import { NextRequest, NextResponse } from 'next/server'
import fs from 'fs/promises'
import path from 'path'
import env from '@/lib/env';
import resolveFilePath from '@/lib/file';

// 白名单：允许访问的文件扩展名
const allowedExtensions = ['.html', '.js', '.css', '.json', '.png', '.jpg', '.jpeg', '.gif', '.svg'];

const basePath = path.join(process.cwd(), env('STATIC_FILE_PATH'))

export async function GET(req: NextRequest,
  { params }: { params: Promise<{ path?: string[] }> }
) {
  const fileseg = (await params).path

  const filepath = resolveFilePath(fileseg, basePath, allowedExtensions, ['index.html'])

  if (filepath === null) {
    return NextResponse.json({ message: 'File not found' }, { status: 404 })
  }
  
  try {
    // 获取文件扩展名以确定 MIME 类型
    const extname = path.extname(filepath).toLowerCase();
    if (!allowedExtensions.includes(extname)) {
      return NextResponse.json({ error: 'Forbidden file type' }, { status: 403 });
    }
      // 设置响应头
    let contentType = 'text/plain';
    switch (extname) {
      case '.html':
        contentType = 'text/html';
        break;
      case '.js':
        contentType = 'text/javascript';
        break;
      case '.css':
        contentType = 'text/css';
        break;
      case '.json':
        contentType = 'application/json';
        break;
      case '.png':
        contentType = 'image/png';
        break;
      case '.jpg':
      case '.jpeg':
        contentType = 'image/jpeg';
        break;
      case '.gif':
        contentType = 'image/gif';
        break;
      case '.svg':
        contentType = 'image/svg+xml';
        break;
      default:
        contentType = 'text/plain';
    }
    const responseHeaders = new Headers();
    responseHeaders.set('Content-Type', contentType);

    // 返回文件内容
    return new NextResponse(await fs.readFile(filepath), { status: 200, headers: responseHeaders });
  } catch (err) {
    console.error(err);
    return NextResponse.json({ error: 'Internal Server Error' }, { status: 500 });
  }
}