import { NextRequest, NextResponse } from 'next/server';
import fs from 'fs/promises';
import path from 'path';

export const runtime = 'nodejs';
export const dynamic = 'force-dynamic';

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url);
    const sessionId = searchParams.get('sessionId');
    const slideNumber = searchParams.get('slideNumber');

    if (!sessionId || !slideNumber) {
      return new NextResponse('Missing sessionId or slideNumber', { status: 400 });
    }

    const storageRoot = process.env.SPACE_ID ? '/data' : path.join(process.cwd(), 'data');
    const fileName = `slide_${slideNumber}.png`;
    const filePath = path.join(storageRoot, 'sessions', sessionId, fileName);

    const imageBuffer = await fs.readFile(filePath);

    return new NextResponse(imageBuffer, {
      status: 200,
      headers: {
        'Content-Type': 'image/png',
        'Cache-Control': 'public, max-age=31536000, immutable'
      }
    });
  } catch (error) {
    return new NextResponse('Image not found', { status: 404 });
  }
}