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

SERVICE_NAME="vmess-domain-rotator"
APP_DIR="/opt/vmess-domain-rotator"
RUN_USER="vmessrotator"
RUN_GROUP="vmessrotator"
APP_DIR_SET="0"
RUN_USER_SET="0"
RUN_GROUP_SET="0"
INTERVAL="12h"
INSTALL_DEPS="1"
OVERWRITE_CONFIG="0"

usage() {
  cat <<'EOF'
Usage: sudo bash scripts/install_debian.sh [options]

Default behavior:
  - If current source dir is a git repo and --app-dir is not set, install in-place
    (service runs directly from this repo so auto-commit works on your real git repo).
  - If --app-dir is set, files are copied into that directory.

Options:
  --app-dir <path>         Install directory (default: /opt/vmess-domain-rotator)
  --user <name>            Service user (default: vmessrotator)
  --group <name>           Service group (default: vmessrotator)
  --interval <value>       Timer interval, e.g. 12h/10min (default: 12h)
  --no-install-deps        Skip apt dependency install
  --overwrite-config       Overwrite existing config.json in app dir
  -h, --help               Show help

Examples:
  sudo bash scripts/install_debian.sh
  sudo bash scripts/install_debian.sh --app-dir /opt/vmess-domain-rotator
  sudo bash scripts/install_debian.sh --user root --group root --interval 10min
EOF
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --app-dir)
      APP_DIR="$2"
      APP_DIR_SET="1"
      shift 2
      ;;
    --user)
      RUN_USER="$2"
      RUN_USER_SET="1"
      shift 2
      ;;
    --group)
      RUN_GROUP="$2"
      RUN_GROUP_SET="1"
      shift 2
      ;;
    --interval)
      INTERVAL="$2"
      shift 2
      ;;
    --no-install-deps)
      INSTALL_DEPS="0"
      shift
      ;;
    --overwrite-config)
      OVERWRITE_CONFIG="1"
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "Unknown option: $1" >&2
      usage
      exit 1
      ;;
  esac
done

if [[ "$(id -u)" -ne 0 ]]; then
  echo "Please run as root (use sudo)." >&2
  exit 1
fi

SOURCE_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
DEPLOY_MODE="copy"

if [[ "$APP_DIR_SET" != "1" ]] && git -C "$SOURCE_DIR" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  APP_DIR="$SOURCE_DIR"
  DEPLOY_MODE="in-place"

  if [[ -n "${SUDO_USER:-}" ]] && [[ "$RUN_USER_SET" != "1" ]]; then
    RUN_USER="$SUDO_USER"
  fi

  if [[ -n "${SUDO_USER:-}" ]] && [[ "$RUN_GROUP_SET" != "1" ]]; then
    RUN_GROUP="$(id -gn "$SUDO_USER")"
  fi
fi

if [[ "$INSTALL_DEPS" == "1" ]]; then
  export DEBIAN_FRONTEND=noninteractive
  apt-get update -y
  apt-get install -y python3 ca-certificates git
fi

if [[ "$RUN_USER" != "root" ]]; then
  if ! getent group "$RUN_GROUP" >/dev/null 2>&1; then
    groupadd --system "$RUN_GROUP"
  fi
  if ! id -u "$RUN_USER" >/dev/null 2>&1; then
    useradd --system --home-dir "$APP_DIR" --create-home --shell /usr/sbin/nologin --gid "$RUN_GROUP" "$RUN_USER"
  fi
fi

mkdir -p "$APP_DIR"

if [[ "$DEPLOY_MODE" == "copy" ]]; then
  CONFIG_BACKUP=""
  if [[ "$OVERWRITE_CONFIG" != "1" && -f "$APP_DIR/config.json" ]]; then
    CONFIG_BACKUP="$(mktemp)"
    cp "$APP_DIR/config.json" "$CONFIG_BACKUP"
  fi

  tar -C "$SOURCE_DIR" \
    --exclude='.git' \
    --exclude='.DS_Store' \
    --exclude='__pycache__' \
    -cf - . | tar -C "$APP_DIR" -xf -

  if [[ -n "$CONFIG_BACKUP" ]]; then
    cp "$CONFIG_BACKUP" "$APP_DIR/config.json"
    rm -f "$CONFIG_BACKUP"
  fi
fi

mkdir -p "$APP_DIR/runtime"
chmod +x "$APP_DIR/scripts/run_update_and_commit.sh" "$APP_DIR/scripts/install_debian.sh" "$APP_DIR/scripts/uninstall_debian.sh" || true

if [[ "$RUN_USER" != "root" ]]; then
  if [[ "$DEPLOY_MODE" == "in-place" ]]; then
    chown -R "$RUN_USER:$RUN_GROUP" "$APP_DIR/runtime"
  else
    chown -R "$RUN_USER:$RUN_GROUP" "$APP_DIR"
  fi
fi

if [[ "$DEPLOY_MODE" == "copy" ]] && ! git -C "$APP_DIR" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  git -C "$APP_DIR" init
fi

cat >"/etc/systemd/system/${SERVICE_NAME}.service" <<EOF
[Unit]
Description=VMess Domain Rotator updater
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
User=${RUN_USER}
Group=${RUN_GROUP}
WorkingDirectory=${APP_DIR}
ExecStart=/bin/bash ${APP_DIR}/scripts/run_update_and_commit.sh ${APP_DIR}/config.json
EOF

cat >"/etc/systemd/system/${SERVICE_NAME}.timer" <<EOF
[Unit]
Description=Run VMess Domain Rotator every ${INTERVAL}

[Timer]
OnBootSec=2min
OnUnitActiveSec=${INTERVAL}
AccuracySec=30s
Unit=${SERVICE_NAME}.service
Persistent=true

[Install]
WantedBy=timers.target
EOF

systemctl daemon-reload
systemctl enable --now "${SERVICE_NAME}.timer"
systemctl start "${SERVICE_NAME}.service"

echo "Installed successfully."
echo "Deploy mode: ${DEPLOY_MODE}"
echo "App dir: ${APP_DIR}"
echo "Service: ${SERVICE_NAME}.service"
echo "Timer: ${SERVICE_NAME}.timer"
echo "Check status: systemctl status ${SERVICE_NAME}.timer"
echo "View logs: journalctl -u ${SERVICE_NAME}.service -n 50 --no-pager"