feat: 流式处理统一返回用户/系统内容并完善消息存储

引入 StreamProcessResult 统一封装流式处理结果，补充各 API 类型下用户输入与系统输出内容的提取与累计，用于会话消息持久化与用量统计；同时增强 Gemini 请求与响应内容解析能力，确保流式场景下消息与 token 使用数据完整一致。

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs

@@ -6,6 +6,83 @@ namespace Yi.Framework.AiHub.Domain.Shared.Dtos.Gemini;
 
 public static class GeminiGenerateContentAcquirer
 {
+    /// <summary>
+    /// 从请求体中提取用户最后一条消息内容
+    /// 路径: contents[last].parts[last].text
+    /// </summary>
+    public static string GetLastUserContent(JsonElement request)
+    {
+        var contents = request.GetPath("contents");
+        if (!contents.HasValue || contents.Value.ValueKind != JsonValueKind.Array)
+        {
+            return string.Empty;
+        }
+
+        var contentsArray = contents.Value.EnumerateArray().ToList();
+        if (contentsArray.Count == 0)
+        {
+            return string.Empty;
+        }
+
+        var lastContent = contentsArray[^1];
+        var parts = lastContent.GetPath("parts");
+        if (!parts.HasValue || parts.Value.ValueKind != JsonValueKind.Array)
+        {
+            return string.Empty;
+        }
+
+        var partsArray = parts.Value.EnumerateArray().ToList();
+        if (partsArray.Count == 0)
+        {
+            return string.Empty;
+        }
+
+        // 获取最后一个 part 的 text
+        var lastPart = partsArray[^1];
+        return lastPart.GetPath("text").GetString() ?? string.Empty;
+    }
+
+    /// <summary>
+    /// 从响应中提取文本内容（非 thought 类型）
+    /// 路径: candidates[0].content.parts[].text (where thought != true)
+    /// </summary>
+    public static string GetTextContent(JsonElement response)
+    {
+        var candidates = response.GetPath("candidates");
+        if (!candidates.HasValue || candidates.Value.ValueKind != JsonValueKind.Array)
+        {
+            return string.Empty;
+        }
+
+        var candidatesArray = candidates.Value.EnumerateArray().ToList();
+        if (candidatesArray.Count == 0)
+        {
+            return string.Empty;
+        }
+
+        var parts = candidatesArray[0].GetPath("content", "parts");
+        if (!parts.HasValue || parts.Value.ValueKind != JsonValueKind.Array)
+        {
+            return string.Empty;
+        }
+
+        // 遍历所有 parts，只取非 thought 的 text
+        foreach (var part in parts.Value.EnumerateArray())
+        {
+            var isThought = part.GetPath("thought").GetBool();
+            if (!isThought)
+            {
+                var text = part.GetPath("text").GetString();
+                if (!string.IsNullOrEmpty(text))
+                {
+                    return text;
+                }
+            }
+        }
+
+        return string.Empty;
+    }
+
     public static ThorUsageResponse? GetUsage(JsonElement response)
     {
         var usage = response.GetPath("usageMetadata");

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/AiGateWayManager.cs

@@ -1177,27 +1177,27 @@ public class AiGateWayManager : DomainService
                 }
             }
         }, cancellationToken);
-
+        
-        ThorUsageResponse? tokenUsage = null;
+        StreamProcessResult? processResult = null;
 
         switch (apiType)
         {
             case ModelApiTypeEnum.Completions:
-                tokenUsage = await ProcessCompletionsStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
+                processResult = await ProcessCompletionsStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
                 break;
             case ModelApiTypeEnum.Messages:
-                tokenUsage = await ProcessAnthropicStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
+                processResult = await ProcessAnthropicStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
                 break;
             case ModelApiTypeEnum.Responses:
-                tokenUsage = await ProcessOpenAiResponsesStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
+                processResult = await ProcessOpenAiResponsesStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
                 break;
             case ModelApiTypeEnum.GenerateContent:
-                tokenUsage = await ProcessGeminiStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
+                processResult = await ProcessGeminiStreamAsync(messageQueue, requestBody, modelDescribe, cancellationToken);
                 break;
             default:
                 throw new UserFriendlyException($"不支持的API类型: {apiType}");
         }
-
+        
         // 标记完成并等待消费任务结束
         isComplete = true;
         await outputTask;
@@ -1206,25 +1206,25 @@ public class AiGateWayManager : DomainService
         await _aiMessageManager.CreateUserMessageAsync(userId, sessionId,
             new MessageInputDto
             {
-                Content = "不予存储",
+                Content = sessionId is null ? "不予存储" : processResult?.UserContent ?? string.Empty,
                 ModelId = sourceModelId,
-                TokenUsage = tokenUsage,
+                TokenUsage = processResult?.TokenUsage,
             }, tokenId);
 
         await _aiMessageManager.CreateSystemMessageAsync(userId, sessionId,
             new MessageInputDto
             {
-                Content = "不予存储",
+                Content = sessionId is null ? "不予存储" : processResult?.SystemContent ?? string.Empty,
                 ModelId = sourceModelId,
-                TokenUsage = tokenUsage
+                TokenUsage = processResult?.TokenUsage
             }, tokenId);
 
