#!/bin/bash

# Ubuntu/Debian/CentOS/RHEL系统优化与Docker准备脚本
# 精简版 - 不备份文件，适合小存储空间VPS

# 颜色定义
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
PURPLE='\033[0;35m'
CYAN='\033[0;36m'
NC='\033[0m'

# 日志文件
LOG_FILE="/tmp/system_optimization.log"

# 错误处理函数
handle_error() {
    echo -e "${RED}❌ 错误: $1${NC}"
    echo "详细日志请查看: $LOG_FILE"
    exit 1
}

# 日志记录函数
log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" >> "$LOG_FILE"
}

# 检查命令是否存在
check_command() {
    if ! command -v "$1" &> /dev/null; then
        return 1
    fi
    return 0
}

# 检测系统类型
detect_os() {
    echo -e "${BLUE}🔍 检测操作系统...${NC}"
    
    if [ -f /etc/os-release ]; then
        . /etc/os-release
        OS_NAME=$ID
        OS_VERSION=$VERSION_ID
        OS_PRETTY_NAME=$PRETTY_NAME
        
        echo -e "${GREEN}✅ 操作系统: $OS_PRETTY_NAME${NC}"
        echo -e "${GREEN}✅ 版本: $OS_VERSION${NC}"
        
        case $OS_NAME in
            ubuntu|debian)
                OS_TYPE="debian"
                PM="apt-get"
                UPDATE_CMD="apt-get update"
                UPGRADE_CMD="apt-get upgrade -y"
                INSTALL_CMD="apt-get install -y"
                AUTOREMOVE_CMD="apt-get autoremove -y"
                AUTOCLEAN_CMD="apt-get autoclean -y"
                ;;
            centos|rhel|fedora|rocky|almalinux)
                OS_TYPE="rhel"
                if check_command dnf; then
                    PM="dnf"
                    UPDATE_CMD="dnf update -y"
                    INSTALL_CMD="dnf install -y"
                else
                    PM="yum"
                    UPDATE_CMD="yum update -y"
                    INSTALL_CMD="yum install -y"
                fi
                AUTOREMOVE_CMD="$PM autoremove -y"
                AUTOCLEAN_CMD="$PM clean all"
                ;;
            *)
                handle_error "不支持的操作系统: $OS_NAME"
                ;;
        esac
    else
        handle_error "无法检测操作系统"
    fi
}

# 检查系统架构
check_architecture() {
    echo -e "${BLUE}🔍 检查系统架构...${NC}"
    ARCH=$(uname -m)
    case $ARCH in
        x86_64)
            echo -e "${GREEN}✅ 系统架构: AMD64${NC}"
            ;;
        aarch64)
            echo -e "${GREEN}✅ 系统架构: ARM64${NC}"
            ;;
        *)
            echo -e "${YELLOW}⚠️  检测到非常见架构: $ARCH${NC}"
            ;;
    esac
}

# 清理系统缓存和旧包
clean_system() {
    echo -e "${BLUE}🧹 清理系统缓存和旧包...${NC}"
    
    if [ "$OS_TYPE" = "debian" ]; then
        # 清理apt缓存
        apt-get clean >> "$LOG_FILE" 2>&1 || echo -e "${YELLOW}⚠️  apt清理缓存失败${NC}"
        apt-get autoremove -y >> "$LOG_FILE" 2>&1 || echo -e "${YELLOW}⚠️  apt自动移除失败${NC}"
        
        # 清理旧内核（仅保留最新1个以节省空间）
        if check_command dpkg; then
            OLD_KERNELS=$(dpkg -l | grep -E "linux-image-[0-9]" | grep -v $(uname -r | sed 's/-generic//') | awk '{print $2}')
            if [ -n "$OLD_KERNELS" ]; then
                echo -e "${BLUE}移除旧内核: $OLD_KERNELS${NC}"
                apt-get remove -y $OLD_KERNELS >> "$LOG_FILE" 2>&1 || true
            fi
        fi
    elif [ "$OS_TYPE" = "rhel" ]; then
        # 清理yum/dnf缓存
        $PM clean all >> "$LOG_FILE" 2>&1 || echo -e "${YELLOW}⚠️  $PM清理缓存失败${NC}"
        
        # 清理旧内核（仅保留最新1个）
        if [ "$PM" = "yum" ]; then
            package-cleanup --oldkernels --count=1 -y >> "$LOG_FILE" 2>&1 || true
        elif [ "$PM" = "dnf" ]; then
            dnf remove --oldinstallonly --setopt installonly_limit=1 -y >> "$LOG_FILE" 2>&1 || true
        fi
    fi
    
