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

#===============================================================================
# login-info 安装脚本
# 作用:
#   1) 安装命令: /usr/local/bin/login-info
#   2) 写入登录启动脚本: /etc/profile.d/smy-login-info.sh
#
# 用法:
#   sudo bash login-info/install_login-info.sh
#   sudo bash login-info/install_login-info.sh --mode full
#   sudo bash login-info/install_login-info.sh --all
#
# 禁用(用户级):
#   touch ~/.login-info-disable
#   或: export LOGIN_INFO_DISABLE=1
#
# 禁用(全局):
#   sudo mkdir -p /etc/login-info
#   sudo touch /etc/login-info/disable
#===============================================================================

log() { printf '[login-info-安装] %s\n' "$*" >&2; }
fail() { log "错误: $*"; exit 1; }

require_root() {
    if [ "${EUID:-$(id -u)}" -ne 0 ]; then
        fail "请使用 root 权限运行 (sudo bash login-info/install_login-info.sh)"
    fi
}

main() {
    local default_mode="summary"
    local ssh_only="1"

    while [ $# -gt 0 ]; do
        case "$1" in
            --mode)
                shift
                [ $# -gt 0 ] || fail "--mode 需要参数: summary|full"
                default_mode=$1
                ;;
            --mode=*)
                default_mode=${1#*=}
                ;;
            --ssh-only)
                ssh_only="1"
                ;;
            --all)
                ssh_only="0"
                ;;
            -h|--help)
                cat <<'EOF'
用法:
  sudo bash login-info/install_login-info.sh [--mode summary|full] [--ssh-only|--all]
EOF
                return 0
                ;;
            *)
                fail "未知参数: $1"
                ;;
        esac
        shift
    done

    case "$default_mode" in
        summary|full) ;;
        *) fail "--mode 仅支持: summary|full" ;;
    esac

    require_root

    local script_dir script_src bin_path profile_hook
    script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
    script_src="${script_dir}/login-info.sh"
    bin_path="/usr/local/bin/login-info"
    profile_hook="/etc/profile.d/smy-login-info.sh"

    [ -f "$script_src" ] || fail "未找到脚本: $script_src"

    mkdir -p "$(dirname "$bin_path")"
    mkdir -p "$(dirname "$profile_hook")"

    log "安装命令到: $bin_path"
    if command -v install >/dev/null 2>&1; then
        install -m 0755 "$script_src" "$bin_path"
    else
        cp "$script_src" "$bin_path"
        chmod 0755 "$bin_path"
    fi

    log "写入登录启动脚本: $profile_hook"
    cat >"$profile_hook" <<EOF
# /etc/profile.d/smy-login-info.sh
# 由 login-info 安装脚本生成：SSH 登录后自动展示服务器信息
#
# 禁用：
#   - export LOGIN_INFO_DISABLE=1
#   - touch ~/.login-info-disable
#   - touch /etc/login-info/disable
#
# 覆盖默认行为：
#   - export LOGIN_INFO_MODE=summary|full
#   - export LOGIN_INFO_SSH_ONLY=1|0

# 仅在交互式且有 TTY 时运行（避免 scp/sftp 等非交互场景）
case "\$-" in
    *i*) ;;
    *) return 0 2>/dev/null || exit 0 ;;
esac

if ! [ -t 1 ]; then
    return 0 2>/dev/null || exit 0
fi

# 避免重复输出
if [ -n "\${LOGIN_INFO_SHOWN:-}" ]; then
    return 0 2>/dev/null || exit 0
fi

# 禁用开关
if [ -n "\${LOGIN_INFO_DISABLE:-}" ]; then
    return 0 2>/dev/null || exit 0
fi

if [ -f "/etc/login-info/disable" ]; then
    return 0 2>/dev/null || exit 0
fi

if [ -n "\${HOME:-}" ] && [ -f "\${HOME}/.login-info-disable" ]; then
    return 0 2>/dev/null || exit 0
fi

# SSH-only（默认开启，可通过环境变量覆盖）
__smy_login_info_ssh_only="\${LOGIN_INFO_SSH_ONLY:-${ssh_only}}"
if [ "\$__smy_login_info_ssh_only" = "1" ]; then
    if [ -z "\${SSH_CONNECTION:-}" ] && [ -z "\${SSH_TTY:-}" ]; then
        return 0 2>/dev/null || exit 0
    fi
fi

export LOGIN_INFO_SHOWN=1

__smy_login_info_mode="\${LOGIN_INFO_MODE:-${default_mode}}"
if command -v login-info >/dev/null 2>&1; then
    if [ "\$__smy_login_info_mode" = "full" ]; then
        login-info --full || true
    else
        login-info --summary || true
    fi
fi
EOF

    chmod 0644 "$profile_hook"

    log "安装完成"
    log "提示: 重新登录 SSH 即可看到信息；或手动运行: login-info --full"
}

main "$@"