-        await _usageStatisticsManager.SetUsageAsync(userId, sourceModelId, tokenUsage, tokenId);
+        await _usageStatisticsManager.SetUsageAsync(userId, sourceModelId, processResult?.TokenUsage, tokenId);
 
         // 扣减尊享token包用量
-        if (userId.HasValue && tokenUsage is not null && modelDescribe.IsPremium)
+        if (userId.HasValue && processResult?.TokenUsage is not null && modelDescribe.IsPremium)
         {
-            var totalTokens = tokenUsage.TotalTokens ?? 0;
+            var totalTokens = processResult?.TokenUsage.TotalTokens ?? 0;
             if (totalTokens > 0)
             {
                 await PremiumPackageManager.TryConsumeTokensAsync(userId.Value, totalTokens);
@@ -1234,10 +1234,20 @@ public class AiGateWayManager : DomainService
 
     #region 统一流式处理 - 各API类型的具体实现
 
+    /// <summary>
+    /// 流式处理结果，包含用户输入、系统输出和 token 使用情况
+    /// </summary>
+    private class StreamProcessResult
+    {
+        public string UserContent { get; set; } = string.Empty;
+        public string SystemContent { get; set; } = string.Empty;
+        public ThorUsageResponse TokenUsage { get; set; } = new();
+    }
+
     /// <summary>
     /// 处理 OpenAI Completions 格式流式响应
     /// </summary>
-    private async Task<ThorUsageResponse> ProcessCompletionsStreamAsync(
+    private async Task<StreamProcessResult> ProcessCompletionsStreamAsync(
         ConcurrentQueue<string> messageQueue,
         JsonElement requestBody,
         AiModelDescribe modelDescribe,
@@ -1246,6 +1256,9 @@ public class AiGateWayManager : DomainService
         var request = requestBody.Deserialize<ThorChatCompletionsRequest>(ThorJsonSerializer.DefaultOptions)!;
         _specialCompatible.Compatible(request);
 
+        // 提取用户最后一条消息
+        var userContent = request.Messages?.LastOrDefault()?.MessagesStore ?? string.Empty;
+
         // 处理 yi- 前缀
         if (!string.IsNullOrEmpty(request.Model) &&
             request.Model.StartsWith("yi-", StringComparison.OrdinalIgnoreCase))
@@ -1256,6 +1269,7 @@ public class AiGateWayManager : DomainService
         var chatService = LazyServiceProvider.GetRequiredKeyedService<IChatCompletionService>(modelDescribe.HandlerName);
         var completeChatResponse = chatService.CompleteChatStreamAsync(modelDescribe, request, cancellationToken);
         var tokenUsage = new ThorUsageResponse();
+        var systemContentBuilder = new StringBuilder();
 
         try
         {
@@ -1267,6 +1281,13 @@ public class AiGateWayManager : DomainService
                     tokenUsage = data.Usage;
                 }
 
+                // 累加系统输出内容 (choices[].delta.content)
+                var deltaContent = data.Choices?.FirstOrDefault()?.Delta?.Content;
+                if (!string.IsNullOrEmpty(deltaContent))
+                {
+                    systemContentBuilder.Append(deltaContent);
+                }
+
                 var message = JsonSerializer.Serialize(data, ThorJsonSerializer.DefaultOptions);
                 messageQueue.Enqueue($"data: {message}\n\n");
             }
@@ -1275,6 +1296,7 @@ public class AiGateWayManager : DomainService
         {
             _logger.LogError(e, "Ai对话异常");
             var errorContent = $"对话Ai异常，异常信息：\n当前Ai模型：{request.Model}\n异常信息：{e.Message}\n异常堆栈：{e}";
+            systemContentBuilder.Append(errorContent);
             var model = new ThorChatCompletionsResponse()
             {
                 Choices = new List<ThorChatChoiceResponse>()
@@ -1296,13 +1318,18 @@ public class AiGateWayManager : DomainService
         }
 
         messageQueue.Enqueue("data: [DONE]\n\n");
-        return tokenUsage;
+        return new StreamProcessResult
+        {
+            UserContent = userContent,
+            SystemContent = systemContentBuilder.ToString(),
+            TokenUsage = tokenUsage
+        };
     }
 
