import { NextRequest, NextResponse } from "next/server";
import { writeFile, mkdir } from "fs/promises";
import { join } from "path";
import { existsSync } from "fs";

const UPLOAD_DIR = join(process.cwd(), "uploads");
const MAX_FILE_SIZE = 10 * 1024 * 1024; // 10MB

// Ensure upload directory exists
async function ensureUploadDir() {
    if (!existsSync(UPLOAD_DIR)) {
        await mkdir(UPLOAD_DIR, { recursive: true });
    }
}

export async function POST(request: NextRequest) {
    try {
        const formData = await request.formData();
        const file = formData.get("file") as File;

        if (!file) {
            return NextResponse.json(
                { error: "No file provided" },
                { status: 400 }
            );
        }

        // Check file size
        if (file.size > MAX_FILE_SIZE) {
            return NextResponse.json(
                { error: "File too large. Maximum size is 10MB" },
                { status: 400 }
            );
        }

        // Ensure upload directory exists
        await ensureUploadDir();

        // Generate unique file ID
        const fileId = crypto.randomUUID();
        const bytes = await file.arrayBuffer();
        const buffer = Buffer.from(bytes);

        // Save encrypted file
        const filePath = join(UPLOAD_DIR, fileId);
        await writeFile(filePath, buffer);

        return NextResponse.json({
            fileId,
            size: file.size,
            name: file.name,
            type: file.type,
        });
    } catch (error) {
        console.error("Upload error:", error);
        return NextResponse.json(
            { error: "Upload failed" },
            { status: 500 }
        );
    }
}