#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
# Keep Black cache local to avoid AppData lock/permission errors on Windows.
export BLACK_CACHE_DIR="${BLACK_CACHE_DIR:-$ROOT_DIR/.tmp/black-cache}"
mkdir -p "$BLACK_CACHE_DIR"

# CRITICAL: Always prefer project-local venv interpreter for Black.
# Without this, Windows can accidentally pick global Python (e.g. C:\Program Files\Python312)
# where `black` is not installed, causing flaky pre-commit failures.
# DO NOT change this back to "python/python3 from PATH first" unless you also
# guarantee black is installed in every global interpreter used by contributors.

is_wsl() {
  grep -qiE "(microsoft|wsl)" /proc/version 2>/dev/null
}

can_use_python() {
  local candidate="$1"
  [ -f "$candidate" ] || return 1
  "$candidate" -c "import sys; print(sys.executable)" >/dev/null 2>&1
}

select_venv_dirs() {
  local dirs=()
  if [ -n "${OPENCLAW_TEST_VENV:-}" ]; then
    dirs+=("$OPENCLAW_TEST_VENV")
  fi
  if is_wsl; then
    dirs+=("$ROOT_DIR/.venv-wsl")
  fi
  dirs+=("$ROOT_DIR/.venv")
  printf '%s\n' "${dirs[@]}"
}

check_venv_dir() {
  local dir="$1"
  if can_use_python "$dir/Scripts/python.exe"; then
    PY_CMD="$dir/Scripts/python.exe"
    return 0
  fi
  if can_use_python "$dir/bin/python"; then
    PY_CMD="$dir/bin/python"
    return 0
  fi
  return 1
}

while IFS= read -r vdir; do
  [ -n "$vdir" ] || continue
  if [ -d "$vdir" ]; then
    if check_venv_dir "$vdir"; then
      break
    fi
    # IMPORTANT:
    # If a preferred project venv exists but is unusable, fail fast instead of
    # silently falling back to random global Python (prevents environment drift).
    echo "ERROR: project venv exists but Python is unusable: $vdir" >&2
    echo "Recreate this venv and retry." >&2
    exit 1
  fi
done < <(select_venv_dirs)

if [ -n "${PY_CMD:-}" ]; then
  :
elif command -v python >/dev/null 2>&1; then
  # Fallback chain only for environments that intentionally do not use .venv.
  PY_CMD="$(command -v python)"
elif command -v python3 >/dev/null 2>&1; then
  PY_CMD="$(command -v python3)"
else
  echo "ERROR: python interpreter not found (need python or python3 in PATH)." >&2
  exit 127
fi

# Ensure black exists in the selected interpreter.
# This self-heals first-run environments and prevents recurring "No module named black".
if ! "$PY_CMD" -c "import black" >/dev/null 2>&1; then
  echo "[black-single] INFO: installing black==24.1.1 into selected Python env ..." >&2
  "$PY_CMD" -m pip install black==24.1.1 >/dev/null
fi

exec "$PY_CMD" -B scripts/precommit_black_single.py "$@"