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

REPO="${NG_REPO:-rogue/NexusGate}"
BRANCH="${NG_BRANCH:-main}"
# 自建 Gitea 分发基址（raw / release / archive 均由此拼装）
GIT_BASE="https://git.881218.xyz/${REPO}"
# Agent 实现：默认 go（静态二进制，节点机不再需要 Node.js）。
# NG_AGENT_IMPL=node 可回退到旧版 Node agent（agent/agent.js + nodejs 包）。
AGENT_IMPL="${NG_AGENT_IMPL:-go}"
# Go agent 二进制所在的 Gitea Release tag
AGENT_RELEASE="${NG_AGENT_RELEASE:-agent-v0.6.8}"
CONTROLLER=""
TOKEN=""

die() { printf '错误：%s\n' "$*" >&2; exit 1; }
info() { printf '\033[1;36m[NexusGate Agent]\033[0m %s\n' "$*"; }

# NG_LOCAL_SRC 指向本地源码目录时跳过远程下载（本地改动尚未 push 时用这个）
fetch() {
  if [[ -n "${NG_LOCAL_SRC:-}" ]]; then
    [[ -f "${NG_LOCAL_SRC}/$1" ]] || die "NG_LOCAL_SRC 目录缺少 $1"
    cp -a "${NG_LOCAL_SRC}/$1" "$2"
  else
    # 加时间戳破坏 raw 缓存，避免拉到旧版
    curl -fL --retry 3 "${GIT_BASE}/raw/branch/${BRANCH}/$1?t=$(date +%s)" -o "$2"
  fi
}

# uname -m → release 资产架构名（amd64/arm64）
agent_arch() {
  case "$(uname -m)" in
    x86_64|amd64) printf 'amd64' ;;
    aarch64|arm64) printf 'arm64' ;;
    *) return 1 ;;
  esac
}

# uname -m → Node 风格架构名（注册信息用，与旧版 process.arch 输出一致）
node_arch() {
  case "$(uname -m)" in
    x86_64|amd64) printf 'x64' ;;
    aarch64|arm64) printf 'arm64' ;;
    *) uname -m ;;
  esac
}

# 下载 Go agent 二进制到 $1（NG_LOCAL_SRC 时从 agent-go/ 取已构建产物）
fetch_agent_binary() {
  local arch out="$1"
  arch="$(agent_arch)" || die "不支持的架构：$(uname -m)"
  if [[ -n "${NG_LOCAL_SRC:-}" && -f "${NG_LOCAL_SRC}/agent-go/nexusgate-agent-linux-${arch}" ]]; then
    cp -a "${NG_LOCAL_SRC}/agent-go/nexusgate-agent-linux-${arch}" "$out"
  else
    curl -fL --retry 3 "${GIT_BASE}/releases/download/${AGENT_RELEASE}/nexusgate-agent-linux-${arch}" -o "$out"
  fi
  [[ -s "$out" ]] || die 'Agent 二进制下载不完整'
}

# 极简 JSON 字符串转义（注册请求拼 JSON 用）
json_escape() {
  local s="$1"
  s="${s//\\/\\\\}"
  s="${s//\"/\\\"}"
  printf '"%s"' "$s"
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --server) CONTROLLER="${2:-}"; shift 2 ;;
    --token) TOKEN="${2:-}"; shift 2 ;;
    --repo) REPO="${2:-}"; shift 2 ;;
    --branch) BRANCH="${2:-}"; shift 2 ;;
    *) die "未知参数：$1" ;;
  esac
done

[[ "${EUID}" -eq 0 ]] || die "请使用 root 运行"
[[ "$CONTROLLER" =~ ^https?:// ]] || die "--server 必须是完整的 HTTP(S) 地址"
[[ -n "$TOKEN" ]] || die "缺少 --token"
[[ "$AGENT_IMPL" == "go" || "$AGENT_IMPL" == "node" ]] || die "NG_AGENT_IMPL 只能是 go 或 node"
extra_pkgs=()
if [[ "$AGENT_IMPL" == "node" ]]; then
  # 仅回退到 Node 实现时才需要 nodejs
  extra_pkgs=(nodejs)
fi
if command -v apt-get >/dev/null; then
  export DEBIAN_FRONTEND=noninteractive
  apt-get update -qq && apt-get install -y -qq ca-certificates curl unzip openssl logrotate "${extra_pkgs[@]}"
elif command -v dnf >/dev/null; then
  dnf install -y ca-certificates curl unzip openssl logrotate "${extra_pkgs[@]}"
elif command -v apk >/dev/null; then
  apk add --no-cache bash ca-certificates curl unzip openrc openssl logrotate "${extra_pkgs[@]}"
else
  die "当前安装器支持 Debian/Ubuntu、RHEL 系和 Alpine"
fi
if [[ "$AGENT_IMPL" == "node" ]]; then
  node_major="$(node -p 'process.versions.node.split(`.`)[0]')"
  [[ "$node_major" -ge 18 ]] || die "需要 Node.js 18 或更高版本"
fi

