using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AIK.Models.FileModels
{
    public class FileCacheStats
    {
        public int TotalCachedFiles { get; set; }
        public long TotalCacheSizeBytes { get; set; }
        public string TotalCacheSizeFormatted => FormatFileSize(TotalCacheSizeBytes);
        public int ExpiredFilesCount { get; set; }
        public string CacheDirectory { get; set; }
        public DateTime LastCleanupTime { get; set; }
        public long AvailableDiskSpaceBytes { get; set; }
        public string AvailableDiskSpaceFormatted => FormatFileSize(AvailableDiskSpaceBytes);
        public Dictionary<string, int> FileTypeCounts { get; set; } = new Dictionary<string, int>();

        private static string FormatFileSize(long bytes)
        {
            string[] sizes = { "B", "KB", "MB", "GB" };
            int order = 0;
            double len = bytes;
            while (len >= 1024 && order < sizes.Length - 1)
            {
                order++;
                len /= 1024;
            }
            return $"{len:0.##} {sizes[order]}";
        }
    }
    public class CachedFileInfo
    {
        public string FileUrl { get; set; }
        public string CacheKey { get; set; }
        public string LocalFilePath { get; set; }
        public string FileName { get; set; }
        public string FileExtension { get; set; }
        public string MimeType { get; set; }
        public long FileSizeBytes { get; set; }
        public string FileSizeFormatted => FormatFileSize(FileSizeBytes);
        public DateTime CreatedTime { get; set; }
        public DateTime LastAccessTime { get; set; }
        public int AccessCount { get; set; }
        public DateTime ExpiryTime { get; set; }
        public bool IsExpired => ExpiryTime < DateTime.Now;
        public string FileHash { get; set; }
        public TimeSpan DownloadTime { get; set; }
        public bool IsValid { get; set; } = true;

        private static string FormatFileSize(long bytes)
        {
            string[] sizes = { "B", "KB", "MB", "GB" };
            int order = 0;
            double len = bytes;
            while (len >= 1024 && order < sizes.Length - 1)
            {
                order++;
                len /= 1024;
            }
            return $"{len:0.##} {sizes[order]}";
        }
    }
    public class FileCacheConfig
    {
        public TimeSpan DefaultCacheExpiry { get; set; } = TimeSpan.FromDays(30);
        public long MaxCacheSizeBytes { get; set; } = 2L * 1024 * 1024 * 1024; // 2GB
        public long MinFreeDiskSpaceBytes { get; set; } = 500L * 1024 * 1024; // 500MB
        public int MaxRetryCount { get; set; } = 3;
        public TimeSpan RetryDelay { get; set; } = TimeSpan.FromSeconds(2);
        public TimeSpan HttpClientTimeout { get; set; } = TimeSpan.FromSeconds(60);
        public string CacheDirectory { get; set; }
        public bool EnableAutoCleanup { get; set; } = true;
        public TimeSpan CleanupInterval { get; set; } = TimeSpan.FromHours(1);
    }
}