import { NextResponse } from "next/server";
import { z } from "zod";

import { auth } from "@/app/(auth)/auth";
import { uploadFile } from "@/lib/storage/service";

// Use Blob instead of File since File is not available in Node.js environment
const FileSchema = z.object({
  file: z
    .instanceof(Blob)
    .refine((file) => file.size <= 8 * 1024 * 1024, {
      message: "File size should be less than 8MB",
    })
    // Update the file type based on the kind of files you want to accept
    .refine((file) => ["image/jpeg", "image/png", "image/webp"].includes(file.type), {
      message: "File type should be JPEG, PNG or WebP",
    }),
});

export async function POST(request: Request) {
  console.log("[Upload API] Received upload request");
  
  const session = await auth();

  if (!session) {
    console.log("[Upload API] Unauthorized - no session");
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  if (request.body === null) {
    console.log("[Upload API] Request body is empty");
    return new Response("Request body is empty", { status: 400 });
  }

  try {
    const formData = await request.formData();
    const file = formData.get("file") as Blob;

    console.log("[Upload API] FormData received, file exists:", !!file);

    if (!file) {
      console.log("[Upload API] No file in FormData");
      return NextResponse.json({ error: "No file uploaded" }, { status: 400 });
    }

    console.log("[Upload API] File info:", {
      type: file.type,
      size: file.size,
      sizeInMB: (file.size / 1024 / 1024).toFixed(2) + "MB"
    });

    const validatedFile = FileSchema.safeParse({ file });

    if (!validatedFile.success) {
      const errorMessage = validatedFile.error.errors
        .map((error) => error.message)
        .join(", ");

      console.log("[Upload API] Validation failed:", errorMessage);
      return NextResponse.json({ error: errorMessage }, { status: 400 });
    }

    // Get filename from formData since Blob doesn't have name property
    const filename = (formData.get("file") as File).name;
    console.log("[Upload API] Filename:", filename);
    
    const fileBuffer = await file.arrayBuffer();
    console.log("[Upload API] File buffer size:", fileBuffer.byteLength);

    try {
      // 使用统一的存储服务（支持数据库配置的 S3、环境变量 S3 或 Vercel Blob）
      const data = await uploadFile(filename, fileBuffer);

      console.log("[Upload API] Upload successful:", data.url);
      return NextResponse.json(data);
    } catch (_error) {
      console.error("[Upload API] Upload failed:", _error);
      return NextResponse.json({ 
        error: "Upload failed", 
        details: _error instanceof Error ? _error.message : String(_error)
      }, { status: 500 });
    }
  } catch (_error) {
    console.error("[Upload API] Request processing failed:", _error);
    return NextResponse.json(
      { 
        error: "Failed to process request",
        details: _error instanceof Error ? _error.message : String(_error)
      },
      { status: 500 }
    );
  }
}