SSE Streaming, Tool-Loop Refactor, Hilfsfunktionen extrahiert

Program.cs

@@ -7,6 +7,7 @@ using System.Net.Http.Headers;
 using System.Text;
 using System.Text.Json;
 using System.Text.Json.Serialization;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
@@ -20,11 +21,12 @@ var app = builder.Build();
 app.UseDefaultFiles();
 app.UseStaticFiles();
 
-// Workspace-Root für Dateioperationen
 var dataDir = Path.Combine(AppContext.BaseDirectory, "data");
 var workspaceRoot = Path.Combine(dataDir, "workspace");
 Directory.CreateDirectory(workspaceRoot);
 
+// ── Tool Definitionen ──
+
 var toolDefs = new[]
 {
     new
@@ -88,11 +90,13 @@ var toolDefs = new[]
     }
 };
 
+// ── Hilfsfunktionen ──
+
 string ResolvePath(string relativePath)
 {
     var full = Path.GetFullPath(Path.Combine(workspaceRoot, relativePath ?? ""));
     if (!full.StartsWith(workspaceRoot))
-        throw new System.Exception("Zugriff außerhalb des Workspace nicht erlaubt");
+        throw new Exception("Zugriff außerhalb des Workspace nicht erlaubt");
     return full;
 }
 
@@ -147,15 +151,45 @@ string ExecuteTool(string name, JsonElement input)
     }
 }
 
-app.MapPost("/api/chat", async (HttpRequest req, IHttpClientFactory httpFactory, IConfiguration config) =>
+async Task WriteSseEvent(HttpResponse response, string eventType, object data)
+{
+    var json = JsonSerializer.Serialize(data);
+    await response.WriteAsync($"event: {eventType}\ndata: {json}\n\n");
+    await response.Body.FlushAsync();
+}
+
+HttpClient CreateAnthropicClient(IHttpClientFactory factory, string token)
+{
+    var client = factory.CreateClient();
+    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
+    client.DefaultRequestHeaders.Add("anthropic-version", "2023-06-01");
+    client.DefaultRequestHeaders.Add("anthropic-beta", "claude-code-20250219,oauth-2025-04-20");
+    client.DefaultRequestHeaders.Add("User-Agent", "claude-cli/2.1.2 (external, cli)");
+    client.DefaultRequestHeaders.Add("x-app", "cli");
+    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
+    client.DefaultRequestHeaders.Add("anthropic-dangerous-direct-browser-access", "true");
+    return client;
+}
+
+// ── SSE Streaming Endpoint ──
+
+app.MapPost("/api/chat", async (HttpRequest req, HttpResponse res, IHttpClientFactory httpFactory, IConfiguration config) =>
 {
     var body = await JsonSerializer.DeserializeAsync<ChatRequest>(req.Body);
     if (body == null || body.Messages == null || body.Messages.Count == 0)
-        return Results.BadRequest(new { error = "messages required" });
+    {
+        res.StatusCode = 400;
+        await res.WriteAsJsonAsync(new { error = "messages required" });
+        return;
+    }
 
     var token = config["AnthropicToken"];
     if (string.IsNullOrEmpty(token))
-        return Results.Problem("AnthropicToken not configured");
+    {
+        res.StatusCode = 500;
+        await res.WriteAsJsonAsync(new { error = "AnthropicToken not configured" });
+        return;
+    }
 
     var modelId = body.Model switch
     {
@@ -164,23 +198,22 @@ app.MapPost("/api/chat", async (HttpRequest req, IHttpClientFactory httpFactory,
         _ => "claude-sonnet-4-6"
     };
 
-    // Messages in API-Format konvertieren
+    // SSE Response starten
+    res.Headers["Content-Type"] = "text/event-stream";
+    res.Headers["Cache-Control"] = "no-cache";
+    res.Headers["Connection"] = "keep-alive";
+
     var messages = new List<object>();
     foreach (var msg in body.Messages)
-    {
         messages.Add(new { role = msg.Role, content = msg.Content });
-    }
 
     var systemPrompt = new List<object>
     {
         new { type = "text", text = "You are Claude Code, Anthropic's official CLI for Claude." }
     };
     if (!string.IsNullOrWhiteSpace(body.SystemPrompt))
-    {
         systemPrompt.Add(new { type = "text", text = body.SystemPrompt });
-    }
 
