import type { RequestHandler } from './$types';
import { env } from 'process';

const NO_BODY_METHODS = new Set(['GET', 'HEAD', 'DELETE']);

async function proxy(event: Parameters<RequestHandler>[0]): Promise<Response> {
	const apiUrl = env.API_INTERNAL_URL || 'http://localhost:8080';
	const backendUrl = `${apiUrl}/api/${event.params.path}${event.url.search}`;

	const contentType = event.request.headers.get('Content-Type');
	const hasBody = !NO_BODY_METHODS.has(event.request.method);

	const response = await event.fetch(backendUrl, {
		method: event.request.method,
		headers: contentType ? { 'Content-Type': contentType } : {},
		body: hasBody ? await event.request.arrayBuffer() : undefined
	});

	const responseHeaders: Record<string, string> = {};
	const responseContentType = response.headers.get('Content-Type');
	if (responseContentType) responseHeaders['Content-Type'] = responseContentType;

	return new Response(response.body, {
		status: response.status,
		headers: responseHeaders
	});
}

export const GET: RequestHandler = (event) => proxy(event);
export const POST: RequestHandler = (event) => proxy(event);
export const PUT: RequestHandler = (event) => proxy(event);
export const PATCH: RequestHandler = (event) => proxy(event);
export const DELETE: RequestHandler = (event) => proxy(event);