using System.Net.Http;
using System.Net.Http.Headers;
using System.Text.Json;
using System.Text.Json.Serialization;
using JsonSerializer = System.Text.Json.JsonSerializer;
using System.IO;

namespace OASystem.API.OAMethodLib.DeepSeekAPI
{
    /// <summary>
    /// DeepSeek API 服务实现
    /// </summary>
    public class DeepSeekService : IDeepSeekService
    {
        private readonly HttpClient _httpClient;
        private readonly ILogger<DeepSeekService> _logger;
        private readonly IHostEnvironment _hostEnvironment;

        /// <summary>
        /// 配置文件
        /// </summary>
        private DeepSeek DeepSeek { get; set; }

        /// <summary>
        /// 构造函数
        /// </summary>
        public DeepSeekService(IHostEnvironment hostEnvironment, ILogger<DeepSeekService> logger, HttpClient httpClient)
        {
            _hostEnvironment = hostEnvironment;
            _httpClient = httpClient;
            _logger = logger;
            DeepSeek = AutofacIocManager.Instance.GetService<DeepSeek>();

            // 设置基础地址和认证头
            _httpClient.BaseAddress = new Uri(DeepSeek.BaseAddress ?? "https://api.deepseek.com/v1/");
            _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", DeepSeek.ApiKey);
            _httpClient.DefaultRequestHeaders.Add("Accept", "application/json");
        }


        /// <summary>
        /// 测试API连通性
        /// </summary>
        /// <returns></returns>
        public async Task<bool> TestApiConnectivityAsync()
        {
            try
            {
                var response = await _httpClient.GetAsync("models");
                return response.IsSuccessStatusCode;
            }
            catch
            {
                return false;
            }
        }

        /// <summary>
        /// 检查可用端点
        /// </summary>
        /// <returns></returns>
        public async Task<List<string>> DiscoverAvailableEndpointsAsync()
        {
            var endpoints = new List<string>
        {
            "models",
            "chat/completions",
            "files",
            "uploads",
            "documents",
            "assistants"
        };

            var availableEndpoints = new List<string>();

            foreach (var endpoint in endpoints)
            {
                try
                {
                    var response = await _httpClient.GetAsync(endpoint);
                    if (response.IsSuccessStatusCode)
                    {
                        availableEndpoints.Add(endpoint);
                        Console.WriteLine($"✅ 端点可用: {endpoint}");
                    }
                    else
                    {
                        Console.WriteLine($"❌ 端点不可用: {endpoint} - {response.StatusCode}");
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"⚠️ 端点检查错误: {endpoint} - {ex.Message}");
                }
            }

            return availableEndpoints;
        }

        /// <summary>
        /// 上传文件到DeepSeek API
        /// </summary>
        public async Task<DeepSeekFileUploadResponse> UploadFileAsync(IFormFile file, string purpose = "assistants")
        {
            try
            {
                _logger.LogInformation("开始上传文件: {FileName}, 大小: {Size} bytes", file.FileName, file.Length);

                // 检查文件大小
                if (file.Length > 512 * 1024 * 1024) // 512MB限制
                {
                    throw new Exception($"文件大小超过限制: {file.Length} bytes");
                }

                using var content = new MultipartFormDataContent();
                using var fileStream = file.OpenReadStream();
                var fileContent = new StreamContent(fileStream);
                fileContent.Headers.ContentType = new MediaTypeHeaderValue(GetContentType(file.FileName));

                content.Add(fileContent, "file", file.FileName);
                content.Add(new StringContent(purpose), "purpose");

                var response = await _httpClient.PostAsync("files", content);
                _logger.LogInformation("文件上传路径：{filePath}", response.RequestMessage.RequestUri);
                response.EnsureSuccessStatusCode();

                var responseContent = await response.Content.ReadAsStringAsync();
                var result = JsonSerializer.Deserialize<DeepSeekFileUploadResponse>(responseContent, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });

                _logger.LogInformation("文件上传成功: {FileName}, FileId: {FileId}", file.FileName, result.Id);

                return result;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "文件上传失败: {FileName}", file.FileName);
                throw;
            }
        }

