#!/bin/bash
set -euo pipefail

# 全局变量
LOG_FILE="/var/log/node_exporter_$(date +%Y%m%d%H%M%S).log"
NODE_EXPORTER_VERSION="1.8.2"
PRIMARY_DOWNLOAD_URL="http://10.101.0.51:5588/node-exporter/node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz"
BACKUP_DOWNLOAD_URL="https://github.com/prometheus/node_exporter/releases/download/v${NODE_EXPORTER_VERSION}/node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz"
LOCAL_PACKAGE_PATH="/opt/node_exporter.tar.gz"

# 颜色定义
GREEN='\033[1;32m'
RED='\033[1;31m'
NC='\033[0m' # 重置颜色

# 日志函数 - 记录所有操作到日志
log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >> "$LOG_FILE"
}

# 步骤提示 - 绿色输出到控制台并记录日志
step() {
    local msg="==> $1"
    echo -e "${GREEN}$msg${NC}"
    log "$msg"
}

# 错误提示 - 红色输出到控制台并记录日志
error() {
    local msg="错误: $1"
    echo -e "${RED}$msg${NC}"
    log "$msg"
    exit 1
}

# 执行命令并屏蔽输出
run_cmd() {
    step "执行: $1"
    eval "$1" &>> "$LOG_FILE" || {
        error "命令执行失败: $1"
    }
}

# 测试网络连通性
test_network_connectivity() {
    local url=$1
    step "测试网络连通性: $url"
    if curl -fsSLI --connect-timeout 10 "$url" &>> "$LOG_FILE"; then
        return 0
    else
        return 1
    fi
}

# 下载文件
download_file() {
    local url=$1
    local dest=$2
    step "下载文件: $url 到 $dest"
    if wget -qO "$dest" "$url" &>> "$LOG_FILE"; then
        return 0
    else
        return 1
    fi
}

# 安装 node_exporter
install_node_exporter() {
    step "开始安装 node_exporter ${NODE_EXPORTER_VERSION}"
    
    # 切换到 /opt 目录
    run_cmd "cd /opt"
    
    # 检查本地是否存在安装包
    if [[ -f "$LOCAL_PACKAGE_PATH" ]]; then
        step "发现本地安装包: $LOCAL_PACKAGE_PATH"
        DOWNLOAD_URL="$LOCAL_PACKAGE_PATH"
    else
        # 测试主要下载地址的连通性
        if test_network_connectivity "$PRIMARY_DOWNLOAD_URL"; then
            DOWNLOAD_URL="$PRIMARY_DOWNLOAD_URL"
        elif test_network_connectivity "$BACKUP_DOWNLOAD_URL"; then
            DOWNLOAD_URL="$BACKUP_DOWNLOAD_URL"
        else
            error "无法连接到任何下载地址"
        fi
        
        # 下载 node_exporter
        download_file "$DOWNLOAD_URL" "node_exporter.tar.gz"
    fi
    
    # 解压 tar 包
    run_cmd "tar -zxvf node_exporter.tar.gz"
    
    # 移动文件夹
    run_cmd "mv node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64/ ./node_exporter"
    
    # 进入 node_exporter 目录
    run_cmd "cd node_exporter/"
    
    # 创建 bin 目录并移动二进制文件
    run_cmd "mkdir bin"
    run_cmd "mv node_exporter bin/"
    
    # 配置 systemd 服务
    cat > /lib/systemd/system/node_exporter.service <<EOF
[Unit]
Description=node_exporter
Documentation=https://prometheus.io/docs/guides/node-exporter/
After=network.target

[Service]
User=root
Group=root
ExecStart=/opt/node_exporter/bin/node_exporter --web.listen-address=:10086
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF
    
    # 重新加载 systemd 配置
    run_cmd "systemctl daemon-reload"
    
    # 启用并启动 node_exporter 服务
    run_cmd "systemctl enable node_exporter"
    run_cmd "systemctl restart node_exporter"
    
    # 检查服务状态
    run_cmd "systemctl status node_exporter"
    
    # 验证安装
    run_cmd "curl -I http://127.000.1:10086/metrics"
    
    step "node_exporter 安装成功"
}

# 卸载 node_exporter
uninstall_node_exporter() {
    step "开始卸载 node_exporter"
    
    # 停止并禁用服务
    run_cmd "systemctl stop node_exporter"
    run_cmd "systemctl disable node_exporter"
    
    # 删除 systemd 服务文件
    run_cmd "rm -f /lib/systemd/system/node_exporter.service"
    
    # 重新加载 systemd 配置
    run_cmd "systemctl daemon-reload"
    
    # 删除 node_exporter 目录和文件
    run_cmd "rm -rf /opt/node_exporter"
    run_cmd "rm -f /opt/node_exporter.tar.gz"
    
    step "node_exporter 卸载完成"
}

# 参数解析
if [[ $# -ne 1 ]]; then
    error "请使用 --install 或 --uninstall"
fi

ACTION=$1
case "$ACTION" in
    "--install")
        install_node_exporter
        ;;
    "--uninstall")
        uninstall_node_exporter
        ;;
    *)
        error "无效的参数，请使用 --install 或 --uninstall"
        ;;
esac

step "操作完成，日志路径: $LOG_FILE"