interface ModelsDevCache {
    data: any;
    etag: string | null;
    lastFetched: number;
}

let modelsDevCache: ModelsDevCache = {
    data: null,
    etag: null,
    lastFetched: 0,
};

const MODELS_DEV_URL = 'https://models.dev/api.json';
const CACHE_TTL = 60 * 1000; // 60 seconds

export async function getModelsDevData(): Promise<any> {
    const now = Date.now();

    if (modelsDevCache.data &&
        (now - modelsDevCache.lastFetched < CACHE_TTL)) {
        return modelsDevCache.data;
    }

    try {
        const headers: HeadersInit = {};
        if (modelsDevCache.etag) {
            headers['If-None-Match'] = modelsDevCache.etag;
        }

        const response = await fetch(MODELS_DEV_URL, { headers });

        if (response.status === 304) {
            modelsDevCache.lastFetched = now;
            return modelsDevCache.data;
        }

        const newData = await response.json();
        const newEtag = response.headers.get('ETag') || null;

        modelsDevCache = {
            data: newData,
            etag: newEtag,
            lastFetched: now,
        };

        return newData;
    } catch (error) {
        console.error('Error fetching models.dev:', error);
        return modelsDevCache.data || {};
    }
}