     /// <summary>
     /// 处理 Anthropic Messages 格式流式响应
     /// </summary>
-    private async Task<ThorUsageResponse> ProcessAnthropicStreamAsync(
+    private async Task<StreamProcessResult> ProcessAnthropicStreamAsync(
         ConcurrentQueue<string> messageQueue,
         JsonElement requestBody,
         AiModelDescribe modelDescribe,
@@ -1311,6 +1338,16 @@ public class AiGateWayManager : DomainService
         var request = requestBody.Deserialize<AnthropicInput>(ThorJsonSerializer.DefaultOptions)!;
         _specialCompatible.AnthropicCompatible(request);
 
+        // 提取用户最后一条消息
+        var lastMessage = request.Messages?.LastOrDefault();
+        var userContent = lastMessage?.Content ?? string.Empty;
+        if (string.IsNullOrEmpty(userContent) && lastMessage?.Contents != null && lastMessage.Contents.Any())
+        {
+            // 如果是 Contents 数组，提取第一个 text 类型的内容
+            var textContent = lastMessage.Contents.FirstOrDefault(c => c.Type == "text");
+            userContent = textContent?.Text ?? System.Text.Json.JsonSerializer.Serialize(lastMessage.Contents);
+        }
+
         // 处理 yi- 前缀
         if (!string.IsNullOrEmpty(request.Model) &&
             request.Model.StartsWith("yi-", StringComparison.OrdinalIgnoreCase))
@@ -1321,6 +1358,7 @@ public class AiGateWayManager : DomainService
         var chatService = LazyServiceProvider.GetRequiredKeyedService<IAnthropicChatCompletionService>(modelDescribe.HandlerName);
         var completeChatResponse = chatService.StreamChatCompletionsAsync(modelDescribe, request, cancellationToken);
         var tokenUsage = new ThorUsageResponse();
+        var systemContentBuilder = new StringBuilder();
 
         try
         {
@@ -1364,6 +1402,13 @@ public class AiGateWayManager : DomainService
                     }
                 }
 
+                // 累加系统输出内容 (delta.text)
+                var deltaText = responseResult.Item2?.Delta?.Text;
+                if (!string.IsNullOrEmpty(deltaText))
+                {
+                    systemContentBuilder.Append(deltaText);
+                }
+
                 // 序列化为SSE格式字符串
                 var data = JsonSerializer.Serialize(responseResult.Item2, ThorJsonSerializer.DefaultOptions);
                 messageQueue.Enqueue($"{responseResult.Item1.Trim()}\ndata: {data}\n\n");
@@ -1373,19 +1418,25 @@ public class AiGateWayManager : DomainService
         {
             _logger.LogError(e, "Ai对话异常");
             var errorContent = $"对话Ai异常，异常信息：\n当前Ai模型：{request.Model}\n异常信息：{e.Message}\n异常堆栈：{e}";
+            systemContentBuilder.Append(errorContent);
             throw new UserFriendlyException(errorContent);
         }
 
         tokenUsage.TotalTokens = (tokenUsage.InputTokens ?? 0) + (tokenUsage.OutputTokens ?? 0);
         tokenUsage.SetSupplementalMultiplier(modelDescribe.Multiplier);
 
-        return tokenUsage;
+        return new StreamProcessResult
+        {
+            UserContent = userContent,
+            SystemContent = systemContentBuilder.ToString(),
+            TokenUsage = tokenUsage
+        };
     }
 
     /// <summary>
     /// 处理 OpenAI Responses 格式流式响应
     /// </summary>
-    private async Task<ThorUsageResponse> ProcessOpenAiResponsesStreamAsync(
+    private async Task<StreamProcessResult> ProcessOpenAiResponsesStreamAsync(
         ConcurrentQueue<string> messageQueue,
         JsonElement requestBody,
         AiModelDescribe modelDescribe,
@@ -1393,6 +1444,27 @@ public class AiGateWayManager : DomainService
     {
         var request = requestBody.Deserialize<OpenAiResponsesInput>(ThorJsonSerializer.DefaultOptions)!;
 