-    var steps = new List<StepInfo>();
     long totalInputTokens = 0;
     long totalOutputTokens = 0;
     int iterations = 0;
@@ -196,138 +229,219 @@ app.MapPost("/api/chat", async (HttpRequest req, IHttpClientFactory httpFactory,
             ["max_tokens"] = 4096,
             ["system"] = systemPrompt,
             ["messages"] = messages,
-            ["tools"] = toolDefs
+            ["tools"] = toolDefs,
+            ["stream"] = true
         };
 
-        var client = httpFactory.CreateClient();
-        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
-        client.DefaultRequestHeaders.Add("anthropic-version", "2023-06-01");
-        client.DefaultRequestHeaders.Add("anthropic-beta", "claude-code-20250219,oauth-2025-04-20");
-        client.DefaultRequestHeaders.Add("User-Agent", "claude-cli/2.1.2 (external, cli)");
-        client.DefaultRequestHeaders.Add("x-app", "cli");
-        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
-        client.DefaultRequestHeaders.Add("anthropic-dangerous-direct-browser-access", "true");
-
+        var client = CreateAnthropicClient(httpFactory, token);
         var json = JsonSerializer.Serialize(payload);
         var httpContent = new StringContent(json, Encoding.UTF8, "application/json");
 
-        var resp = await client.PostAsync("https://api.anthropic.com/v1/messages", httpContent);
-        var respBody = await resp.Content.ReadAsStringAsync();
+        var httpResp = await client.SendAsync(
+            new HttpRequestMessage(HttpMethod.Post, "https://api.anthropic.com/v1/messages") { Content = httpContent },
+            HttpCompletionOption.ResponseHeadersRead
+        );
 
-        if (!resp.IsSuccessStatusCode)
-            return Results.Problem($"Anthropic API error: {(int)resp.StatusCode} - {respBody}");
-
-        var result = JsonSerializer.Deserialize<JsonElement>(respBody);
-
-        // Usage tracken
-        if (result.TryGetProperty("usage", out var usage))
+        if (!httpResp.IsSuccessStatusCode)
         {
-            if (usage.TryGetProperty("input_tokens", out var it)) totalInputTokens += it.GetInt64();
-            if (usage.TryGetProperty("output_tokens", out var ot)) totalOutputTokens += ot.GetInt64();
+            var errBody = await httpResp.Content.ReadAsStringAsync();
+            await WriteSseEvent(res, "error", new { error = $"API {(int)httpResp.StatusCode}: {errBody}" });
+            await WriteSseEvent(res, "done", new { });
+            return;
         }
 
-        var stopReason = result.GetProperty("stop_reason").GetString();
-        var contentBlocks = result.GetProperty("content");
+        // Anthropic SSE Stream parsen
+        var stream = await httpResp.Content.ReadAsStreamAsync();
+        using var reader = new StreamReader(stream);
 
-        // Assistant-Antwort zur History hinzufügen
+        var stopReason = "";
         var assistantContent = new List<object>();
-        var textParts = new List<string>();
+        var currentToolId = "";
+        var currentToolName = "";
+        var currentToolInputJson = new StringBuilder();
+        var currentTextBlock = new StringBuilder();
+        var blockIndex = -1;
 
-        foreach (var block in contentBlocks.EnumerateArray())
+        var blockTypes = new Dictionary<int, string>();
+        var executedTools = new List<(string Id, string Result, bool IsError)>();
+
+        string line;
+        while ((line = await reader.ReadLineAsync()) != null)
         {
-            var blockType = block.GetProperty("type").GetString();
-            if (blockType == "text")
-            {
-                var text = block.GetProperty("text").GetString() ?? "";
-                textParts.Add(text);
-                assistantContent.Add(new { type = "text", text });
-            }
-            else if (blockType == "tool_use")
-            {
-                var toolId = block.GetProperty("id").GetString() ?? "";
-                var toolName = block.GetProperty("name").GetString() ?? "";
-                var toolInput = block.GetProperty("input");
+            if (!line.StartsWith("data: ")) continue;
 
