package main

import (
	"context"
	"coredump-tools/types"
	"crypto/rand"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"math/big"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"golang.org/x/crypto/ssh/terminal"
	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/kubernetes/scheme"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/tools/remotecommand"
)

var configs []types.Coredump_config

func terminalSize() (width, height int, err error) {
	file, err := os.OpenFile("/dev/tty", os.O_WRONLY, 0)
	if err != nil {
		return 0, 0, err
	}
	defer file.Close()

	width, height, err = terminal.GetSize(int(file.Fd()))
	if err != nil {
		return 0, 0, err
	}
	return width, height, nil
}
func debug(config types.Coredump_config, command string) error {
	// 使用kubectl命令执行debug操作
	if config.Image_name != "" {
		// // 定义要运行的 kubectl 命令
		// command := "kubectl get nodes -o jsonpath='{range .items[*]}{.metadata.name} {end}'"

		// // 在 shell 中运行 kubectl 命令并读取输出
		// cmd := exec.Command("bash", "-c", command)
		// output, err := cmd.Output()
		// if err != nil {
		// 	return err
		// }

		// // 将输出字符串按空格拆分为字符串切片
		// nodes := strings.Split(strings.TrimSpace(string(output)), " ")
		// if len(nodes) == 0 {
		// 	return errors.New("the node list is empty")
		// }
		// if command == "gdb" {
		// 	chmod := "cd" + filepath.Dir(config.Process_exe_path)
		// 	cmd := exec.Command("kubectl", "debug", "node/"+nodes[0], "-it", "--image="+config.Image_id, "--image-pull-policy=Never", "--", "gdb", config.Process_exe_path, "/host"+config.Storage, "-ex", chmod)
		// 	cmd.Stdin = os.Stdin
		// 	cmd.Stdout = os.Stdout
		// 	cmd.Stderr = os.Stderr
		// 	fmt.Println(cmd.String())
		// 	if err := cmd.Start(); err != nil {
		// 		return err
		// 	}
		// 	err := cmd.Wait()
		// 	if err != nil {
		// 		return err
		// 	}
		// } else {
		// 	cmd := exec.Command("kubectl", "debug", "node/"+config.Hostname, "-it", "--image="+config.Image_id, "--image-pull-policy=Never", "--", command)
		// 	cmd.Stdin = os.Stdin
		// 	cmd.Stdout = os.Stdout
		// 	cmd.Stderr = os.Stderr
		// 	fmt.Println(cmd.String())
		// 	fmt.Println("exe=", config.Process_exe_path, "coredump=/host", config.Storage)
		// 	if err := cmd.Start(); err != nil {
		// 		return err
		// 	}
		// 	err := cmd.Wait()
		// 	if err != nil {
		// 		return err
		// 	}
		// }
		kubeconfig := os.Getenv("KUBECONFIG")
		if kubeconfig == "" {
			kubeconfig = os.Getenv("HOME") + "/.kube/config"
		}

		// Creates the kubernetes client using the specified kubeconfig
		conf, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
		if err != nil {
			return err
		}