+        // 提取用户输入内容 (input 字段可能是字符串或数组)
+        var userContent = string.Empty;
+        if (request.Input.ValueKind == JsonValueKind.String)
+        {
+            userContent = request.Input.GetString() ?? string.Empty;
+        }
+        else if (request.Input.ValueKind == JsonValueKind.Array)
+        {
+            // 获取最后一个 user 角色的消息
+            var inputArray = request.Input.EnumerateArray().ToList();
+            var lastUserMessage = inputArray.LastOrDefault(x =>
+                x.TryGetProperty("role", out var role) && role.GetString() == "user");
+            if (lastUserMessage.ValueKind != JsonValueKind.Undefined)
+            {
+                if (lastUserMessage.TryGetProperty("content", out var content))
+                {
+                    userContent = content.GetString() ?? string.Empty;
+                }
+            }
+        }
+
         // 处理 yi- 前缀
         if (!string.IsNullOrEmpty(request.Model) &&
             request.Model.StartsWith("yi-", StringComparison.OrdinalIgnoreCase))
@@ -1403,11 +1475,22 @@ public class AiGateWayManager : DomainService
         var chatService = LazyServiceProvider.GetRequiredKeyedService<IOpenAiResponseService>(modelDescribe.HandlerName);
         var completeChatResponse = chatService.ResponsesStreamAsync(modelDescribe, request, cancellationToken);
         ThorUsageResponse? tokenUsage = null;
+        var systemContentBuilder = new StringBuilder();
 
         try
         {
             await foreach (var responseResult in completeChatResponse)
             {
+                // 提取输出文本内容 (response.output_text.delta 事件)
+                if (responseResult.Item1.Contains("response.output_text.delta"))
+                {
+                    var delta = responseResult.Item2?.GetPath("delta").GetString();
+                    if (!string.IsNullOrEmpty(delta))
+                    {
+                        systemContentBuilder.Append(delta);
+                    }
+                }
+
                 if (responseResult.Item1.Contains("response.completed"))
                 {
                     var obj = responseResult.Item2!.Value;
@@ -1434,29 +1517,46 @@ public class AiGateWayManager : DomainService
         {
             _logger.LogError(e, "Ai响应异常");
             var errorContent = $"响应Ai异常，异常信息：\n当前Ai模型：{request.Model}\n异常信息：{e.Message}\n异常堆栈：{e}";
+            systemContentBuilder.Append(errorContent);
             throw new UserFriendlyException(errorContent);
         }
 
-        return tokenUsage ?? new ThorUsageResponse();
+        return new StreamProcessResult
+        {
+            UserContent = userContent,
+            SystemContent = systemContentBuilder.ToString(),
+            TokenUsage = tokenUsage ?? new ThorUsageResponse()
+        };
     }
 
     /// <summary>
     /// 处理 Gemini GenerateContent 格式流式响应
     /// </summary>
-    private async Task<ThorUsageResponse> ProcessGeminiStreamAsync(
+    private async Task<StreamProcessResult> ProcessGeminiStreamAsync(
         ConcurrentQueue<string> messageQueue,
         JsonElement requestBody,
         AiModelDescribe modelDescribe,
         CancellationToken cancellationToken)
     {
+        // 提取用户最后一条消息 (contents[last].parts[last].text)
+        var userContent = GeminiGenerateContentAcquirer.GetLastUserContent(requestBody);
+
         var chatService = LazyServiceProvider.GetRequiredKeyedService<IGeminiGenerateContentService>(modelDescribe.HandlerName);
         var completeChatResponse = chatService.GenerateContentStreamAsync(modelDescribe, requestBody, cancellationToken);
         ThorUsageResponse? tokenUsage = null;
+        var systemContentBuilder = new StringBuilder();
 
         try
         {
             await foreach (var responseResult in completeChatResponse)
             {
+                // 累加系统输出内容 (candidates[0].content.parts[].text，排除 thought)
+                var textContent = GeminiGenerateContentAcquirer.GetTextContent(responseResult!.Value);
+                if (!string.IsNullOrEmpty(textContent))
+                {
+                    systemContentBuilder.Append(textContent);
+                }
+
                 if (responseResult!.Value.GetPath("candidates", 0, "finishReason").GetString() == "STOP")
                 {
                     tokenUsage = GeminiGenerateContentAcquirer.GetUsage(responseResult!.Value);
@@ -1483,10 +1583,16 @@ public class AiGateWayManager : DomainService
         {
             _logger.LogError(e, "Ai生成异常");
             var errorContent = $"生成Ai异常，异常信息：\n当前Ai模型：{modelDescribe.ModelId}\n异常信息：{e.Message}\n异常堆栈：{e}";
+            systemContentBuilder.Append(errorContent);
             throw new UserFriendlyException(errorContent);
         }
 
-        return tokenUsage ?? new ThorUsageResponse();
+        return new StreamProcessResult
+        {
+            UserContent = userContent,
+            SystemContent = systemContentBuilder.ToString(),
+            TokenUsage = tokenUsage ?? new ThorUsageResponse()
+        };
     }
 
     #endregion