    # 清理临时文件（不清理太多避免影响运行）
    rm -rf /tmp/*.deb /tmp/*.rpm /var/tmp/*.deb /var/tmp/*.rpm >> "$LOG_FILE" 2>&1 || true
    
    # 清理日志文件（保留最近7天）
    find /var/log -name "*.log" -type f -mtime +7 -delete 2>/dev/null || true
    find /var/log -name "*.gz" -type f -delete 2>/dev/null || true
    
    echo -e "${GREEN}✅ 系统清理完成${NC}"
}

# 更新系统包管理器
update_package_manager() {
    echo -e "${BLUE}🔄 更新包管理器...${NC}"
    
    if [ "$OS_TYPE" = "debian" ]; then
        # 更新apt源
        if ! $UPDATE_CMD >> "$LOG_FILE" 2>&1; then
            echo -e "${YELLOW}⚠️  包管理器更新失败，尝试修复...${NC}"
            
            # 修复可能的损坏
            dpkg --configure -a >> "$LOG_FILE" 2>&1 || true
            apt-get install -f -y >> "$LOG_FILE" 2>&1 || true
        fi
    elif [ "$OS_TYPE" = "rhel" ]; then
        if ! $UPDATE_CMD >> "$LOG_FILE" 2>&1; then
            echo -e "${YELLOW}⚠️  包管理器更新失败，尝试修复...${NC}"
            
            # 修复可能的损坏
            rpm --rebuilddb >> "$LOG_FILE" 2>&1 || true
            $PM clean all >> "$LOG_FILE" 2>&1 || true
        fi
    fi
    
    echo -e "${GREEN}✅ 包管理器更新完成${NC}"
}

# 安装基础依赖（精简版）
install_basic_dependencies() {
    echo -e "${BLUE}📦 安装基础依赖包...${NC}"
    
    local base_packages=()
    
    if [ "$OS_TYPE" = "debian" ]; then
        base_packages=(
            "curl" "wget" "gnupg" "lsb-release" "apt-transport-https" 
            "ca-certificates" "software-properties-common"
            "net-tools" "dnsutils" "iputils-ping" "sudo" "bc"
        )
    elif [ "$OS_TYPE" = "rhel" ]; then
        base_packages=(
            "curl" "wget" "gnupg" "redhat-lsb-core" "yum-utils" "epel-release"
            "ca-certificates" "device-mapper-persistent-data" "lvm2"
            "net-tools" "bind-utils" "iputils" "sudo" "bc"
        )
    fi
    
    for package in "${base_packages[@]}"; do
        echo -e "${BLUE}安装 $package...${NC}"
        if ! $INSTALL_CMD "$package" >> "$LOG_FILE" 2>&1; then
            echo -e "${YELLOW}⚠️  $package 安装失败，跳过...${NC}"
        fi
    done
    
    echo -e "${GREEN}✅ 基础依赖安装完成${NC}"
}

# 配置系统优化参数
configure_system_optimization() {
    echo -e "${BLUE}⚙️  配置系统优化参数...${NC}"
    
    # 优化内核参数 - 直接修改，不备份
    if ! grep -q "系统优化配置" /etc/sysctl.conf; then
        cat >> /etc/sysctl.conf << EOF

# 系统优化配置 - 添加于 $(date)
# 网络优化
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 16384 16777216
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_tw_reuse = 1

# 内存优化
vm.swappiness = 10
vm.dirty_ratio = 15
vm.dirty_background_ratio = 5

# 文件系统优化
fs.file-max = 65536
EOF
    fi
    
    # 应用配置
    sysctl -p >> "$LOG_FILE" 2>&1 || echo -e "${YELLOW}⚠️  sysctl配置应用失败${NC}"
    
    # 配置文件描述符限制
    if ! grep -q "文件描述符限制" /etc/security/limits.conf; then
        cat >> /etc/security/limits.conf << EOF

# 文件描述符限制 - 添加于 $(date)
* soft nofile 65536
* hard nofile 65536
root soft nofile 65536
root hard nofile 65536
EOF
    fi
    
    echo -e "${GREEN}✅ 系统优化配置完成${NC}"
}

# 配置DNS优化
configure_dns() {
    echo -e "${BLUE}🌐 配置DNS优化...${NC}"
    
    # 直接配置，不备份
    cat > /etc/resolv.conf << EOF
# DNS配置 - 优化于 $(date)
nameserver 223.5.5.5
nameserver 119.29.29.29
nameserver 8.8.8.8
nameserver 1.1.1.1
options timeout:2 attempts:3 rotate
EOF
    
