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

helper_dir=${SLOPTRAP_HELPER_DIR:-/run/sloptrap-helper}
queue_dir="$helper_dir/queue"
default_output=${SLOPTRAP_CAPTURE_DIR:-/codex/state/captures}
mkdir -p "$queue_dir" "$default_output"

if [[ ${1-} != "capture" ]]; then
  printf 'usage: slopcap capture --interface <iface> [--filter <expr>] [--output <path>] [--stdout]\n' >&2
  exit 2
fi
shift

iface=""
filter=""
output=""
stdout_mode=0

while [[ $# -gt 0 ]]; do
  case "$1" in
    --interface)
      shift
      [[ $# -gt 0 ]] || { printf 'slopcap: --interface requires a value\n' >&2; exit 2; }
      iface=$1
      ;;
    --filter)
      shift
      [[ $# -gt 0 ]] || { printf 'slopcap: --filter requires a value\n' >&2; exit 2; }
      filter=$1
      ;;
    --output)
      shift
      [[ $# -gt 0 ]] || { printf 'slopcap: --output requires a value\n' >&2; exit 2; }
      output=$1
      ;;
    --stdout)
      stdout_mode=1
      ;;
    *)
      printf 'slopcap: unsupported argument %s\n' "$1" >&2
      exit 2
      ;;
  esac
  shift
done

[[ -n $iface ]] || { printf 'slopcap: --interface is required\n' >&2; exit 2; }
if [[ -z $output && $stdout_mode -eq 0 ]]; then
  output="$default_output/capture-$(date +%s).pcap"
fi

request_dir=$(mktemp -d "$queue_dir/request.XXXXXX.req")
trap 'rm -rf "$request_dir"' EXIT INT TERM HUP
printf 'packet-capture\n' >"$request_dir/op"
printf '%s\n' "$iface" >"$request_dir/interface"
printf '%s\n' "$filter" >"$request_dir/filter"
printf '%s\n' "$output" >"$request_dir/output"
printf '%s\n' "$stdout_mode" >"$request_dir/stdout_mode"

stream_pid=""
if [[ $stdout_mode -eq 1 ]]; then
  touch "$request_dir/stdout"
  tail -f "$request_dir/stdout" &
  stream_pid=$!
fi

while [[ ! -f "$request_dir/status" ]]; do
  sleep 1
done

if [[ -n $stream_pid ]]; then
  kill "$stream_pid" >/dev/null 2>&1 || true
  wait "$stream_pid" >/dev/null 2>&1 || true
fi

if [[ $stdout_mode -eq 0 && -s "$request_dir/stdout" ]]; then
  cat "$request_dir/stdout"
fi
if [[ -s "$request_dir/stderr" ]]; then
  cat "$request_dir/stderr" >&2
fi

status=$(<"$request_dir/status")
exit "$status"