"""Shell operation utilities for nanocode."""

import subprocess
from .display import DIM, RESET


def run_bash(cmd: str) -> str:
    """Run a shell command and return output.

    Args:
        cmd: Shell command to execute

    Returns:
        Command output (stdout and stderr combined)
    """
    proc = subprocess.Popen(
        cmd, shell=True,
        stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
        text=True
    )
    output_lines = []
    try:
        while True:
            line = proc.stdout.readline()
            if not line and proc.poll() is not None:
                break
            if line:
                print(f"  {DIM}│ {line.rstrip()}{RESET}", flush=True)
                output_lines.append(line)
        proc.wait(timeout=30)
    except subprocess.TimeoutExpired:
        proc.kill()
        output_lines.append("\n(timed out after 30s)")
    return "".join(output_lines).strip() or "(empty output)"