		clientset, err := kubernetes.NewForConfig(conf)
		if err != nil {
			return err
		}
		podName, err := debugInpod(conf, clientset, config, command)
		if err != nil {
			fmt.Println(err)
		}
		// Delete the Pod
		fmt.Printf("Deleting Pod %q...\n", podName)
		err = clientset.CoreV1().Pods("default").Delete(context.Background(), podName, metav1.DeleteOptions{})
		if err != nil {
			return err
		}
		fmt.Printf("Deleted Pod %q.\n", podName)
		return nil
	} else { // 使用gdb命令进行命令行交互分析
		cmd := exec.Command("gdb", config.Process_exe_path, config.Storage)
		cmd.Stdin = os.Stdin
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr
		fmt.Println(cmd.String())
		if err := cmd.Run(); err != nil {
			return err
		}
	}
	return nil
}
func generateRandomString(length int) (string, error) {
	const charset = "abcdefghijklmnopqrstuvwxyz0123456789"
	bytes := make([]byte, length)
	max := big.NewInt(int64(len(charset)))
	for i := 0; i < length; i++ {
		n, err := rand.Int(rand.Reader, max)
		if err != nil {
			return "", err
		}
		bytes[i] = charset[n.Int64()]
	}
	return string(bytes), nil
}
func debugInpod(conf *rest.Config, clientset *kubernetes.Clientset, config types.Coredump_config, command string) (string, error) {
	// Define the Pod object
	randword, err := generateRandomString(5)
	if err != nil {
		return "", err
	}
	podName := fmt.Sprintf("node-debug-%s-%d", randword, time.Now().Unix())
	containerName := "debug"
	pod := &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Name:      podName,
			Namespace: "default",
		},
		Spec: v1.PodSpec{
			Containers: []v1.Container{
				{
					Name:            "debug",
					Image:           config.Image_name,
					ImagePullPolicy: "IfNotPresent",
					Command: []string{
						"tail",
						"-f",
					},
					VolumeMounts: []v1.VolumeMount{
						{
							Name:      "host-dir",
							MountPath: "/host",
						},
					},
					SecurityContext: &v1.SecurityContext{
						Privileged: &[]bool{true}[0],
					},
				},
			},
			Volumes: []v1.Volume{
				{
					Name: "host-dir",
					VolumeSource: v1.VolumeSource{
						HostPath: &v1.HostPathVolumeSource{
							Path: "/",
						},
					},
				},
			},
			RestartPolicy: v1.RestartPolicyNever,
		},
	}

	// Create the Pod
	fmt.Println("Creating Pod...")
	fmt.Printf("Creating Pod %q...\n", podName)
	result, err := clientset.CoreV1().Pods("default").Create(context.Background(), pod, metav1.CreateOptions{})
	if err != nil {
		return podName, err
	}
	fmt.Printf("Created Pod %q.\n", result.GetObjectMeta().GetName())

	// Wait for the Pod to be running and ready
	fmt.Printf("Waiting for Pod %q to be ready...\n", podName)
	ready := false
	for i := 0; i < 10; i++ {
		result, err := clientset.CoreV1().Pods("default").Get(context.Background(), podName, metav1.GetOptions{})
		if err != nil {
			return podName, err
		}
		status := result.Status
		if status.Phase == v1.PodRunning && len(status.ContainerStatuses) > 0 && status.ContainerStatuses[0].Ready {
			ready = true
			break
		}
		time.Sleep(2 * time.Second)
	}
	if !ready {
		return podName, errors.New("create pod timeout")
	}
	// Exec into the container
	// Create exec request
	var cmd []string
	if command == "gdb" {
		chmod := "cd" + filepath.Dir(config.Process_exe_path)
		cmd = []string{"gdb", config.Process_exe_path, "/host" + config.Storage, "-ex", chmod}
	} else {
		cmd = []string{command}
	}
	req := clientset.CoreV1().RESTClient().Post().Resource("pods").
		Name(podName).Namespace("default").
		SubResource("exec").
		VersionedParams(&v1.PodExecOptions{
			Container: containerName,
			Command:   cmd,
			Stdin:     true,
			Stdout:    true,
			Stderr:    true,
			TTY:       true,
		}, scheme.ParameterCodec)

	// Create exec executor
	executor, err := remotecommand.NewSPDYExecutor(conf, "POST", req.URL())
	if err != nil {
		return podName, err
	}

	// Start exec
	err = executor.StreamWithContext(context.Background(), remotecommand.StreamOptions{
		Stdin:  os.Stdin,
		Stdout: os.Stdout,
		Stderr: os.Stderr,
		Tty:    true,
	})
	if err != nil {
		return podName, err
	}
	return podName, nil
}

