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

IFACE="${1:-}"
TARGET="${2:-}"
ENV_FILE="${GREE_CONTROLLER_ENV_FILE:-/etc/gree-controller.env}"

if [[ -z "$IFACE" && -r "$ENV_FILE" ]]; then
  IFACE="$(sed -n 's/^GREE_CONTROLLER_GREE_INTERFACE=//p' "$ENV_FILE" | tail -n1)"
fi
if [[ -z "$TARGET" && -r "$ENV_FILE" ]]; then
  TARGET="$(sed -n 's/^GREE_CONTROLLER_DISCOVERY_BROADCAST=//p' "$ENV_FILE" | tail -n1)"
  TARGET="${TARGET%:*}"
fi

if [[ -z "$IFACE" ]]; then
  echo "Usage: $0 <interface> [broadcast-ip]" >&2
  echo "Example: $0 eth1 10.87.65.127" >&2
  exit 2
fi

echo "==> Interface"
ip -br addr show dev "$IFACE"
echo

echo "==> IPv4 details"
ip -4 addr show dev "$IFACE"
echo

echo "==> Routes"
ip route show dev "$IFACE"
echo

if [[ -n "$TARGET" ]]; then
  echo "==> Route to discovery target $TARGET"
  ip route get "$TARGET" || true
  echo
fi

echo "==> GREE Controller environment"
if [[ -r "$ENV_FILE" ]]; then
  grep -E '^(GREE_CONTROLLER_GREE_INTERFACE|GREE_CONTROLLER_DISCOVERY_BROADCAST|GREE_CONTROLLER_SIMULATE|GREE_CONTROLLER_AUTO_SEED)=' "$ENV_FILE" || true
else
  echo "$ENV_FILE is not readable"
fi

echo
if command -v tcpdump >/dev/null 2>&1; then
  echo "Capture discovery traffic with:"
  echo "  tcpdump -ni $IFACE -vv 'udp port 7000'"
else
  echo "tcpdump is not installed. Optional: apt-get install tcpdump"
fi