# shell_runner.py
"""
Shell Runner - Execution engine for PowerShell scripts.

This module provides utilities to run PowerShell scripts in a subprocess,
configuring the environment via mcp_env.toml. It handles timeouts,
logging, and optional QA/patch callbacks for error recovery.
"""
import os
import shutil
import subprocess

from pathlib import Path
from typing  import Callable, Optional

try:
 import tomllib
except ImportError:
 import tomli as tomllib  # type: ignore[no-redef]

TIMEOUT_SECONDS: int = 60
_ENV_CONFIG: dict = {}


def _load_env_config() -> dict:
 """Load mcp_env.toml from project root or environment variable."""
 env_path = os.environ.get("SLOP_MCP_ENV")
 if env_path and Path(env_path).exists():
  with open(env_path, "rb") as f:
   return tomllib.load(f)
 candidates = [
  Path(__file__).parent / "mcp_env.toml",
  Path(__file__).parent.parent / "mcp_env.toml",
 ]
 for p in candidates:
  if p.exists():
   with open(p, "rb") as f:
    return tomllib.load(f)
 return {}

def _build_subprocess_env() -> dict[str, str]:
 """Build environment dictionary for subprocess with overrides from mcp_env.toml."""
 global _ENV_CONFIG
 if not _ENV_CONFIG:
  _ENV_CONFIG = _load_env_config()
 env = os.environ.copy()
 # Apply [path].prepend entries
 prepend_dirs = _ENV_CONFIG.get("path", {}).get("prepend", [])
 if prepend_dirs:
  env["PATH"] = os.pathsep.join(prepend_dirs) + os.pathsep + env.get("PATH", "")
  # Apply [env] key-value pairs, expanding ${VAR} references
 for key, val in _ENV_CONFIG.get("env", {}).items():
  env[key] = os.path.expandvars(str(val))
 return env

def run_powershell(script: str, base_dir: str, qa_callback: Optional[Callable[[str], str]] = None, patch_callback: Optional[Callable[[str, str], Optional[str]]] = None) -> str:
 """
 Run a PowerShell script with working directory set to base_dir.
 Returns a string combining stdout, stderr, and exit code.
 Environment is configured via mcp_env.toml (project root).
 If qa_callback is provided and the command fails or has stderr,
 the callback is called with the stderr content and its result is appended.
 If patch_callback is provided, it receives (error, file_context) and returns patch text.
 [C: tests/test_tier4_interceptor.py:test_run_powershell_no_qa_callback_on_success, tests/test_tier4_interceptor.py:test_run_powershell_optional_qa_callback, tests/test_tier4_interceptor.py:test_run_powershell_qa_callback_on_failure, tests/test_tier4_interceptor.py:test_run_powershell_qa_callback_on_stderr_only]
 """
 safe_dir:    str           = str(base_dir).replace("'", "''")
 full_script: str           = f"Set-Location -LiteralPath '{safe_dir}'\n{script}"
 exe:         Optional[str] = next((x for x in ["powershell.exe", "pwsh.exe", "powershell", "pwsh"] if shutil.which(x)), None)
 if not exe: return "ERROR: Neither powershell nor pwsh found in PATH"
 try:
  process = subprocess.Popen(
   [exe, "-NoProfile", "-NonInteractive", "-Command", full_script],
   stdin  = subprocess.DEVNULL,
   stdout = subprocess.PIPE, stderr=subprocess.PIPE, text=True,
   cwd    = base_dir, env=_build_subprocess_env(),
  )
  stdout, stderr = process.communicate(timeout=TIMEOUT_SECONDS)
  parts: list[str] = []
  if stdout.strip(): parts.append(f"STDOUT:\n{stdout.strip()}")
  if stderr.strip(): parts.append(f"STDERR:\n{stderr.strip()}")
  parts.append(f"EXIT CODE: {process.returncode}")
  if (process.returncode != 0 or stderr.strip()) and qa_callback:
   qa_analysis: Optional[str] = qa_callback(stderr.strip())
   if qa_analysis:
    parts.append(f"\nQA ANALYSIS:\n{qa_analysis}")
  if patch_callback and (process.returncode != 0 or stderr.strip()):
   patch_text = patch_callback(stderr.strip(), base_dir)
   if patch_text:
    parts.append(f"\nAUTO_PATCH:\n{patch_text}")
  return "\n".join(parts)
 except subprocess.TimeoutExpired:
  if 'process' in locals() and process:
   subprocess.run(["taskkill", "/F", "/T", "/PID", str(process.pid)], capture_output=True)
  return f"ERROR: timed out after {TIMEOUT_SECONDS}s"
 except KeyboardInterrupt:
  if 'process' in locals() and process:
   subprocess.run(["taskkill", "/F", "/T", "/PID", str(process.pid)], capture_output=True)
  raise
 except Exception as e:
  if 'process' in locals() and process:
   subprocess.run(["taskkill", "/F", "/T", "/PID", str(process.pid)], capture_output=True)
  return f"ERROR: {e}"