    # 防止NetworkManager覆盖配置
    if [ -f /etc/NetworkManager/NetworkManager.conf ]; then
        sed -i 's/^dns=.*/dns=none/' /etc/NetworkManager/NetworkManager.conf 2>/dev/null || true
    fi
    
    echo -e "${GREEN}✅ DNS优化配置完成${NC}"
}

# 配置Docker安装环境
configure_docker_environment() {
    echo -e "${BLUE}🐳 配置Docker安装环境...${NC}"
    
    if [ "$OS_TYPE" = "debian" ]; then
        # 添加Docker官方GPG密钥
        curl -fsSL https://download.docker.com/linux/$OS_NAME/gpg | gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg >> "$LOG_FILE" 2>&1 || {
            echo -e "${YELLOW}⚠️  Docker GPG密钥添加失败，使用备用方案${NC}"
            curl -fsSL https://download.docker.com/linux/$OS_NAME/gpg | apt-key add - >> "$LOG_FILE" 2>&1 || true
        }
        
        # 添加Docker仓库
        echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/$OS_NAME $(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
        
        # 更新包列表
        $UPDATE_CMD >> "$LOG_FILE" 2>&1 || echo -e "${YELLOW}⚠️  更新包列表失败${NC}"
        
    elif [ "$OS_TYPE" = "rhel" ]; then
        # 添加Docker仓库
        $INSTALL_CMD yum-utils >> "$LOG_FILE" 2>&1 || true
        yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo >> "$LOG_FILE" 2>&1 || {
            echo -e "${YELLOW}⚠️  Docker仓库添加失败，使用官方仓库${NC}"
        }
        
        # 更新包列表
        $UPDATE_CMD >> "$LOG_FILE" 2>&1 || true
    fi
    
    echo -e "${GREEN}✅ Docker环境配置完成${NC}"
}

# 安装Docker
install_docker() {
    echo -e "${BLUE}🐳 安装Docker...${NC}"
    
    # 检查是否已安装Docker
    if check_command docker; then
        echo -e "${YELLOW}⚠️  Docker已安装，跳过安装${NC}"
        return 0
    fi
    
    if [ "$OS_TYPE" = "debian" ]; then
        $INSTALL_CMD docker-ce docker-ce-cli containerd.io docker-compose-plugin >> "$LOG_FILE" 2>&1 || {
            echo -e "${YELLOW}⚠️  Docker安装失败，尝试替代方案${NC}"
            # 尝试安装docker.io
            $INSTALL_CMD docker.io containerd runc >> "$LOG_FILE" 2>&1 || {
                echo -e "${RED}❌ Docker安装完全失败${NC}"
                return 1
            }
        }
    elif [ "$OS_TYPE" = "rhel" ]; then
        $INSTALL_CMD docker-ce docker-ce-cli containerd.io docker-compose-plugin >> "$LOG_FILE" 2>&1 || {
            echo -e "${YELLOW}⚠️  Docker安装失败，尝试替代方案${NC}"
            $INSTALL_CMD docker >> "$LOG_FILE" 2>&1 || {
                echo -e "${RED}❌ Docker安装完全失败${NC}"
                return 1
            }
        }
    fi
    
    # 启动Docker服务
    systemctl enable docker >> "$LOG_FILE" 2>&1 || true
    systemctl start docker >> "$LOG_FILE" 2>&1 || true
    
    # 验证安装
    if docker --version >> "$LOG_FILE" 2>&1; then
        echo -e "${GREEN}✅ Docker安装成功: $(docker --version)${NC}"
        
        # 配置用户组
        usermod -aG docker $USER 2>/dev/null || true
        echo -e "${GREEN}✅ 已将当前用户添加到docker组${NC}"
    else
        echo -e "${RED}❌ Docker安装验证失败${NC}"
        return 1
    fi
}

# 安装Docker Compose
install_docker_compose() {
    echo -e "${BLUE}🐳 安装Docker Compose...${NC}"
    
    # 检查是否已安装
    if check_command docker-compose; then
        echo -e "${YELLOW}⚠️  Docker Compose已安装，跳过${NC}"
        return 0
    fi
    
    # 安装最新版本
    COMPOSE_VERSION=$(curl -s https://api.github.com/repos/docker/compose/releases/latest | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/')
    
    if [ -z "$COMPOSE_VERSION" ]; then
        COMPOSE_VERSION="v2.24.0"  # 备用版本
    fi
    
    curl -L "https://github.com/docker/compose/releases/download/${COMPOSE_VERSION}/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose >> "$LOG_FILE" 2>&1
    
    if [ $? -eq 0 ]; then
        chmod +x /usr/local/bin/docker-compose
        ln -sf /usr/local/bin/docker-compose /usr/bin/docker-compose 2>/dev/null || true
        
        echo -e "${GREEN}✅ Docker Compose安装成功: ${COMPOSE_VERSION}${NC}"
    else
        echo -e "${YELLOW}⚠️  Docker Compose安装失败，跳过${NC}"
    fi
}

