hfService.js

const https = require('https');

const HF_API_URL = "https://huggingface.co/api/datasets/datalocalapi/truyen/tree/main?recursive=true";
const HF_ASSET_BASE = "https://huggingface.co/datasets/datalocalapi/truyen/resolve/main";

// Auto-refresh interval (15 minutes = 900000ms)
const REFRESH_INTERVAL_MS = 15 * 60 * 1000;

// Cache for HF data
let hfStoriesCache = {};
let isLoaded = false;
let lastFetchTime = null;
let refreshIntervalId = null;

/**
 * Fetch data from Hugging Face
 */
async function fetchHFData() {
    try {
        console.log('Fetching data from Hugging Face...');
        const response = await fetch(HF_API_URL);
        if (!response.ok) throw new Error(`HTTP error! status: ${response.status}`);

        const tree = await response.json();
        const processed = {};

        // Process tree structure
        for (const item of tree) {
            if (item.type !== 'file') continue;

            const parts = item.path.split('/');
            if (parts.length < 2) continue;

            const storyName = parts[0];

            if (!processed[storyName]) {
                processed[storyName] = {
                    id: storyName,
                    chapters: {},
                    cover: null
                };
            }

            // Check for cover image
            if (parts.length === 2 && /^thum\.(jpg|jpeg|png|webp|gif)$/i.test(parts[1])) {
                processed[storyName].cover = item.path; // Store relative path only
                continue;
            }

            // Check for chapter images
            if (parts.length >= 3) {
                const chapterName = parts[1];
                const fileName = parts[2];

                if (/\.(png|jpg|jpeg|webp|gif)$/i.test(fileName)) {
                    if (!processed[storyName].chapters[chapterName]) {
                        processed[storyName].chapters[chapterName] = [];
                    }
                    processed[storyName].chapters[chapterName].push({
                        name: fileName,
                        path: item.path // Store relative path
                    });
                }
            }
        }

        hfStoriesCache = processed;
        isLoaded = true;
        lastFetchTime = new Date();
        console.log(`[${lastFetchTime.toLocaleTimeString()}] Loaded ${Object.keys(processed).length} stories from Hugging Face`);
    } catch (error) {
        console.error('Failed to fetch HF data:', error);
    }
}

/**
 * Force refresh Hugging Face data
 */
async function forceRefreshHFData() {
    console.log('Force refreshing Hugging Face data...');
    await fetchHFData();
    return {
        success: isLoaded,
        storyCount: Object.keys(hfStoriesCache).length,
        lastFetchTime: lastFetchTime
    };
}

/**
 * Start auto-refresh interval
 */
function startAutoRefresh() {
    if (refreshIntervalId) {
        clearInterval(refreshIntervalId);
    }

    refreshIntervalId = setInterval(async () => {
        console.log('Auto-refreshing Hugging Face data...');
        await fetchHFData();
    }, REFRESH_INTERVAL_MS);

    console.log(`Auto-refresh enabled: every ${REFRESH_INTERVAL_MS / 60000} minutes`);
}

/**
 * Stop auto-refresh interval
 */
function stopAutoRefresh() {
    if (refreshIntervalId) {
        clearInterval(refreshIntervalId);
        refreshIntervalId = null;
        console.log('Auto-refresh disabled');
    }
}

/**
 * Get the cached stories
 */
function getHFStories() {
    return hfStoriesCache;
}

/**
 * Get cache status
 */
function getHFCacheStatus() {
    return {
        isLoaded,
        storyCount: Object.keys(hfStoriesCache).length,
        lastFetchTime,
        autoRefreshEnabled: refreshIntervalId !== null,
        refreshIntervalMinutes: REFRESH_INTERVAL_MS / 60000
    };
}

/**
 * Get the HF Asset Base URL
 */
function getHFAssetBase() {
    return HF_ASSET_BASE;
}

module.exports = {
    fetchHFData,
    forceRefreshHFData,
    startAutoRefresh,
    stopAutoRefresh,
    getHFStories,
    getHFCacheStatus,
    getHFAssetBase
};