using COSXML;
using COSXML.Auth;
using COSXML.Model.Object;
using COSXML.Transfer;
using WorkCameraExport.Models;
using WorkCameraExport.Services.Interfaces;

namespace WorkCameraExport.Services
{
    /// <summary>
    /// COS 服务类 - 处理腾讯云 COS 图片上传
    /// </summary>
    public class CosService : IDisposable
    {
        private CosXml? _cosXml;
        private CosTempCredentials? _credentials;
        private readonly ILogService? _logService;
        private bool _disposed;

        public CosService(ILogService? logService = null)
        {
            _logService = logService;
        }

        /// <summary>
        /// 初始化 COS 客户端
        /// </summary>
        public void Initialize(CosTempCredentials credentials)
        {
            _credentials = credentials;
            _logService?.Info($"[COS] 初始化, Region={credentials.Region}, Bucket={credentials.Bucket}");

            var config = new CosXmlConfig.Builder()
                .IsHttps(true)
                .SetRegion(credentials.Region)
                .SetDebugLog(false)
                .Build();

            var credentialProvider = new DefaultSessionQCloudCredentialProvider(
                credentials.TmpSecretId,
                credentials.TmpSecretKey,
                credentials.ExpiredTime,
                credentials.SessionToken);

            _cosXml = new CosXmlServer(config, credentialProvider);
            _logService?.Info("[COS] 初始化完成");
        }

        /// <summary>
        /// 检查是否已初始化
        /// </summary>
        public bool IsInitialized => _cosXml != null && _credentials != null;

        /// <summary>
        /// 上传图片到 COS
        /// </summary>
        /// <param name="localFilePath">本地文件路径</param>
        /// <param name="cosKey">COS 对象键（路径）</param>
        /// <param name="progress">进度回调</param>
        /// <param name="cancellationToken">取消令牌</param>
        /// <returns>上传结果</returns>
        public async Task<(bool Success, string Message, string? CosUrl)> UploadFileAsync(
            string localFilePath,
            string cosKey,
            Action<long, long>? progress = null,
            CancellationToken cancellationToken = default)
        {
            if (!IsInitialized || _cosXml == null || _credentials == null)
            {
                _logService?.Error("[COS] 上传失败: 服务未初始化");
                return (false, "COS 服务未初始化", null);
            }

            _logService?.Info($"[COS] 开始上传文件: {localFilePath} -> {cosKey}");

            try
            {
                var transferConfig = new TransferConfig();
                var transferManager = new TransferManager(_cosXml, transferConfig);

                var uploadTask = new COSXMLUploadTask(_credentials.Bucket, cosKey);
                uploadTask.SetSrcPath(localFilePath);

                if (progress != null)
                {
                    uploadTask.progressCallback = (completed, total) =>
                    {
                        progress(completed, total);
                    };
                }

                // 使用新的异步 API
                var result = await transferManager.UploadAsync(uploadTask);
                
                if (result.IsSuccessful())
                {
                    var cosUrl = $"https://{_credentials.Bucket}.cos.{_credentials.Region}.myqcloud.com/{cosKey}";
                    _logService?.Info($"[COS] 上传成功: {cosUrl}");
                    return (true, "上传成功", cosUrl);
                }
                else
                {
                    _logService?.Warn($"[COS] 上传失败: result.IsSuccessful()=false");
                    return (false, "上传失败", null);
                }
            }
            catch (OperationCanceledException)
            {
                _logService?.Info("[COS] 上传已取消");
                return (false, "上传已取消", null);
            }
            catch (COSXML.CosException.CosClientException clientEx)
            {
                _logService?.Error($"[COS] 客户端异常: {clientEx.Message}", clientEx);
                return (false, $"客户端异常: {clientEx.Message}", null);
            }
            catch (COSXML.CosException.CosServerException serverEx)
            {
                _logService?.Error($"[COS] 服务端异常: {serverEx.GetInfo()}");
                return (false, $"服务端异常: {serverEx.GetInfo()}", null);
            }
            catch (Exception ex)
            {
                _logService?.Error($"[COS] 上传异常: {ex.Message}", ex);
                return (false, $"上传异常: {ex.Message}", null);
            }
        }

