feat(llm 對話): 新增 prompt builder 與 few-shot 範例組裝,強化 Claude 對話品質

apps/api/src/llm/claude-provider.service.ts

@@ -1,19 +1,101 @@
 import { Injectable } from "@nestjs/common";
 import type { LLMProvider } from "./llm-provider.js";
 import type { GenerationContext, GeneratedResponse } from "./types.js";
+import { buildMessages } from "./prompt-builder.js";
+import { extractActions } from "./action-markup.js";
 
-const NOT_IMPLEMENTED_MESSAGE = "ClaudeProvider 尚未實作（R-3 會接上真實 Claude API）";
+interface OpenAiCompatibleChoice {
+  message?: { content?: string };
+  delta?: { content?: string };
+}
+interface OpenAiCompatibleResponse {
+  choices?: OpenAiCompatibleChoice[];
+}
 
-// F-2 ClaudeProvider 空殼：R-3 才會實作真實呼叫，目前僅回報未實作。
+function baseUrl(): string {
+  return process.env.CLAUDE_BASE_URL ?? "http://localhost:3000/api/v1";
+}
+
+function apiKey(): string {
+  const key = process.env.CLAUDE_API_KEY;
+  if (!key) {
+    throw new Error("CLAUDE_API_KEY 未設定，LLM_PROVIDER=claude 需要這個環境變數才能呼叫真實 API");
+  }
+  return key;
+}
+
+function model(): string {
+  return process.env.CLAUDE_MODEL ?? "claude-sonnet-4-5";
+}
+
+async function requestChatCompletion(body: Record<string, unknown>): Promise<Response> {
+  const res = await fetch(`${baseUrl()}/chat/completions`, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      Authorization: `Bearer ${apiKey()}`,
+    },
+    body: JSON.stringify(body),
+  });
+  if (!res.ok) {
+    const text = await res.text().catch(() => "");
+    throw new Error(`ClaudeProvider 呼叫失敗（HTTP ${res.status}）：${text.slice(0, 500)}`);
+  }
+  return res;
+}
+
+// R-3：把 F-2 的空殼換成真的呼叫。這個部署走 CLIProxy（分散式派工代理，見
+// gitea.jsc.idv.tw/jiantw83/CLIProxy）提供的 OpenAI 相容端點，而不是直連
+// api.anthropic.com——底層仍是 Claude，只是多一層派工代理，對這個介面
+// （LLMProvider.generate/stream）完全透明，切換供應商不需要動任何呼叫端程式碼。
 @Injectable()
 export class ClaudeProvider implements LLMProvider {
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  async generate(_context: GenerationContext): Promise<GeneratedResponse> {
-    throw new Error(NOT_IMPLEMENTED_MESSAGE);
+  async generate(context: GenerationContext): Promise<GeneratedResponse> {
+    const res = await requestChatCompletion({
+      model: model(),
+      messages: buildMessages(context),
+      stream: false,
+    });
+    const json = (await res.json()) as OpenAiCompatibleResponse;
+    const text = json.choices?.[0]?.message?.content ?? "";
+    if (!text) {
+      throw new Error("ClaudeProvider 回應內容為空（choices[0].message.content 缺失）");
+    }
+    return { text, actions: extractActions(text) };
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars, require-yield
-  async *stream(_context: GenerationContext): AsyncIterable<string> {
-    throw new Error(NOT_IMPLEMENTED_MESSAGE);
+  async *stream(context: GenerationContext): AsyncIterable<string> {
+    const res = await requestChatCompletion({
+      model: model(),
+      messages: buildMessages(context),
+      stream: true,
+    });
+    if (!res.body) {
+      throw new Error("ClaudeProvider 串流回應沒有 body");
+    }
+    const reader = res.body.getReader();
+    const decoder = new TextDecoder();
+    let buffer = "";
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      buffer += decoder.decode(value, { stream: true });
+      const lines = buffer.split("\n");
+      buffer = lines.pop() ?? "";
+      for (const line of lines) {
+        const trimmed = line.trim();
+        if (!trimmed.startsWith("data:")) continue;
+        const payload = trimmed.slice("data:".length).trim();
+        if (payload === "[DONE]") return;
+        let chunk: OpenAiCompatibleResponse;
+        try {
+          chunk = JSON.parse(payload);
+        } catch {
+          continue;
+        }
+        const delta = chunk.choices?.[0]?.delta?.content;
+        if (delta) yield delta;
+      }
+    }
   }
 }