// WalkDirectory 遍历文件目录并处理后缀名为.config的文件
func WalkDirectory(dir string) {
	err := filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if !info.IsDir() {
			if strings.HasSuffix(info.Name(), ".config") {
				data, err := os.ReadFile(path)
				if err != nil {
					return err
				}

				var config types.Coredump_config
				err = json.Unmarshal(data, &config)
				if err != nil {
					return err
				}
				configs = append(configs, config)
			}
		}

		return nil
	})

	if err != nil {
		fmt.Printf("Error walking directory %s: %v\n", dir, err)
	}
}
func list(pid string) {
	defaultWidth := 80
	if width, _, err := terminalSize(); err == nil {
		defaultWidth = int(width)
	}
	// 输出表头信息
	fmt.Printf("%-8s %-3s %-3s %-3s %-20s %-30s %-30s %-100s %-50s\n",
		"PID", "UID", "GID", "SIG", "TIMESTAMP", "EXE", "HOSTNAME", "IMAGE", "STORGE")
	fmt.Println(strings.Repeat("-", defaultWidth))
	total := 0
	// 输出配置信息
	for _, c := range configs {
		if pid != "" && strings.Compare(c.Initial_ns_pid, pid) != 0 {
			continue
		}
		coreTime := time.Unix(c.Timestamp, 0).Format("2006-01-02 15:04:05")
		fmt.Printf("%-8s %-3s %-3s %-6d %-20s %-30s %-30s %-100s %-50s\n",
			c.Initial_ns_pid, c.UID, c.GID, c.Signal, coreTime, c.Process_exe_path, c.Hostname, c.Image_name, c.Storage)
		total += 1
	}
	fmt.Println()
	fmt.Println("Total", total, "coredumps")
}

// Help 打印使用帮助
func Help() {
	fmt.Println("Usage: coredump-ctl [list | debug | help] [options] ")
	fmt.Println("list options:")
	fmt.Println("  -dir string")
	fmt.Println("        Directory path")
	fmt.Println("  -p string")
	fmt.Println("        Pid to matching")
	fmt.Println("  -command string")
	fmt.Println("        exe command when attach to pod")
}

func main() {
	listCmd := flag.NewFlagSet("list", flag.ExitOnError)
	debugCmd := flag.NewFlagSet("debug", flag.ExitOnError)
	helpCmd := flag.NewFlagSet("help", flag.ExitOnError)
	var dirPath, pid, command string
	listCmd.StringVar(&pid, "p", "", "Pid to matching")
	debugCmd.StringVar(&pid, "p", "", "Pid to matching")
	listCmd.StringVar(&dirPath, "dir", "", "Directory path")
	debugCmd.StringVar(&dirPath, "dir", "", "Directory path")
	debugCmd.StringVar(&command, "command", "", "")
	if len(os.Args) == 1 {
		helpCmd.Usage()
		os.Exit(1)
	}
	switch os.Args[1] {
	case "list":
		listCmd.Parse(os.Args[2:])
	case "debug":
		debugCmd.Parse(os.Args[2:])
	case "help":
		helpCmd.Parse(os.Args[2:])
		Help()
	default:
		fmt.Printf("%q is not a valid command.\n", os.Args[1])
		os.Exit(1)
	}
	if listCmd.Parsed() {
		if dirPath == "" {
			dirPath = "/var/tmp"
		}
		WalkDirectory(dirPath)
		list(pid)
		return
	}
	if debugCmd.Parsed() {
		if dirPath == "" {
			dirPath = "/var/tmp"
		}
		if command == "" {
			command = "gdb"
		}
		WalkDirectory(dirPath)
		for _, config := range configs {
			fmt.Println(config)
			if strings.Compare(config.Initial_ns_pid, pid) == 0 || pid == "" {
				err := debug(config, command)
				if err != nil {
					fmt.Println(err)
				} else {
					break
				}
			}
		}
		return
	}
}