-                assistantContent.Add(new
+            var data = line["data: ".Length..];
+            if (string.IsNullOrWhiteSpace(data)) continue;
+
+            JsonElement evt;
+            try { evt = JsonSerializer.Deserialize<JsonElement>(data); }
+            catch { continue; }
+
+            var evtType = evt.TryGetProperty("type", out var t) ? t.GetString() ?? "" : "";
+
+            switch (evtType)
+            {
+                case "message_start":
                 {
-                    type = "tool_use",
-                    id = toolId,
-                    name = toolName,
-                    input = toolInput
-                });
+                    if (evt.TryGetProperty("message", out var msg) &&
+                        msg.TryGetProperty("usage", out var u))
+                    {
+                        if (u.TryGetProperty("input_tokens", out var it)) totalInputTokens += it.GetInt64();
+                    }
+                    break;
+                }
+
+                case "content_block_start":
+                {
+                    var idx = evt.GetProperty("index").GetInt32();
+                    var cb = evt.GetProperty("content_block");
+                    var cbType = cb.GetProperty("type").GetString() ?? "";
+                    blockTypes[idx] = cbType;
+
+                    if (cbType == "text")
+                    {
+                        blockIndex = idx;
+                        currentTextBlock.Clear();
+                        await WriteSseEvent(res, "text_start", new { index = idx });
+                    }
+                    else if (cbType == "tool_use")
+                    {
+                        // Vorherigen Text-Block abschließen
+                        if (currentTextBlock.Length > 0)
+                        {
+                            assistantContent.Add(new { type = "text", text = currentTextBlock.ToString() });
+                            currentTextBlock.Clear();
+                        }
+
+                        blockIndex = idx;
+                        currentToolId = cb.GetProperty("id").GetString() ?? "";
+                        currentToolName = cb.GetProperty("name").GetString() ?? "";
+                        currentToolInputJson.Clear();
+                        await WriteSseEvent(res, "tool_start", new { name = currentToolName, id = currentToolId });
+                    }
+                    break;
+                }
+
+                case "content_block_delta":
+                {
+                    var idx = evt.GetProperty("index").GetInt32();
+                    var delta = evt.GetProperty("delta");
+                    var deltaType = delta.GetProperty("type").GetString() ?? "";
+
+                    if (deltaType == "text_delta")
+                    {
+                        var text = delta.GetProperty("text").GetString() ?? "";
+                        currentTextBlock.Append(text);
+                        await WriteSseEvent(res, "text_delta", new { text });
+                    }
+                    else if (deltaType == "input_json_delta")
+                    {
+                        var partial = delta.GetProperty("partial_json").GetString() ?? "";
+                        currentToolInputJson.Append(partial);
+                    }
+                    break;
+                }
+
+                case "content_block_stop":
+                {
+                    var idx = evt.GetProperty("index").GetInt32();
+                    if (blockTypes.TryGetValue(idx, out var bt))
+                    {
+                        if (bt == "text")
+                        {
+                            var text = currentTextBlock.ToString();
+                            if (text.Length > 0)
+                            {
+                                assistantContent.Add(new { type = "text", text });
+                                await WriteSseEvent(res, "text_end", new { });
+                            }
+                            currentTextBlock.Clear();
+                        }
+                        else if (bt == "tool_use")
+                        {
+                            JsonElement inputEl;
+                            try { inputEl = JsonSerializer.Deserialize<JsonElement>(currentToolInputJson.ToString()); }
+                            catch { inputEl = JsonSerializer.Deserialize<JsonElement>("{}"); }
+
+                            assistantContent.Add(new
+                            {
+                                type = "tool_use",
+                                id = currentToolId,
+                                name = currentToolName,
+                                input = inputEl
+                            });
+
+                            // Tool sofort ausführen und streamen
+                            string toolResult;
+                            bool isError = false;
+                            try { toolResult = ExecuteTool(currentToolName, inputEl); }
+                            catch (Exception ex) { toolResult = $"Fehler: {ex.Message}"; isError = true; }
+
+                            executedTools.Add((currentToolId, toolResult, isError));
+
+                            await WriteSseEvent(res, "tool_end", new
+                            {
+                                name = currentToolName,
+                                input = currentToolInputJson.ToString(),
+                                result = toolResult.Length > 500 ? toolResult[..500] + "..." : toolResult,
+                                isError
+                            });
+                        }
+                    }
+                    break;
+                }
+
+                case "message_delta":
+                {
+                    if (evt.TryGetProperty("delta", out var d) &&
+                        d.TryGetProperty("stop_reason", out var sr))
+                        stopReason = sr.GetString() ?? "";
+                    if (evt.TryGetProperty("usage", out var u2) &&
+                        u2.TryGetProperty("output_tokens", out var ot))
+                        totalOutputTokens += ot.GetInt64();
+                    break;
+                }
             }
         }
 
