import { json } from '@sveltejs/kit';
import type { RequestHandler } from './$types';
import { requireAdmin } from '$lib/server/middleware/authorize.js';
import { getBackupFilePath } from '$lib/server/services/backupService.js';
import { error } from '$lib/server/utils/response.js';
import fs from 'node:fs';
import path from 'node:path';
import { Readable } from 'node:stream';

/**
 * GET /api/admin/backups/:filename/download — Download a backup file (streamed).
 */
export const GET: RequestHandler = async (event) => {
	requireAdmin(event);
	const { filename } = event.params;

	const filePath = getBackupFilePath(filename);
	if (!filePath) {
		return json(error('Backup not found'), { status: 404 });
	}

	const stats = fs.statSync(filePath);
	const stream = fs.createReadStream(filePath);

	return new Response(Readable.toWeb(stream) as ReadableStream, {
		status: 200,
		headers: {
			'Content-Type': 'application/octet-stream',
			'Content-Disposition': `attachment; filename="${path.basename(filePath)}"`,
			'Content-Length': String(stats.size)
		}
	});
};