feat(cli): add pull request creation with AI-generated messages (#2)

Add a new `gai pr` subcommand that generates pull request titles and descriptions using AI, then creates the PR via GitHub CLI (`gh`) or Gitea CLI (`tea`). This extends the existing commit-generation system by reusing retry logic and prompt infrastructure, and introduces a `callAI` function that returns raw output (instead of pre-cleaned messages) to support structured PR responses.

Reviewed-on: #2

src/ai.ts

@@ -39,11 +39,10 @@ async function sleep(ms: number) {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
-export async function generateCommitMessage(
+export async function callAI(
   config: Config,
   systemPrompt: string,
   userPrompt: string,
-  retries = MAX_RETRIES,
 ): Promise<string> {
   const url = `${config.apiBase.replace(/\/$/, "")}/chat/completions`;
 
@@ -52,7 +51,7 @@ export async function generateCommitMessage(
     { role: "user", content: userPrompt },
   ];
 
-  for (let attempt = 1; attempt <= retries; attempt++) {
+  for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
     try {
       const response = await fetch(url, {
         method: "POST",
@@ -70,7 +69,7 @@ export async function generateCommitMessage(
 
       if (!response.ok) {
         const text = await response.text();
-        if (response.status === 429 && attempt < retries) {
+        if (response.status === 429 && attempt < MAX_RETRIES) {
           await sleep(RETRY_DELAY * attempt);
           continue;
         }
@@ -89,7 +88,7 @@ export async function generateCommitMessage(
       const finishReason = data.choices?.[0]?.finish_reason;
 
       if (raw && raw.trim()) {
-        return cleanMessage(raw);
+        return raw;
       }
 
       if (finishReason === "length") {
@@ -102,22 +101,53 @@ export async function generateCommitMessage(
         throw new Error("Response blocked by content filter.");
       }
 
-      if (attempt < retries) {
+      if (attempt < MAX_RETRIES) {
         await sleep(RETRY_DELAY * attempt);
         continue;
       }
 
       throw new Error(
-        `Empty response from AI after ${retries} attempts. finish_reason: ${finishReason ?? "unknown"}`,
+        `Empty response from AI after ${MAX_RETRIES} attempts. finish_reason: ${finishReason ?? "unknown"}`,
       );
     } catch (err) {
-      if (attempt >= retries) throw err;
+      if (attempt >= MAX_RETRIES) throw err;
       if (err instanceof Error && err.message.startsWith("API error")) throw err;
       if (err instanceof Error && err.message.includes("max_tokens")) throw err;
-      if (err instanceof Error && err.message.includes("content filter")) throw err;
+      if (err instanceof Error && err.message.includes("content filter"))
+        throw err;
       await sleep(RETRY_DELAY * attempt);
     }
   }
 
-  throw new Error("Failed to generate commit message");
+  throw new Error("Failed to generate response");
+}
+
+export async function generateCommitMessage(
+  config: Config,
+  systemPrompt: string,
+  userPrompt: string,
+): Promise<string> {
+  const raw = await callAI(config, systemPrompt, userPrompt);
+  return cleanMessage(raw);
+}
+
+export async function generatePRMessage(
+  config: Config,
+  systemPrompt: string,
+  userPrompt: string,
+): Promise<{ title: string; body: string }> {
+  const raw = await callAI(config, systemPrompt, userPrompt);
+  const cleaned = cleanMessage(raw);
+
+  const lines = cleaned.split("\n");
+  const title = lines[0]?.trim() || "Update";
+  let bodyStart = 1;
+
+  while (bodyStart < lines.length && lines[bodyStart]?.trim() === "") {
+    bodyStart++;
+  }
+
+  const body = lines.slice(bodyStart).join("\n").trim();
+
+  return { title, body };
 }