feat: log llm runtime responses

src/lib/llm/client.ts

@@ -1,12 +1,19 @@
 import OpenAI from "openai";
 import type { z } from "zod";
 
+export type LlmTaskName =
+  | "unknown"
+  | "fact_extractor"
+  | "article_optimizer"
+  | "quality_inspector"
+  | "targeted_rewriter";
+
 export interface GenerateInput {
   system?: string;
   prompt: string;
   model?: string;
   temperature?: number;
-  task?: string;
+  task?: LlmTaskName;
 }
 
 export interface GenerateValidatedJsonInput<T> extends GenerateInput {
@@ -77,7 +84,16 @@ function getTask(input: GenerateInput) {
   return input.task?.trim() || "unknown";
 }
 
-function truncateRaw(value: string, maxLength = 4000) {
+function getRawLogLimit() {
+  const parsed = Number(process.env.LLM_LOG_RAW_LIMIT ?? "4000");
+  return Number.isFinite(parsed) && parsed >= 0 ? parsed : 4000;
+}
+
+function stringifyForLog(value: unknown) {
+  return typeof value === "string" ? value : JSON.stringify(value);
+}
+
+function truncateRaw(value: string, maxLength = getRawLogLimit()) {
   return value.length > maxLength
     ? `${value.slice(0, maxLength)}...[truncated ${value.length - maxLength} chars]`
     : value;
@@ -195,8 +211,17 @@ export async function generateValidatedJson<T>({
     return null;
   }
 
+  const status = getLlmProviderStatus();
+  const startedAt = Date.now();
+  console.info(
+    `[llm:start] provider=${status.provider} model=${input.model ?? status.model} task=${task}`,
+  );
+
   try {
     const generated = await generateJsonForValidation<unknown>(input);
+    console.info(
+      `[llm:response] task=${task} duration_ms=${Date.now() - startedAt} raw=${truncateRaw(stringifyForLog(generated))}`,
+    );
     const parsed = schema.safeParse(generated);
     if (parsed.success) {
       console.info(`[llm:validated] task=${task} ok=true`);
@@ -206,8 +231,12 @@ export async function generateValidatedJson<T>({
       `[llm:validated] task=${task} ok=false zod_error=${quoteLogValue(summarizeZodError(parsed.error))}`,
     );
     return null;
-  } catch {
+  } catch (error) {
     console.info(`[llm:validated] task=${task} ok=false reason=provider_error`);
+    const message = error instanceof Error ? error.message : String(error);
+    console.warn(
+      `[llm:error] task=${task} duration_ms=${Date.now() - startedAt} message=${quoteLogValue(message)}`,
+    );
     return null;
   }
 }