        /// <summary>
        /// 批量上传文件
        /// </summary>
        public async Task<List<FileUploadResult>> UploadFilesAsync(List<IFormFile> files, string purpose = "assistants")
        {
            var results = new List<FileUploadResult>();

            foreach (var file in files)
            {
                var result = new FileUploadResult
                {
                    FileName = file.FileName,
                    FileSize = file.Length
                };

                try
                {
                    var uploadResponse = await UploadFileAsync(file, purpose);
                    result.FileId = uploadResponse.Id;
                    result.Success = true;
                    result.Status = uploadResponse.Status;
                    result.Message = "上传成功";
                }
                catch (Exception ex)
                {
                    result.Success = false;
                    result.Message = $"上传失败: {ex.Message}";
                    result.Status = "error";
                }

                results.Add(result);
            }

            return results;
        }

        /// <summary>
        /// 获取文件列表
        /// </summary>
        public async Task<DeepSeekFileListResponse> ListFilesAsync()
        {
            try
            {
                var response = await _httpClient.GetAsync("files");
                response.EnsureSuccessStatusCode();

                var responseContent = await response.Content.ReadAsStringAsync();
                return JsonSerializer.Deserialize<DeepSeekFileListResponse>(responseContent, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "获取文件列表失败");
                throw;
            }
        }

        /// <summary>
        /// 获取文件信息
        /// </summary>
        public async Task<DeepSeekFileUploadResponse> GetFileInfoAsync(string fileId)
        {
            try
            {
                var response = await _httpClient.GetAsync($"files/{fileId}");
                response.EnsureSuccessStatusCode();

                var responseContent = await response.Content.ReadAsStringAsync();
                return JsonSerializer.Deserialize<DeepSeekFileUploadResponse>(responseContent, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "获取文件信息失败: {FileId}", fileId);
                throw;
            }
        }

        /// <summary>
        /// 删除文件
        /// </summary>
        public async Task<bool> DeleteFileAsync(string fileId)
        {
            try
            {
                var response = await _httpClient.DeleteAsync($"files/{fileId}");
                response.EnsureSuccessStatusCode();

                _logger.LogInformation("文件删除成功: {FileId}", fileId);
                return true;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "文件删除失败: {FileId}", fileId);
                return false;
            }
        }

        /// <summary>
        /// 使用已上传的文件进行聊天
        /// </summary>
        public async Task<ApiResponse> ChatWithFilesAsync(List<string> fileIds, string question, string model = "deepseek-chat", float temperature = 0.7f, int maxTokens = 4000)
        {
            try
            {
                // 等待所有文件处理完成
                var processedFiles = new List<DeepSeekFileUploadResponse>();
                foreach (var fileId in fileIds)
                {
                    var fileInfo = await WaitForFileProcessingAsync(fileId);
                    processedFiles.Add(fileInfo);
                }

                // 构建消息内容
                var messageContent = new List<object>
                {
                    new { type = "text", text = question }
                };

                // 添加文件引用
                foreach (var file in processedFiles)
                {
                    messageContent.Add(new
                    {
                        type = "file",
                        file_id = file.Id
                    });
                }

                var request = new DeepSeekChatWithFilesRequest
                {
                    Model = model,
                    Messages = new List<FileMessage>
                    {
                        new FileMessage
                        {
                            Role = "user",
                            Content = messageContent
                        }
                    },
                    Temperature = temperature,
                    MaxTokens = maxTokens
                };

                var jsonContent = JsonSerializer.Serialize(request, new JsonSerializerOptions
                {
                    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
                });

                var httpContent = new StringContent(jsonContent, Encoding.UTF8, "application/json");
                var response = await _httpClient.PostAsync("chat/completions", httpContent);
                response.EnsureSuccessStatusCode();

                var responseContent = await response.Content.ReadAsStringAsync();
                var chatResponse = JsonSerializer.Deserialize<DeepSeekResponse>(responseContent, new JsonSerializerOptions
                {
                    PropertyNameCaseInsensitive = true
                });

                return new ApiResponse
                {
                    Success = true,
                    Message = "聊天成功",
                    Answer = chatResponse.Choices[0].Message.Content,
                    TokensUsed = chatResponse.Usage.TotalTokens
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "使用文件聊天失败");
                throw;
            }
        }

        /// <summary>
        /// 等待文件处理完成
        /// </summary>
        public async Task<DeepSeekFileUploadResponse> WaitForFileProcessingAsync(string fileId, int timeoutSeconds = 60)
        {
            var startTime = DateTime.UtcNow;
            var timeout = TimeSpan.FromSeconds(timeoutSeconds);

            while (DateTime.UtcNow - startTime < timeout)
            {
                var fileInfo = await GetFileInfoAsync(fileId);

                if (fileInfo.Status == "processed")
                {
                    _logger.LogInformation("文件处理完成: {FileId}", fileId);
                    return fileInfo;
                }
                else if (fileInfo.Status == "error")
                {
                    throw new Exception($"文件处理失败: {fileId}");
                }

