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

# CASAN H4 tool-execution guard.
# Runs a command under a hard wall-clock timeout so a runaway/hung tool call
# cannot block the pipeline indefinitely. Portable (uses `timeout` if present,
# else a perl alarm) — macOS has no coreutils `timeout` by default.
#
# Scope (honest): this enforces a TIMEOUT only. True kernel sandboxing
# (namespaces/seccomp/network isolation) requires running the tool inside a
# container and is documented as a production requirement — it is NOT emulated
# here. Do not present this as full sandboxing.
#
# Usage: tool-exec.sh <timeout-seconds> -- <command...>
# Exit: command's exit code, or 124 on timeout.

TIMEOUT="${1:-${CASAN_TOOL_TIMEOUT_SECONDS:-30}}"
shift || true
if [[ "${1:-}" == "--" ]]; then shift; fi
if [[ "$#" -eq 0 ]]; then
  echo "Usage: tool-exec.sh <timeout-seconds> -- <command...>" >&2
  exit 64
fi

if command -v timeout >/dev/null 2>&1; then
  timeout "$TIMEOUT" "$@"
  rc=$?
elif command -v perl >/dev/null 2>&1; then
  perl -e 'my $t=shift; $SIG{ALRM}=sub{exit 124}; alarm($t); exec @ARGV or exit 127;' "$TIMEOUT" "$@"
  rc=$?
else
  # SEC-15: no timeout backend. In enforced mode REFUSE (fail-closed) rather than
  # run a command that could hang the pipeline; dev warns and proceeds.
  if [[ "${CASAN_PROFILE:-}" == "prod" || "${CASAN_TOOL_EXEC_STRICT:-}" == "1" ]]; then
    echo "TOOL_EXEC_NO_TIMEOUT_BACKEND refusing (fail-closed: install coreutils timeout or perl)" >&2
    exit 2
  fi
  echo "TOOL_EXEC_NO_TIMEOUT_BACKEND (dev: running without timeout)" >&2
  "$@"
  rc=$?
fi

if [[ "$rc" -eq 124 || "$rc" -eq 142 ]]; then
  echo "TOOL_EXEC_TIMEOUT after ${TIMEOUT}s" >&2
  exit 124
fi
exit "$rc"