tmp_dir="$(mktemp -d /tmp/nexusgate-agent.XXXXXX)"
trap 'rm -rf -- "$tmp_dir"' EXIT

install -d -m 0755 /opt/nexusgate-agent /usr/local/sbin
if [[ "$AGENT_IMPL" == "node" ]]; then
  fetch agent/agent.js /opt/nexusgate-agent/agent.js
  fetch agent/run.sh /opt/nexusgate-agent/run.sh
  chmod 0644 /opt/nexusgate-agent/agent.js
  chmod 0755 /opt/nexusgate-agent/run.sh
  rm -f -- /opt/nexusgate-agent/nexusgate-agent
else
  fetch_agent_binary "$tmp_dir/nexusgate-agent"
  install -m 0755 "$tmp_dir/nexusgate-agent" /opt/nexusgate-agent/nexusgate-agent
  # 从 Node 实现迁移过来的节点：清掉旧文件，避免新旧实现混淆
  rm -f -- /opt/nexusgate-agent/agent.js /opt/nexusgate-agent/run.sh
fi
fetch scripts/agent-update.sh /usr/local/sbin/ng-agent-update
fetch scripts/agent-uninstall.sh /usr/local/sbin/ng-agent-uninstall
fetch scripts/agent-doctor.sh /usr/local/sbin/ng-agent-doctor
fetch scripts/agent-cert.sh /usr/local/sbin/ng-agent-cert
fetch scripts/agent-singbox.sh /usr/local/sbin/ng-agent-singbox
fetch scripts/agent-logrotate.conf "$tmp_dir/logrotate.conf"
fetch scripts/agent-logrotate-setup.sh "$tmp_dir/logrotate-setup.sh"
cat > /usr/local/sbin/ng-agent <<'EOF'
#!/usr/bin/env bash
set -Eeuo pipefail
case "${1:-}" in
  update) exec ng-agent-update ;;
  uninstall) shift; exec ng-agent-uninstall "$@" ;;
  doctor|status) exec ng-agent-doctor ;;
  cert) shift; exec ng-agent-cert "$@" ;;
  engine) shift; exec ng-agent-singbox "$@" ;;
  *) printf 'NexusGate Agent: ng-agent doctor | ng-agent cert | ng-agent engine install | ng-agent update | ng-agent uninstall\n' ;;
esac
EOF
chmod 0755 /usr/local/sbin/ng-agent-update /usr/local/sbin/ng-agent-uninstall /usr/local/sbin/ng-agent-doctor /usr/local/sbin/ng-agent-cert /usr/local/sbin/ng-agent-singbox /usr/local/sbin/ng-agent
install -d -m 0700 /etc/nexusgate /etc/nexusgate/agent /etc/nexusgate/agent/resources /etc/nexusgate/sing-box
install -d -m 0750 /var/log/nexusgate
install -m 0644 "$tmp_dir/logrotate.conf" /etc/nexusgate/agent-logrotate.conf
install -m 0755 "$tmp_dir/logrotate-setup.sh" /usr/local/sbin/ng-agent-logrotate-setup
# sing-box 是唯一的入口引擎，安装时直接构建。
NG_REPO="$REPO" NG_BRANCH="$BRANCH" ng-agent-singbox install || die 'sing-box 引擎安装失败；修复后运行 ng-agent engine install'

info "向控制面注册"
enroll_json="$(printf '{"token":%s,"hostname":%s,"version":"0.6.8","system":{"platform":"linux","arch":%s}}' \
  "$(json_escape "$TOKEN")" "$(json_escape "$(hostname)")" "$(json_escape "$(node_arch)")")"
response="$(curl -fsS -H 'content-type: application/json' --data "$enroll_json" "${CONTROLLER%/}/api/agent/enroll")" || die "注册失败，请检查地址和令牌"
agent_key="$(printf '%s' "$response" | grep -o '"agentKey"[[:space:]]*:[[:space:]]*"[^"]*"' | head -n 1 | sed -E 's/^"agentKey"[[:space:]]*:[[:space:]]*"//; s/"$//')"
[[ -n "$agent_key" ]] || die "控制面返回无效"