                // 等待2秒后重试
                await Task.Delay(2000);
            }

            throw new TimeoutException($"文件处理超时: {fileId}");
        }

        /// <summary>
        /// 根据文件名获取Content-Type
        /// </summary>
        private static string GetContentType(string fileName)
        {
            var extension = Path.GetExtension(fileName).ToLower();
            return extension switch
            {
                ".txt" => "text/plain",
                ".pdf" => "application/pdf",
                ".json" => "application/json",
                ".csv" => "text/csv",
                ".html" => "text/html",
                ".htm" => "text/html",
                ".md" => "text/markdown",
                _ => "application/octet-stream"
            };
        }

        #region 项目相关

        /// <summary>
        /// 读取项目内的指定文件并转换为IFormFile
        /// </summary>
        public async Task<ProjectFileReadResponse> ReadProjectFilesAsync(List<string> relativePaths)
        {
            var response = new ProjectFileReadResponse();
            var projectRoot = GetProjectRootPath();
            if (projectRoot.Contains("OASystem.Api"))
            {
                projectRoot = projectRoot.Replace("OASystem.Api", "");
            }

            _logger.LogInformation("开始读取项目文件，数量: {Count}", relativePaths.Count);

            foreach (var relativePath in relativePaths)
            {
                var fileInfo = new ProjectFileInfo
                {
                    RelativePath = relativePath
                };

                try
                {
                    var fullPath = Path.Combine(projectRoot, relativePath);
                    fileInfo.FullPath = fullPath;

                    if (!System.IO.File.Exists(fullPath))
                    {
                        throw new FileNotFoundException($"文件不存在: {relativePath}");
                    }

                    var fileInfoObj = new FileInfo(fullPath);
                    fileInfo.FileSize = fileInfoObj.Length;
                    fileInfo.LastModified = fileInfoObj.LastWriteTime;

                    // 转换为IFormFile
                    fileInfo.FormFile = await ConvertToFormFileAsync(fullPath);
                    fileInfo.Success = true;

                    _logger.LogInformation("文件读取成功: {FileName}, 大小: {Size} bytes", relativePath, fileInfo.FileSize);
                }
                catch (Exception ex)
                {
                    fileInfo.Success = false;
                    fileInfo.ErrorMessage = ex.Message;
                    _logger.LogError(ex, "文件读取失败: {FileName}", relativePath);
                }

                response.FileInfos.Add(fileInfo);
            }

            response.Success = response.SuccessCount > 0;
            response.Message = $"成功读取 {response.SuccessCount} 个文件，失败 {response.FailureCount} 个";

            return response;
        }

        /// <summary>
        /// 读取项目内指定目录的文件
        /// </summary>
        public async Task<ProjectFileReadResponse> ReadProjectDirectoryAsync(string directoryPath, string searchPattern = "*.cs", bool recursive = false)
        {
            var response = new ProjectFileReadResponse();
            var projectRoot = GetProjectRootPath();
            var fullDirectoryPath = Path.Combine(projectRoot, directoryPath);

            _logger.LogInformation("开始读取目录文件: {Directory}, 模式: {Pattern}", directoryPath, searchPattern);

            if (!Directory.Exists(fullDirectoryPath))
            {
                response.Success = false;
                response.Message = $"目录不存在: {directoryPath}";
                return response;
            }

            var searchOption = recursive ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly;
            var files = Directory.GetFiles(fullDirectoryPath, searchPattern, searchOption);

            _logger.LogInformation("找到 {FileCount} 个文件", files.Length);

            foreach (var filePath in files)
            {
                var relativePath = Path.GetRelativePath(projectRoot, filePath);
                var fileInfo = new ProjectFileInfo
                {
                    RelativePath = relativePath,
                    FullPath = filePath
                };

                try
                {
                    var fileInfoObj = new FileInfo(filePath);
                    fileInfo.FileSize = fileInfoObj.Length;
                    fileInfo.LastModified = fileInfoObj.LastWriteTime;

                    // 转换为IFormFile
                    fileInfo.FormFile = await ConvertToFormFileAsync(filePath);
                    fileInfo.Success = true;

