import crypto from 'node:crypto';

import type { Handle, HandleServerError } from '@sveltejs/kit';
import { redirect } from '@sveltejs/kit';

import { resolve } from '$app/paths';

import {
	ForbiddenError,
	isAppError,
	logger as rootLogger,
	NotFoundError,
	runWithContext,
	server,
	serverLogger as log,
	UnauthorizedError,
	ValidationError,
} from '$lib/server';
import type { User } from '$lib/types/user';

const LOGIN = resolve('/auth/login');
const WORKSPACE_RESOURCES = resolve('/api/workspaces');

const ready = server.init();

const shutdown = async (signal: string) => {
	log.info(`[${signal}] Shutting down...`);
	await server.shutdown();
	rootLogger.close();
	process.exit(0);
};

process.once('SIGTERM', () => shutdown('SIGTERM'));
process.once('SIGINT', () => shutdown('SIGINT'));

const handle: Handle = async ({ event, resolve: resolveRequest }) => {
	await ready;

	const requestId = crypto.randomUUID();
	event.locals.requestId = requestId;

	return runWithContext({ requestId }, async () => {
		const auth = server.auth;
		let user: User | undefined;
		if (auth) {
			const token = event.cookies.get('session');
			user = token ? await auth.verifyToken(token) : undefined;
			if (!user && event.url.pathname !== LOGIN) {
				redirect(302, LOGIN);
			}
		} else {
			user = {
				id: 'admin',
				name: 'Admin',
				email: 'admin@locostack.com',
				workspaces: ['*'],
			};
		}
		event.locals.user = user || null;

		const { pathname } = event.url;
		if (pathname.startsWith(WORKSPACE_RESOURCES) && pathname !== WORKSPACE_RESOURCES) {
			if (!user) {
				throw new UnauthorizedError('Authentication required');
			}
			const workspaceId = event.params.workspaceId;
			if (workspaceId === undefined) {
				throw new ValidationError('Workspace ID is required');
			}
			if (!user.workspaces.includes(workspaceId) && !user.workspaces.includes('*')) {
				throw new ForbiddenError('User does not have access to this workspace');
			}
			const workspace = server.ws.list().find((ws) => ws.id === workspaceId);
			if (!workspace) {
				throw new NotFoundError('Workspace not found');
			}
			event.locals.workspaceId = workspaceId;
			event.locals.workspace = workspace;
		} else {
			event.locals.workspaceId = event.cookies.get('workspaceId') || null;
		}
		return resolveRequest(event);
	});
};

/**
 * Catches any error that escapes a load function, action, or endpoint.
 * AppErrors are surfaced with their code and message; unexpected errors
 * are logged and replaced with a generic message so internals are not leaked.
 */
const handleError: HandleServerError = ({ error, event }) => {
	const requestId = event.locals.requestId;

	if (isAppError(error)) {
		log.warn('Application error', {
			code: error.code,
			status: error.statusCode,
			message: error.message,
			path: event.url.pathname,
			requestId,
		});
		return { code: error.code, message: error.message };
	}

	log.error('Unexpected server error', { err: error, path: event.url.pathname, requestId });
	return { code: 'INTERNAL_ERROR', message: 'An unexpected error occurred.' };
};

export { handle, handleError };