-        messages.Add(new { role = "assistant", content = assistantContent });
+        // Restlichen Text abschließen
+        if (currentTextBlock.Length > 0)
+            assistantContent.Add(new { type = "text", text = currentTextBlock.ToString() });
 
-        // Zwischen-Text als Step erfassen
-        if (textParts.Count > 0)
-        {
-            steps.Add(new StepInfo
-            {
-                Type = "text",
-                Text = string.Join("\n", textParts)
-            });
-        }
+        // Assistant-Antwort zur History
+        messages.Add(new { role = "assistant", content = assistantContent });
 
         // Kein Tool Use? Fertig!
         if (stopReason != "tool_use")
         {
-            return Results.Ok(new
+            await WriteSseEvent(res, "done", new
             {
-                text = string.Join("\n", textParts),
                 model = modelId,
                 inputTokens = totalInputTokens,
                 outputTokens = totalOutputTokens,
-                iterations,
-                steps
+                iterations
             });
+            return;
         }
 
-        // Tool Calls ausführen
+        // Tool Results zusammenbauen (wurden beim Streaming bereits ausgeführt)
         var toolResults = new List<object>();
-        foreach (var block in contentBlocks.EnumerateArray())
+        foreach (var tr in executedTools)
         {
-            if (block.GetProperty("type").GetString() != "tool_use") continue;
-
-            var toolId = block.GetProperty("id").GetString() ?? "";
-            var toolName = block.GetProperty("name").GetString() ?? "";
-            var toolInput = block.GetProperty("input");
-
-            string toolResult;
-            bool isError = false;
-            try
-            {
-                toolResult = ExecuteTool(toolName, toolInput);
-            }
-            catch (System.Exception ex)
-            {
-                toolResult = $"Fehler: {ex.Message}";
-                isError = true;
-            }
-
-            steps.Add(new StepInfo
-            {
-                Type = "tool",
-                ToolName = toolName,
-                ToolInput = toolInput.ToString(),
-                ToolResult = toolResult.Length > 500 ? toolResult[..500] + "..." : toolResult,
-                IsError = isError
-            });
-
             toolResults.Add(new
             {
                 type = "tool_result",
-                tool_use_id = toolId,
-                content = toolResult,
-                is_error = isError
+                tool_use_id = tr.Id,
+                content = tr.Result,
+                is_error = tr.IsError
             });
         }
 
         messages.Add(new { role = "user", content = toolResults });
     }
 
-    return Results.Problem("Max iterations erreicht");
+    await WriteSseEvent(res, "error", new { error = "Max iterations erreicht" });
+    await WriteSseEvent(res, "done", new { });
 });
 
 app.Run("http://0.0.0.0:19000");
@@ -352,24 +466,3 @@ class ChatRequest
     [JsonPropertyName("systemPrompt")]
     public string SystemPrompt { get; set; } = "";
 }
-
-class StepInfo
-{
-    [JsonPropertyName("type")]
-    public string Type { get; set; } = "";
-
-    [JsonPropertyName("text")]
-    public string Text { get; set; } = "";
-
-    [JsonPropertyName("toolName")]
-    public string ToolName { get; set; } = "";
-
-    [JsonPropertyName("toolInput")]
-    public string ToolInput { get; set; } = "";
-
-    [JsonPropertyName("toolResult")]
-    public string ToolResult { get; set; } = "";
-
-    [JsonPropertyName("isError")]
-    public bool IsError { get; set; }
-}