                    _logger.LogDebug("文件读取成功: {FileName}", relativePath);
                }
                catch (Exception ex)
                {
                    fileInfo.Success = false;
                    fileInfo.ErrorMessage = ex.Message;
                    _logger.LogError(ex, "文件读取失败: {FileName}", relativePath);
                }

                response.FileInfos.Add(fileInfo);
            }

            response.Success = response.SuccessCount > 0;
            response.Message = $"成功读取 {response.SuccessCount} 个文件，失败 {response.FailureCount} 个";

            return response;
        }

        /// <summary>
        /// 获取项目根目录路径
        /// </summary>
        public string GetProjectRootPath()
        {
            // 在开发环境中使用ContentRootPath，在生产环境中可能需要调整
            return _hostEnvironment.ContentRootPath;
        }

        /// <summary>
        /// 检查文件是否存在
        /// </summary>
        public bool FileExists(string relativePath)
        {
            var fullPath = Path.Combine(GetProjectRootPath(), relativePath);
            return System.IO.File.Exists(fullPath);
        }

        /// <summary>
        /// 将物理文件转换为IFormFile
        /// </summary>
        public async Task<IFormFile> ConvertToFormFileAsync(string filePath)
        {
            var fileInfo = new FileInfo(filePath);
            var fileName = Path.GetFileName(filePath);

            // 读取文件内容
            byte[] fileBytes;
            using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {
                fileBytes = new byte[fileStream.Length];
                await fileStream.ReadAsync(fileBytes, 0, (int)fileStream.Length);
            }

            // 创建IFormFile
            return new FormFile(
                new MemoryStream(fileBytes),
                0,
                fileBytes.Length,
                "file",
                fileName)
            {
                Headers = new HeaderDictionary(),
                ContentType = GetFileContentType(fileName)
            };
        }

        /// <summary>
        /// 根据文件名获取Content-Type
        /// </summary>
        private string GetFileContentType(string fileName)
        {
            var extension = Path.GetExtension(fileName).ToLower();
            return extension switch
            {
                ".cs" => "text/plain",
                ".txt" => "text/plain",
                ".json" => "application/json",
                ".xml" => "application/xml",
                ".html" => "text/html",
                ".htm" => "text/html",
                ".css" => "text/css",
                ".js" => "application/javascript",
                ".ts" => "application/typescript",
                ".py" => "text/x-python",
                ".java" => "text/x-java",
                ".cpp" => "text/x-c++",
                ".c" => "text/x-c",
                ".h" => "text/x-c",
                ".md" => "text/markdown",
                _ => "application/octet-stream"
            };
        }


        /// <summary>
        /// 读取特定的签证申请表单文件
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public async Task<ProjectFileReadResponse> ReadVisaFormFileAsync(string fileName)
        {
            var specificPath = $@"OASystem\OASystem.Domain\ViewModels\VisaFormDetails\{fileName}";
            return await ReadProjectFilesAsync(new List<string> { specificPath });
        }

        /// <summary>
        /// 读取OASystem项目中的所有CS文件
        /// </summary>
        public async Task<ProjectFileReadResponse> ReadOASystemFilesAsync(string searchPattern = "*.cs", bool recursive = true)
        {
            return await ReadProjectDirectoryAsync(@"OASystem", searchPattern, recursive);
        }

        /// <summary>
        /// 读取指定域模型中的CS文件
        /// </summary>
        public async Task<ProjectFileReadResponse> ReadDomainViewModelsAsync(string searchPattern = "*.cs", bool recursive = true)
        {
            return await ReadProjectDirectoryAsync(@"OASystem\OASystem.Domain\ViewModels", searchPattern, recursive);
        }

        /// <summary>
        /// 读取签证表单相关的所有CS文件
        /// </summary>
        public async Task<ProjectFileReadResponse> ReadVisaFormFilesAsync(string searchPattern = "*.cs", bool recursive = true)
        {
            return await ReadProjectDirectoryAsync(@"OASystem\OASystem.Domain\ViewModels\VisaFormDetails", searchPattern, recursive);
        }

        #endregion
    }

    #region 私有实体类

    /// <summary>
    /// DeepSeek 聊天响应（用于反序列化）
    /// </summary>
    internal class DeepSeekResponse
    {
        [JsonPropertyName("choices")]
        public List<Choice> Choices { get; set; }

        [JsonPropertyName("usage")]
        public Usage Usage { get; set; }
    }

    internal class Choice
    {
        [JsonPropertyName("message")]
        public Message Message { get; set; }
    }

    internal class Message
    {
        [JsonPropertyName("content")]
        public string Content { get; set; }
    }

    internal class Usage
    {
        [JsonPropertyName("total_tokens")]
        public int TotalTokens { get; set; }
    }

    #endregion

}