import { NextRequest, NextResponse } from "next/server";

import { auth } from "@/app/(auth)/auth";
import {
  executeRmbgJob,
  fetchImageBufferFromUrl,
  RmbgServiceError,
} from "@/lib/ai/rmbg/service";

export const runtime = "nodejs";
export const maxDuration = 60;

export async function POST(request: NextRequest) {
  try {
    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json({ error: "未授权，请先登录" }, { status: 401 });
    }

    const contentType = request.headers.get("content-type") || "";

    let imageBuffer: Buffer;
    let imageBase64: string | undefined;
    let prompt = "抠图处理";
    let chatId: string | null = null;
    let messageId: string | null = null;
    let skipGallerySave = false;
    let sourceImageUrl: string | null = null;

    if (contentType.includes("application/json")) {
      const body = await request.json();
      prompt = body.prompt || "抠图处理";
      chatId = body.chatId || null;
      messageId = body.messageId || null;
      skipGallerySave = body.skipGallerySave === true || body.skip_gallery_save === 1;

      const imageUrl = body.imageUrl || body.image_url;
      const explicitSourceImageUrl = body.sourceImageUrl || body.source_image_url;

      if (imageUrl) {
        sourceImageUrl = String(imageUrl);
        imageBuffer = await fetchImageBufferFromUrl(sourceImageUrl);
      } else if (body.image_base64) {
        imageBase64 = String(body.image_base64);
        imageBuffer = Buffer.from(imageBase64, "base64");
        if (explicitSourceImageUrl) {
          sourceImageUrl = String(explicitSourceImageUrl);
        }
      } else {
        return NextResponse.json(
          { error: "缺少 imageUrl 或 image_base64 参数" },
          { status: 400 }
        );
      }
    } else if (contentType.includes("multipart/form-data")) {
      const formData = await request.formData();
      const file = formData.get("file") as File | null;

      if (!file) {
        return NextResponse.json({ error: "缺少file参数" }, { status: 400 });
      }

      const arrayBuffer = await file.arrayBuffer();
      imageBuffer = Buffer.from(arrayBuffer);
      imageBase64 = imageBuffer.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;
      skipGallerySave =
        formData.get("skipGallerySave") === "true" || formData.get("skip_gallery_save") === "1";
      sourceImageUrl =
        (formData.get("sourceImageUrl") as string) ||
        (formData.get("source_image_url") 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 }
      );
    }

    const result = await executeRmbgJob({
      userId: session.user.id,
      imageBuffer,
      imageBase64,
      prompt,
      chatId,
      messageId,
      skipGallerySave,
      sourceImageUrl,
    });

    return NextResponse.json({
      success: true,
      ...result,
    });
  } catch (error) {
    if (error instanceof RmbgServiceError) {
      return NextResponse.json(
        {
          error: error.message,
          detail: error.detail || error.message,
        },
        { status: error.status }
      );
    }

    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 }
    );
  }
}