# 验证安装结果
verify_installation() {
    echo -e "${BLUE}🔍 验证安装结果...${NC}"
    
    echo -e "${CYAN}系统信息:${NC}"
    echo -e "  OS: $OS_PRETTY_NAME"
    echo -e "  内核: $(uname -r)"
    echo -e "  架构: $(uname -m)"
    
    echo -e "${CYAN}服务状态:${NC}"
    if systemctl is-active docker >/dev/null 2>&1; then
        echo -e "  Docker: ${GREEN}运行中${NC}"
    else
        echo -e "  Docker: ${RED}未运行${NC}"
    fi
    
    echo -e "${CYAN}版本信息:${NC}"
    if check_command docker; then
        echo -e "  Docker: $(docker --version 2>/dev/null | cut -d' ' -f3 | tr -d ',')"
    else
        echo -e "  Docker: ${RED}未安装${NC}"
    fi
    
    if check_command docker-compose; then
        echo -e "  Docker Compose: $(docker-compose --version 2>/dev/null | cut -d' ' -f3 | tr -d ',')"
    else
        echo -e "  Docker Compose: ${YELLOW}未安装${NC}"
    fi
    
    # 显示磁盘空间
    echo -e "${CYAN}磁盘空间:${NC}"
    df -h / | tail -1 | awk '{print "  根分区: " $4 " 可用 / " $2 " 总大小"}'
    
    echo -e "${GREEN}✅ 验证完成${NC}"
}

# 显示使用说明
show_usage() {
    echo -e "${GREEN}系统优化与Docker准备脚本 (精简版)${NC}"
    echo -e "专为小存储空间VPS设计 - 不备份文件${NC}"
    echo -e ""
    echo -e "使用方法: $0 [选项]"
    echo -e ""
    echo -e "选项:"
    echo -e "  -h, --help     显示此帮助信息"
    echo -e "  -c, --clean    只执行清理操作"
    echo -e "  -o, --optimize 只执行系统优化"
    echo -e "  -d, --docker   只安装Docker"
    echo -e "  -a, --all      执行所有操作（默认）"
    echo -e ""
    echo -e "功能:"
    echo -e "  ✅ 系统检测"
    echo -e "  ✅ 深度清理（节省空间）"
    echo -e "  ✅ 依赖包安装"
    echo -e "  ✅ 系统优化配置"
    echo -e "  ✅ DNS优化"
    echo -e "  ✅ Docker环境准备"
    echo -e "  ✅ Docker安装与配置"
    echo -e ""
    echo -e "示例:"
    echo -e "  $0              # 执行所有操作"
    echo -e "  $0 --clean      # 只执行清理"
    echo -e "  $0 --docker     # 只安装Docker"
}

# 主函数
main() {
    # 创建日志文件
    > "$LOG_FILE"
    
    # 显示标题
    echo -e "${PURPLE}"
    echo "=================================================="
    echo "     🚀 系统优化与Docker准备脚本 (精简版)"
    echo "       专为小存储空间VPS设计"
    echo "=================================================="
    echo -e "${NC}"
    
    # 检查root权限
    if [ "$EUID" -ne 0 ]; then
        echo -e "${RED}❌ 请使用root权限运行此脚本${NC}"
        echo -e "使用: sudo $0"
        exit 1
    fi
    
    # 解析命令行参数
    case "${1:-}" in
        -h|--help)
            show_usage
            exit 0
            ;;
        -c|--clean)
            echo -e "${BLUE}执行清理操作...${NC}"
            detect_os
            clean_system
            exit 0
            ;;
        -o|--optimize)
            echo -e "${BLUE}执行系统优化...${NC}"
            detect_os
            configure_system_optimization
            configure_dns
            exit 0
            ;;
        -d|--docker)
            echo -e "${BLUE}安装Docker...${NC}"
            detect_os
            configure_docker_environment
            install_docker
            install_docker_compose
            verify_installation
            exit 0
            ;;
        -a|--all|*)
            # 执行所有操作
            ;;
    esac
    
    # 执行完整流程
    echo -e "${BLUE}开始系统优化与Docker准备...${NC}"
    
    detect_os
    check_architecture
    clean_system
    update_package_manager
    install_basic_dependencies
    configure_system_optimization
    configure_dns
    configure_docker_environment
    install_docker
    install_docker_compose
    
    echo -e "${GREEN}🎉 所有操作完成！${NC}"
    echo ""
    verify_installation
    echo ""
    echo -e "${YELLOW}💡 重要提示:${NC}"
    echo -e "  1. 建议重启系统以使所有配置生效"
    echo -e "  2. 当前用户已添加到docker组，重新登录后生效"
    echo -e "  3. 详细日志请查看: $LOG_FILE"
    echo -e "  4. 脚本已尽可能节省磁盘空间"
}

# 设置陷阱，确保脚本退出时重置颜色
trap 'echo -e "${NC}"' EXIT

# 运行主函数
main "$@"