const body = await request.json();
      imageBase64 = body.image_base64;
      prompt = body.prompt || "抠图处理";
      chatId = body.chatId || null;
      messageId = body.messageId || null;
      
      if (!imageBase64) {
        return NextResponse.json(
          { error: "缺少image_base64参数" },
          { status: 400 }
        );
      }
    } else if (contentType.includes("multipart/form-data")) {
      // FormData格式：文件上传
      const formData = await request.formData();
      const file = formData.get("file") as File;
      
      if (!file) {
        return NextResponse.json(
          { error: "缺少file参数" },
          { status: 400 }
        );
      }

      // 将文件转换为Base64
      const arrayBuffer = await file.arrayBuffer();
      const buffer = Buffer.from(arrayBuffer);
      imageBase64 = buffer.toString("base64");
      prompt = (formData.get("prompt") as string) || "抠图处理";
      chatId = (formData.get("chatId") as string) || null;
      messageId = (formData.get("messageId") as string) || null;
    } else {
      return NextResponse.json(
        { error: "不支持的Content-Type，请使用application/json或multipart/form-data" },
        { status: 400 }
      );
    }

    // 3. 调用RMBG API
    const apiUrl = config.apiUrl.endsWith("/")
      ? `${config.apiUrl}rmbg/base64`
      : `${config.apiUrl}/rmbg/base64`;

    const requestBody = {
      image_base64: imageBase64,
    };

    const headers: HeadersInit = {
      "Content-Type": "application/json",
    };

    // 如果配置了API Key，添加到请求头（根据RMBG API文档要求使用X-API-Key）
    if (config.apiKey) {
      headers["X-API-Key"] = config.apiKey;
    }

    const startTime = Date.now();
    let response: Response;
    
    try {
      // 添加超时控制（30秒）
      const controller = new AbortController();
      const timeoutId = setTimeout(() => controller.abort(), 30000);
      
      response = await fetch(apiUrl, {
        method: "POST",
        headers,
        body: JSON.stringify(requestBody),
        signal: controller.signal,
      });
      
      clearTimeout(timeoutId);
    } catch (fetchError) {
      const processingTime = (Date.now() - startTime) / 1000;
      console.error("[RMBG API] 网络请求失败:", {
        error: fetchError,
        apiUrl,
        processingTime,
      });
      
      // 检查是否是网络连接错误
      if (fetchError instanceof Error) {
        // 检查超时错误
        if (fetchError.name === 'AbortError') {
          return NextResponse.json(
            { 
              error: "抠图API请求超时",
              detail: "请求超过30秒未响应，请检查API服务器状态或网络连接",
            },
            { status: 504 }
          );
        }
        
        // 检查错误消息和cause中的网络错误
        const errorMessage = fetchError.message || '';
        const errorCause = (fetchError as any).cause;
        const causeMessage = errorCause?.message || '';
        const causeCode = errorCause?.code || '';
        
        // 检查各种网络连接错误
        if (errorMessage.includes('EHOSTUNREACH') || 
            errorMessage.includes('ENOTFOUND') ||
            errorMessage.includes('ECONNREFUSED') ||
            errorMessage.includes('No route to host') ||
            causeMessage.includes('EHOSTUNREACH') ||
            causeMessage.includes('ENOTFOUND') ||
            causeMessage.includes('ECONNREFUSED') ||
            causeMessage.includes('No route to host') ||
            causeCode === 'EHOSTUNREACH' ||
            causeCode === 'ENOTFOUND' ||
            causeCode === 'ECONNREFUSED') {
          return NextResponse.json(
            { 
              error: "无法连接到抠图API服务器",
              detail: `服务器无法访问 ${apiUrl}，请检查：\n1. API服务器是否在线\n2. 网络连接是否正常\n3. 防火墙设置是否正确\n4. 端口8000是否已开放`,
            },
            { status: 503 }
          );
        }
      }
      
      return NextResponse.json(
        { 
          error: "抠图API请求失败",
          detail: fetchError instanceof Error ? fetchError.message : "未知网络错误",
        },
        { status: 500 }
      );
    }

    const processingTime = (Date.now() - startTime) / 1000;

    if (!response.ok) {
      const errorText = await response.text();
      console.error("[RMBG API] 请求失败:", {
        status: response.status,
        statusText: response.statusText,
        error: errorText,
        apiUrl,
      });
      
      return NextResponse.json(
        { 
          error: "抠图API请求失败",
          detail: errorText || response.statusText,
        },
        { status: response.status }
      );
    }

    const result = await response.json();

    // 4. 处理返回结果
    if (!result.success || !result.image_base64) {
      return NextResponse.json(
        { error: "抠图处理失败", detail: result.detail || "未知错误" },
        { status: 500 }
      );
    }

    // 5. 上传处理后的图片到S3存储桶
    let thumbnailUrl: string;
    let originalUrl: string;
    
    try {
      const uploadResult = await uploadBase64ToS3(result.image_base64, "image/png");
      thumbnailUrl = uploadResult.thumbnail;
      originalUrl = uploadResult.original;
      console.log(`[RMBG] ✅ Images uploaded to S3 successfully`);
    } catch (uploadError) {
      console.error("[RMBG] ❌ Failed to upload to S3:", uploadError);
      return NextResponse.json(
        { 
          error: "图片上传到存储桶失败", 
          detail: uploadError instanceof Error ? uploadError.message : "未知错误" 
        },
        { status: 500 }
      );
    }

    // 6. 保存图片记录到数据库（相册和生图记录）
    try {
      const [savedImage] = await db.insert(generatedImage).values({
        userId,
        chatId: chatId || null,
        messageId: messageId || null,
        thumbnailUrl,
        originalUrl,
        imageSize: "2K", // 默认尺寸
        prompt: prompt || "抠图处理",
        modelId: "rmbg-2.0", // 标记为抠图处理
      }).returning();
      console.log(`[RMBG] ✅ 图片已保存到相册和生图记录，ID: ${savedImage.id}`);
    } catch (dbError) {
      console.error("[RMBG] ❌ 保存到数据库失败:", dbError);
      // 数据库保存失败时仍然返回成功，但记录错误（图片已上传到S3，用户可以访问）
      // 如果希望严格保证数据一致性，可以取消注释下面的代码来返回错误
      // return NextResponse.json(
      //   { 
      //     error: "图片已处理但保存到相册失败", 
      //     detail: dbError instanceof Error ? dbError.message : "未知错误" 
      //   },
      //   { status: 500 }
      // );
    }

    // 7. 返回结果（包含S3 URL和Base64，前端可以选择使用）
    return NextResponse.json({
      success: true,
      image_base64: result.image_base64, // 保留Base64用于前端立即显示
      thumbnail_url: thumbnailUrl, // S3缩略图URL
      original_url: originalUrl, // S3原图URL
      processing_time: result.processing_time || processingTime,
    });
  } catch (error) {
    console.error("[RMBG API] 处理错误:", error);
    return NextResponse.json(
      { error: "服务器内部错误", detail: error instanceof Error ? error.message : "未知错误" },
      { status: 500 }
    );
  }
}