import { error } from '@sveltejs/kit';
import { browser } from '$app/environment';
import { config } from '$lib/stores/settings.svelte';

/**
 * Validates API key by making a request to the server props endpoint
 * Throws SvelteKit errors for authentication failures or server issues
 */
export async function validateApiKey(fetch: typeof globalThis.fetch): Promise<void> {
	if (!browser) {
		return;
	}

	try {
		const apiKey = config().apiKey;

		const headers: Record<string, string> = {
			'Content-Type': 'application/json'
		};

		if (apiKey) {
			headers.Authorization = `Bearer ${apiKey}`;
		}

		const response = await fetch('/props', { headers });

		if (!response.ok) {
			if (response.status === 401 || response.status === 403) {
				throw error(401, 'Access denied');
			} else if (response.status >= 500) {
				throw error(response.status, 'Server error - check if llama.cpp server is running');
			} else {
				throw error(response.status, `Server responded with status ${response.status}`);
			}
		}
	} catch (err) {
		// If it's already a SvelteKit error, re-throw it
		if (err && typeof err === 'object' && 'status' in err) {
			throw err;
		}

		// Network or other errors
		throw error(503, 'Cannot connect to server - check if llama.cpp server is running');
	}
}