feat(cli): add gai pr subcommand for AI-powered pull request creation

index.ts

@@ -19,6 +19,18 @@ import { generateCommitMessage } from "./src/ai";
 import { copyToClipboard } from "./src/clipboard";
 import { BOLD, GREEN, YELLOW, CYAN, RED, DIM, RESET } from "./src/terminal";
 import type { Config } from "./src/types";
+import {
+  getDefaultBranch,
+  getBranchName,
+  getBranchCommits,
+  getBranchDiff,
+  detectPlatform,
+  checkCLI,
+  checkAuth,
+  createPR,
+} from "./src/pr";
+import { PR_SYSTEM_PROMPT, buildPRPrompt } from "./src/prompt";
+import { generatePRMessage } from "./src/ai";
 
 const args = process.argv.slice(2);
 
@@ -31,6 +43,8 @@ ${BOLD}Usage:${RESET}
   gai commit         Generate commit message for staged/changed files
   gai commit --auto  Auto-stage all changed files
   gai commit -d      Generate message without committing
+  gai pr             Create a PR with AI-generated title and body
+  gai pr --draft     Create a draft PR
   gai config         Configure API settings
   gai --help         Show this help message
   gai --version      Show version
@@ -277,6 +291,7 @@ interface MenuAction {
 
 const MENU_ACTIONS: MenuAction[] = [
   { key: "commit", label: "commit", description: "Generate AI commit message" },
+  { key: "pr", label: "pr", description: "Create a PR with AI-generated title" },
   { key: "config", label: "config", description: "Configure API settings" },
 ];
 
@@ -385,6 +400,8 @@ async function showMenu(): Promise<void> {
 
         if (selected.key === "commit") {
           handleCommit(false, false).then(resolve);
+        } else if (selected.key === "pr") {
+          handlePR(false).then(resolve);
         } else if (selected.key === "config") {
           handleConfig().then(resolve);
         } else {
@@ -517,6 +534,153 @@ async function handleCommit(autoMode: boolean, dryRun: boolean): Promise<void> {
   }
 }
 
+async function handlePR(draft: boolean): Promise<void> {
+  const config = await loadConfig();
+
+  if (!config.apiKey) {
+    console.error(
+      `  ${RED}Error: API key not set. Run ${BOLD}gai config${RESET}${RED} to configure.${RESET}`,
+    );
+    process.exit(1);
+  }
+
+  if (!(await isGitRepo())) {
+    console.error(`  ${RED}Error: Not a git repository.${RESET}`);
+    process.exit(1);
+  }
+
+  const platform = await detectPlatform();
+  if (!platform) {
+    console.error(
+      `  ${RED}Error: Could not detect GitHub or Gitea from origin remote URL.${RESET}`,
+    );
+    process.exit(1);
+  }
+
+  const platformLabel = platform === "github" ? "GitHub" : "Gitea";
+  console.log(`  Remote platform: ${CYAN}${platformLabel}${RESET}`);
+
+  const cliError = checkCLI(platform);
+  if (cliError) {
+    console.error(`  ${RED}Error: ${cliError}${RESET}`);
+    process.exit(1);
+  }
+
+  const authError = await checkAuth(platform);
+  if (authError) {
+    console.error(`  ${RED}Error: ${authError}${RESET}`);
+    process.exit(1);
+  }
+
+  const baseBranch = await getDefaultBranch();
+  const branchName = await getBranchName();
+
+  if (branchName === baseBranch) {
+    console.error(
+      `  ${RED}Error: You are on the default branch (${baseBranch}). Switch to a feature branch first.${RESET}`,
+    );
+    process.exit(1);
+  }
+
+  console.log(
+    `  Branch: ${CYAN}${branchName}${RESET} → base: ${CYAN}${baseBranch}${RESET}`,
+  );
+
+  const commits = await getBranchCommits(baseBranch);
+
+  if (commits.length === 0) {
+    console.error(
+      `  ${RED}Error: No commits on ${branchName} compared to ${baseBranch}. Commit something first.${RESET}`,
+    );
+    process.exit(1);
+  }
+
+  console.log(
+    `  ${commits.length} commit${commits.length > 1 ? "s" : ""} on this branch`,
+  );
+
+  const diff = await getBranchDiff(baseBranch);
+  if (!diff) {
+    console.error(`  ${RED}Error: No diff from base branch.${RESET}`);
+    process.exit(1);
+  }
+
+  const MAX_DIFF_SIZE = 15000;
+  const truncatedDiff =
+    diff.length > MAX_DIFF_SIZE
+      ? diff.substring(0, MAX_DIFF_SIZE) + "\n... (truncated)"
+      : diff;
+
+  const repoRoot = await getRepoRoot();
+  const projectCtx = await collectProjectContext(repoRoot);
+
+  const userPrompt = buildPRPrompt({
+    readme: projectCtx.readme,
+    packageDescription: projectCtx.packageDescription,
+    structure: projectCtx.structure,
+    branchName,
+    baseBranch,
+    branchCommits: commits,
+    diff: truncatedDiff,
+  });
+
+  console.log("\n  Generating PR title...");
+
+  let title: string;
+  let body: string;
+  try {
+    const result = await generatePRMessage(config, PR_SYSTEM_PROMPT, userPrompt);
+    title = result.title;
+    body = result.body;
+  } catch (err) {
+    console.error(
+      `  ${RED}AI request failed: ${err instanceof Error ? err.message : err}${RESET}`,
+    );
+    process.exit(1);
+  }
+
+  console.log(`\n  ${BOLD}Generated PR:${RESET}`);
+  console.log(`    Title: ${GREEN}${title}${RESET}`);
+  if (body) {
+    console.log(
+      `    Body:  ${DIM}${body.replace(/\n/g, "\n           ")}${RESET}`,
+    );
+  }
+  console.log("");
+
+  const answer = await ask(`  Create this PR? [${GREEN}Y${RESET}/n/e] `);
+  const lower = answer.toLowerCase();
+
+  if (lower === "n") {
+    console.log("  Aborted.");
+    return;
+  }
+
+  if (lower === "e") {
+    const newTitle = await ask("  Title: ");
+    const newBody = await ask("  Body (optional): ");
+    if (!newTitle.trim()) {
+      console.log("  Aborted.");
+      return;
+    }
+    title = newTitle;
+    body = newBody;
+  }
+
+  console.log(`\n  Creating PR...`);
+
+  try {
+    const url = await createPR(platform, title, body, baseBranch, draft);
+    console.log(`  ${GREEN}${BOLD}✔ PR created!${RESET}`);
+    console.log(`    ${CYAN}${url}${RESET}`);
+  } catch (err) {
+    console.error(
+      `  ${RED}PR creation failed: ${err instanceof Error ? err.message : err}${RESET}`,
+    );
+    process.exit(1);
+  }
+}
+
 async function main() {
   if (args.includes("--help") || args.includes("-h")) {
     showHelp();
@@ -547,6 +711,12 @@ async function main() {
     return;
   }
 
+  if (subcommand === "pr") {
+    const draft = args.includes("--draft");
+    await handlePR(draft);
+    return;
+  }
+
   if (!subcommand) {
     await showMenu();
     return;