/**
 * 视频缓存管理工具
 * 用于管理本地视频缓存，清理过期或超出限制的缓存
 */

const MAX_CACHE_SIZE = 50; // 最多缓存50个视频
const MAX_CACHE_AGE = 30 * 24 * 60 * 60 * 1000; // 30天过期

/**
 * 清理过期的视频缓存
 */
export function cleanExpiredCache() {
	try {
		const cacheInfo = uni.getStorageSync('video_cache_info') || {};
		const now = Date.now();
		let cleaned = 0;
		
		Object.keys(cacheInfo).forEach(key => {
			const cache = cacheInfo[key];
			// 检查是否过期
			if (now - cache.time > MAX_CACHE_AGE) {
				console.log('[CacheManager] 清理过期缓存:', cache.url);
				// 删除文件
				uni.removeSavedFile({
					filePath: cache.path,
					success: () => {
						console.log('[CacheManager] 文件已删除:', cache.path);
					}
				});
				// 删除映射
				uni.removeStorageSync(key);
				delete cacheInfo[key];
				cleaned++;
			}
		});
		
		// 更新缓存信息
		if (cleaned > 0) {
			uni.setStorageSync('video_cache_info', cacheInfo);
			console.log(`[CacheManager] 已清理 ${cleaned} 个过期缓存`);
		}
		
		return cleaned;
	} catch (e) {
		console.error('[CacheManager] 清理缓存失败:', e);
		return 0;
	}
}

/**
 * 清理最旧的缓存（当缓存数量超过限制时）
 */
export function cleanOldestCache() {
	try {
		const cacheInfo = uni.getStorageSync('video_cache_info') || {};
		const cacheList = Object.keys(cacheInfo).map(key => ({
			key,
			...cacheInfo[key]
		}));
		
		// 如果缓存数量未超过限制，不需要清理
		if (cacheList.length <= MAX_CACHE_SIZE) {
			return 0;
		}
		
		// 按时间排序，删除最旧的
		cacheList.sort((a, b) => a.time - b.time);
		const toDelete = cacheList.length - MAX_CACHE_SIZE;
		let cleaned = 0;
		
		for (let i = 0; i < toDelete; i++) {
			const cache = cacheList[i];
			console.log('[CacheManager] 清理旧缓存:', cache.url);
			// 删除文件
			uni.removeSavedFile({
				filePath: cache.path,
				success: () => {
					console.log('[CacheManager] 文件已删除:', cache.path);
				}
			});
			// 删除映射
			uni.removeStorageSync(cache.key);
			delete cacheInfo[cache.key];
			cleaned++;
		}
		
		// 更新缓存信息
		if (cleaned > 0) {
			uni.setStorageSync('video_cache_info', cacheInfo);
			console.log(`[CacheManager] 已清理 ${cleaned} 个旧缓存`);
		}
		
		return cleaned;
	} catch (e) {
		console.error('[CacheManager] 清理缓存失败:', e);
		return 0;
	}
}

/**
 * 获取缓存统计信息
 */
export function getCacheStats() {
	try {
		const cacheInfo = uni.getStorageSync('video_cache_info') || {};
		const cacheList = Object.keys(cacheInfo);
		
		return {
			count: cacheList.length,
			maxCount: MAX_CACHE_SIZE,
			maxAge: MAX_CACHE_AGE
		};
	} catch (e) {
		console.error('[CacheManager] 获取缓存统计失败:', e);
		return {
			count: 0,
			maxCount: MAX_CACHE_SIZE,
			maxAge: MAX_CACHE_AGE
		};
	}
}

/**
 * 清空所有视频缓存
 */
export function clearAllCache() {
	try {
		const cacheInfo = uni.getStorageSync('video_cache_info') || {};
		let cleaned = 0;
		
		Object.keys(cacheInfo).forEach(key => {
			const cache = cacheInfo[key];
			// 删除文件
			uni.removeSavedFile({
				filePath: cache.path,
				success: () => {
					console.log('[CacheManager] 文件已删除:', cache.path);
				}
			});
			// 删除映射
			uni.removeStorageSync(key);
			cleaned++;
		});
		
		// 清空缓存信息
		uni.removeStorageSync('video_cache_info');
		console.log(`[CacheManager] 已清空所有缓存，共 ${cleaned} 个`);
		
		return cleaned;
	} catch (e) {
		console.error('[CacheManager] 清空缓存失败:', e);
		return 0;
	}
}