package main

import (
	"encoding/json"
	"fmt"
	"net"
	"net/http"
	"os/exec"
	"strings"
)

// 执行shell命令，返回完整输出
func runShell(cmdStr string) (string, error) {
	args := strings.Fields(cmdStr)
	cmd := exec.Command(args[0], args[1:]...)
	out, err := cmd.CombinedOutput()
	return string(out), err
}

// 统一返回JSON结构
type Resp struct {
	Code int    `json:"code"`
	Msg  string `json:"msg"`
	Err  string `json:"err,omitempty"`
}

// 单节点安装接口
func singleInstallHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	r.ParseForm()

	host := r.Form.Get("host")
	sshPort := r.Form.Get("ssh_port")
	user := r.Form.Get("user")
	pwd := r.Form.Get("pwd")

	cmd := fmt.Sprintf("./install_node_exporter.sh --cli --action single-install --host %s --ssh-port %s --user %s --pwd %s", host, sshPort, user, pwd)
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// 单节点卸载接口
func singleUninstallHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	r.ParseForm()

	host := r.Form.Get("host")
	sshPort := r.Form.Get("ssh_port")
	user := r.Form.Get("user")
	pwd := r.Form.Get("pwd")

	cmd := fmt.Sprintf("./install_node_exporter.sh --cli --action single-uninstall --host %s --ssh-port %s --user %s --pwd %s", host, sshPort, user, pwd)
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// 批量安装接口
func batchInstallHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	cmd := "./install_node_exporter.sh --cli --action batch-install"
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// 批量卸载接口
func batchUninstallHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	cmd := "./install_node_exporter.sh --cli --action batch-uninstall"
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// 获取hosts主机列表
func getHostsHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	cmd := "./install_node_exporter.sh --cli --action get-hosts"
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// 重启Prometheus
func restartPromHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	cmd := "./install_node_exporter.sh --cli --action restart-prom"
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

// SSH诊断接口
func diagSshHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	r.ParseForm()

	host := r.Form.Get("host")
	sshPort := r.Form.Get("ssh_port")
	user := r.Form.Get("user")
	pwd := r.Form.Get("pwd")

	cmd := fmt.Sprintf("./install_node_exporter.sh --cli --action diag-ssh --host %s --ssh-port %s --user %s --pwd %s", host, sshPort, user, pwd)
	output, err := runShell(cmd)

	resp := Resp{Code: 0, Msg: output}
	if err != nil {
		resp.Code = 1
		resp.Err = err.Error()
	}
	json.NewEncoder(w).Encode(resp)
}

func main() {
	// API路由
	http.HandleFunc("/api/single/install", singleInstallHandler)
	http.HandleFunc("/api/single/uninstall", singleUninstallHandler)
	http.HandleFunc("/api/batch/install", batchInstallHandler)
	http.HandleFunc("/api/batch/uninstall", batchUninstallHandler)
	http.HandleFunc("/api/hosts/list", getHostsHandler)
	http.HandleFunc("/api/prom/restart", restartPromHandler)
	http.HandleFunc("/api/ssh/diag", diagSshHandler)

	// 静态前端页面
	http.Handle("/", http.FileServer(http.Dir("./static")))

	localIP := getLocalIP()
	fmt.Printf("Web管理面板启动成功，监听 0.0.0.0:808\n访问地址：http://%s:808\n", localIP)
	err := http.ListenAndServe("0.0.0.0:808", nil)
	if err != nil {
		fmt.Println("服务启动失败:", err)
	}
}

// 获取本机内网IP（简易工具）
func getLocalIP() string {
	addrs, err := net.InterfaceAddrs()
	if err != nil {
		return "服务器IP"
	}
	for _, addr := range addrs {
		if ipNet, ok := addr.(*net.IPNet); ok && !ipNet.IP.IsLoopback() {
			if ipNet.IP.To4() != nil {
				return ipNet.IP.String()
			}
		}
	}
	return "服务器IP"
}