using Aliyun.OSS;
using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using VOL.Core.Configuration;

namespace VOL.Core.Utilities
{
    /// <summary>
    /// 阿里云Oss
    /// </summary>
    public class ALiYunOss
    {
        /// <summary>
        /// 上传
        /// </summary>
        /// <param name="isIncludeExtension">是否包含文件后缀名</param>
        /// <returns></returns>
        public static string Upload(IFormFile file, string filePath, string fileName, bool isIncludeExtension = false)
        {
            if (file == null || file.Length == 0)
            {
                throw new ArgumentNullException("上传文件为空");
            }
            var url = string.Empty;

            if (!isIncludeExtension)
            {
                // 拼接文件后缀名
                var extension = Path.GetExtension(file.FileName);
                filePath += fileName + extension;
            }
            else
            {
                filePath += fileName;
            }

            var stream = new MemoryStream();
            file.CopyTo(stream);
            stream.Position = 0;

            // 创建OSSClient实例
            var client = new OssClient(
                AppSetting.ALiYunOSS.Endpoint,
                AppSetting.ALiYunOSS.AccessKeyId,
                AppSetting.ALiYunOSS.SecretAccessKey);

            try
            {
                // 上传文件
                var result = client.PutObject(AppSetting.YueDongServerOSS.BucketName, filePath, stream);
                var uri = client.GeneratePresignedUri(AppSetting.YueDongServerOSS.BucketName, filePath);
                url = "https://" + uri.Host + uri.LocalPath;
                if (result.HttpStatusCode != HttpStatusCode.OK)
                    throw new Exception("上传失败");
            }
            catch (Exception ex)
            {
                throw new Exception("上传失败！");
            }
            finally
            {
                stream.Dispose();
            }

            return url;
        }

        /// <summary>
        /// 获取指定前缀目录下的所有文件列表
        /// </summary>
        /// <param name="prefix">目录前缀，例如"student/"</param>
        /// <returns>文件键列表</returns>
        public static Dictionary<string, string> GetFileFromOss(string prefix)
        {
            var client = new OssClient(
                AppSetting.ALiYunOSS.Endpoint,
                AppSetting.ALiYunOSS.AccessKeyId,
                AppSetting.ALiYunOSS.SecretAccessKey);

            var listObjectsRequest = new ListObjectsRequest(AppSetting.YueDongServerOSS.BucketName)
            {
                Prefix = prefix
            };

            var result = client.ListObjects(listObjectsRequest);

            Dictionary<string, string> imageDataDict = new Dictionary<string, string>();
            foreach (var obj in result.ObjectSummaries)
            {
                // Fetch the object data from OSS
                var objectData = client.GetObject(AppSetting.YueDongServerOSS.BucketName, obj.Key);
                using (var memoryStream = new MemoryStream())
                {
                    objectData.Content.CopyTo(memoryStream);
                    byte[] imageBytes = memoryStream.ToArray();
                    string base64Image = Convert.ToBase64String(imageBytes);
                    imageDataDict.Add(obj.Key, base64Image); // Store the file name and base64 data
                }
            }

            return imageDataDict;
        }

        /// <summary>
        /// 根据前缀删除指定路径下的所有文件
        /// </summary>
        /// <param name="prefix">目录前缀，例如"student/"</param>
        public static void DeleteFilesByPrefix(string prefix)
        {
            var client = new OssClient(
                AppSetting.ALiYunOSS.Endpoint,
                AppSetting.ALiYunOSS.AccessKeyId,
                AppSetting.ALiYunOSS.SecretAccessKey);

            // 列出指定前缀的所有文件
            var listObjectsRequest = new ListObjectsRequest(AppSetting.YueDongServerOSS.BucketName)
            {
                Prefix = prefix
            };

            var result = client.ListObjects(listObjectsRequest);

            // 如果没有找到文件，直接返回
            if (result.ObjectSummaries.Count() == 0)
            {
                return;
            }

            // 删除所有文件
            foreach (var obj in result.ObjectSummaries)
            {
                try
                {
                    // 删除文件
                    client.DeleteObject(AppSetting.YueDongServerOSS.BucketName, obj.Key);
                }
                catch (Exception ex)
                {
                    throw new Exception("删除失败！");
                }
            }
        }
    }
}