{
  printf 'NG_CONTROLLER=%q\n' "${CONTROLLER%/}"
  printf 'NG_AGENT_KEY=%q\n' "$agent_key"
  printf 'NG_CONFIG_DIR=/etc/nexusgate/agent\n'
  printf 'NG_KEY_FILE=/etc/nexusgate/keys.json\n'
} > /etc/nexusgate/agent.env
chmod 0600 /etc/nexusgate/agent.env

if command -v systemctl >/dev/null && [[ -d /run/systemd/system ]]; then
  fetch systemd/nexusgate-agent.service /etc/systemd/system/nexusgate-agent.service
  fetch systemd/nexusgate-sing-box.service /etc/systemd/system/nexusgate-sing-box.service
  if [[ "$AGENT_IMPL" == "node" ]]; then
    # 仓库里的 unit 默认指向 Go 二进制；Node 回退改为经 run.sh 启动
    sed -i 's|^ExecStart=.*|ExecStart=/opt/nexusgate-agent/run.sh|' /etc/systemd/system/nexusgate-agent.service
  fi
  systemctl daemon-reload
  systemctl enable nexusgate-sing-box.service nexusgate-agent.service
  rm -f -- /etc/nexusgate/last-heartbeat.json
  systemctl restart nexusgate-sing-box.service
  systemctl restart nexusgate-agent.service
  service_manager="systemd"
elif command -v rc-service >/dev/null; then
  install -d -m 0755 /etc/init.d
  fetch openrc/nexusgate-agent /etc/init.d/nexusgate-agent
  fetch openrc/nexusgate-sing-box /etc/init.d/nexusgate-sing-box
  chmod 0755 /etc/init.d/nexusgate-agent /etc/init.d/nexusgate-sing-box
  if [[ "$AGENT_IMPL" == "node" ]]; then
    # 仓库里的 OpenRC 服务默认指向 Go 二进制；Node 回退改为经 run.sh 启动
    sed -i 's|^command=.*|command="/opt/nexusgate-agent/run.sh"|' /etc/init.d/nexusgate-agent
  fi
  rc-update add nexusgate-sing-box default >/dev/null
  rc-update add nexusgate-agent default >/dev/null
  # Alpine runs the dedicated hourly task through BusyBox crond.
  if [[ -e /etc/init.d/crond ]]; then
    rc-update add crond default >/dev/null 2>&1 || true
    rc-service crond start >/dev/null 2>&1 || true
  fi
  rc-service nexusgate-sing-box restart
  rm -f -- /etc/nexusgate/last-heartbeat.json
  rc-service nexusgate-agent restart
  service_manager="OpenRC"
else
  die "未检测到 systemd 或 OpenRC"
fi
ng-agent-logrotate-setup
for _ in {1..35}; do
  [[ -s /etc/nexusgate/last-heartbeat.json ]] && break
  sleep 1
done
if [[ ! -s /etc/nexusgate/last-heartbeat.json ]]; then
  if [[ "$service_manager" == systemd ]]; then journalctl -u nexusgate-agent.service -n 35 --no-pager || true; fi
  die 'Agent 注册成功但没有向控制面上报心跳；运行 ng-agent doctor 排查后再重试'
fi
printf '\n\033[1;32mAgent 安装、注册和首次心跳完成（%s）。\033[0m\n' "$service_manager"
printf '后续更新 Agent：ng-agent-update\n'
printf '卸载 Agent：ng-agent uninstall\n'
printf '检查 Agent 与 sing-box：ng-agent doctor\n'
if [[ "$service_manager" == systemd ]] && ! systemctl is-active --quiet nexusgate-agent.service; then
  journalctl -u nexusgate-agent.service -n 35 --no-pager || true
  die 'Agent 注册已完成，但服务没有运行；请执行 ng-agent doctor 检查原因'
fi