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

usage() {
  cat <<'EOF'
Usage: start_only_udp.sh [config_path]

Options via env:
  MYNETSPEEDER_SOCKS_HOST   SOCKS 监听地址，默认读取配置或 127.0.0.1
  MYNETSPEEDER_SOCKS_PORT   SOCKS 监听端口，默认读取配置或 19180
  MYNETSPEEDER_USER         运行用户，默认 mynetspeeder
  MYNETSPEEDER_LOG_MAX_MB    单个日志最大大小，默认 50
  MYNETSPEEDER_LOG_BACKUPS   日志轮转保留份数，默认 3
EOF
}

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(dirname "$SCRIPT_DIR")"
PACKAGE_PARENT="$(dirname "$ROOT_DIR")"
PACKAGE_NAME="$(basename "$ROOT_DIR")"

CONFIG_PATH="${1:-$ROOT_DIR/config.json}"
RUNTIME_USER="${MYNETSPEEDER_USER:-mynetspeeder}"
PID_FILE="/var/run/mynetspeeder-socks.pid"
LOG_FILE="/var/log/mynetspeeder-socks.log"
LOG_MAX_MB="${MYNETSPEEDER_LOG_MAX_MB:-50}"
LOG_BACKUPS="${MYNETSPEEDER_LOG_BACKUPS:-3}"

if [[ $EUID -ne 0 ]]; then
  echo "need root"
  exit 1
fi

if [[ ! -f "$CONFIG_PATH" ]]; then
  echo "config not found: $CONFIG_PATH"
  exit 1
fi

SOCKS_HOST_FROM_CONFIG=$(python3 - <<'PY' "$CONFIG_PATH"
import json, sys
cfg = json.load(open(sys.argv[1]))
print(cfg.get("socks_host", "127.0.0.1"))
PY
)
SOCKS_PORT_FROM_CONFIG=$(python3 - <<'PY' "$CONFIG_PATH"
import json, sys
cfg = json.load(open(sys.argv[1]))
port = int(cfg.get("socks_port", 19180) or 19180)
print(port if port > 0 else 19180)
PY
)
SOCKS_HOST="${MYNETSPEEDER_SOCKS_HOST:-$SOCKS_HOST_FROM_CONFIG}"
SOCKS_PORT="${MYNETSPEEDER_SOCKS_PORT:-$SOCKS_PORT_FROM_CONFIG}"

if ! [[ "$SOCKS_PORT" =~ ^[0-9]+$ ]]; then
  echo "socks port must be numeric"
  exit 1
fi

id -u "$RUNTIME_USER" >/dev/null 2>&1 || useradd --system --no-create-home --shell /usr/sbin/nologin "$RUNTIME_USER"
mkdir -p /var/log
touch "$LOG_FILE"
chown "$RUNTIME_USER":"$RUNTIME_USER" "$LOG_FILE"
if ! [[ "$LOG_MAX_MB" =~ ^[0-9]+$ ]] || ! [[ "$LOG_BACKUPS" =~ ^[0-9]+$ ]]; then
  echo "log limits must be numeric"
  exit 1
fi
LOG_MAX_BYTES=$((LOG_MAX_MB * 1024 * 1024))

wait_for_listen() {
  local host="$1"
  local port="$2"
  local log_file="$3"
  local log_pattern="$4"
  local label="$5"
  local timeout_sec="${6:-10}"
  local deadline=$((SECONDS + timeout_sec))
  local pattern
  pattern="${host//./\\.}:${port}( |$)"
  while (( SECONDS < deadline )); do
    if ss -H -lntp 2>/dev/null | grep -qE "$pattern"; then
      return 0
    fi
    if [[ -f "$log_file" ]] && grep -qE "$log_pattern" "$log_file" 2>/dev/null; then
      return 0
    fi
    sleep 0.2
  done
  echo "$label failed to listen"
  return 1
}

pkill -f 'python3 -m mynetspeeder socks' || true

runuser -u "$RUNTIME_USER" -- bash -lc "export PYTHONUNBUFFERED=1; export PYTHONPATH=${PACKAGE_PARENT}; cd ${PACKAGE_PARENT} && exec nohup python3 -m ${PACKAGE_NAME} socks --listen-host ${SOCKS_HOST} --listen-port ${SOCKS_PORT} --config ${CONFIG_PATH} 2>&1 | python3 ${ROOT_DIR}/scripts/rotate-log.py ${LOG_FILE} ${LOG_MAX_BYTES} ${LOG_BACKUPS}" &
SOCKS_PID=$!
echo "$SOCKS_PID" > "$PID_FILE"

if ! wait_for_listen "$SOCKS_HOST" "$SOCKS_PORT" "$LOG_FILE" "socks5 listening on" "socks" 15; then
  tail -n 50 "$LOG_FILE" || true
  exit 1
fi

echo "mynetspeeder udp+socks mode started on ${SOCKS_HOST}:${SOCKS_PORT}"
echo "tcp: direct"
echo "udp: use socks5 udp associate for project acceleration"
echo "pid file: $PID_FILE"
echo "log file: $LOG_FILE"
echo "log max: ${LOG_MAX_MB}MB x ${LOG_BACKUPS}"