        /// <summary>
        /// 上传字节数组到 COS
        /// </summary>
        public async Task<(bool Success, string Message, string? CosUrl)> UploadBytesAsync(
            byte[] data,
            string cosKey,
            Action<long, long>? progress = null,
            CancellationToken cancellationToken = default)
        {
            if (!IsInitialized || _cosXml == null || _credentials == null)
            {
                return (false, "COS 服务未初始化", null);
            }

            // 创建临时文件
            var tempFile = Path.GetTempFileName();
            try
            {
                await File.WriteAllBytesAsync(tempFile, data, cancellationToken);
                return await UploadFileAsync(tempFile, cosKey, progress, cancellationToken);
            }
            finally
            {
                // 清理临时文件
                try
                {
                    if (File.Exists(tempFile))
                    {
                        File.Delete(tempFile);
                    }
                }
                catch
                {
                    // 忽略清理错误
                }
            }
        }

        /// <summary>
        /// 批量上传图片
        /// </summary>
        /// <param name="uploadTasks">上传任务列表 (本地路径, COS键)</param>
        /// <param name="maxConcurrency">最大并发数</param>
        /// <param name="progress">进度回调 (已完成数, 总数)</param>
        /// <param name="cancellationToken">取消令牌</param>
        /// <returns>上传结果列表</returns>
        public async Task<List<(string LocalPath, bool Success, string? CosUrl, string Message)>> 
            BatchUploadAsync(
                List<(string LocalPath, string CosKey)> uploadTasks,
                int maxConcurrency = 5,
                Action<int, int>? progress = null,
                CancellationToken cancellationToken = default)
        {
            var results = new List<(string LocalPath, bool Success, string? CosUrl, string Message)>();
            var semaphore = new SemaphoreSlim(maxConcurrency);
            var completed = 0;
            var total = uploadTasks.Count;

            var tasks = uploadTasks.Select(async task =>
            {
                await semaphore.WaitAsync(cancellationToken);
                try
                {
                    var result = await UploadFileAsync(task.LocalPath, task.CosKey, 
                        cancellationToken: cancellationToken);
                    
                    lock (results)
                    {
                        results.Add((task.LocalPath, result.Success, result.CosUrl, result.Message));
                        completed++;
                        progress?.Invoke(completed, total);
                    }
                }
                finally
                {
                    semaphore.Release();
                }
            });

            await Task.WhenAll(tasks);
            return results;
        }

        /// <summary>
        /// 生成 COS 对象键（路径）
        /// </summary>
        /// <param name="recordTime">记录时间</param>
        /// <param name="category">分类（当日照片/参与人员/工作内容/部门）</param>
        /// <param name="subCategory">子分类</param>
        /// <param name="fileName">文件名</param>
        /// <returns>COS 对象键</returns>
        public static string GenerateCosKey(DateTime recordTime, string category, 
            string subCategory, string fileName)
        {
            var yearMonth = recordTime.ToString("yyyyMM");
            var date = recordTime.ToString("yyyyMMdd");
            
            if (string.IsNullOrEmpty(subCategory))
            {
                return $"workfiles/{yearMonth}/{date}/{category}/{fileName}";
            }
            
            return $"workfiles/{yearMonth}/{date}/{category}/{subCategory}/{fileName}";
        }

        /// <summary>
        /// 生成唯一文件名
        /// </summary>
        public static string GenerateFileName(string extension = ".jpg")
        {
            var timestamp = DateTime.Now.ToString("yyyyMMddHHmmssfff");
            var random = new Random().Next(1000, 9999);
            return $"{timestamp}_{random}{extension}";
        }

        #region IDisposable

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!_disposed)
            {
                if (disposing)
                {
                    _cosXml = null;
                    _credentials = null;
                }
                _disposed = true;
            }
        }

        #endregion
    }
}