import { execFile } from "node:child_process";
import { mkdir } from "node:fs/promises";
import { join, resolve } from "node:path";
import { promisify } from "node:util";

const execFileAsync = promisify(execFile);
export interface Worktree { path: string; baseCommit: string }

async function git(cwd: string, args: string[]): Promise<string> {
  const { stdout } = await execFileAsync("git", args, { cwd, encoding: "utf8" });
  return stdout.trim();
}

export async function createWorktree(repo: string, root: string, runId: string, nodeId: string): Promise<Worktree> {
  if (!/^[\w-]+$/.test(runId) || !/^[\w-]+$/.test(nodeId)) throw new Error("Invalid worktree identifier");
  const baseCommit = await git(repo, ["rev-parse", "HEAD"]);
  const path = resolve(root, runId, nodeId);
  await mkdir(join(root, runId), { recursive: true });
  await git(repo, ["worktree", "add", "--detach", path, baseCommit]);
  return { path, baseCommit };
}

export async function removeWorktree(repo: string, worktree: string): Promise<void> {
  await git(repo, ["worktree", "remove", "--force", worktree]);
}