// TTY detection for Bun compatibility.
// Bun does not set process.stdin.isTTY, so we use fs.fstatSync.

import { fstatSync } from "node:fs";

let _stdinTTY: boolean | null = null;

export function initTTY(): void {
  if (_stdinTTY !== null) return;

  try {
    // fd 0 = stdin. On Unix, a TTY is a character device.
    const stat = fstatSync(0);
    _stdinTTY = stat.isCharacterDevice();
  } catch {
    _stdinTTY = false;
  }
}

export function isStdinTTY(): boolean {
  if (_stdinTTY === null) initTTY();
  return _stdinTTY!;
}

export function isStdoutTTY(): boolean {
  // Use a heuristic for stdout — check if we're in a terminal
  if (process.env.TERM || process.env.TERM_PROGRAM) return true;
  if (process.env.NO_COLOR) return false;
  // Try fstat on fd 1 (stdout)
  try {
    const stat = fstatSync(1);
    return stat.isCharacterDevice();
  } catch {
    return false;
  }
}