package services

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"strings"

	"lokideploy/models"
)

type ClusterInfo struct {
	Version    string     `json:"version"`
	Nodes      []NodeInfo `json:"nodes"`
	Namespaces []string   `json:"namespaces"`
	Contexts   []string   `json:"contexts"`
	CurrentCtx string     `json:"currentContext"`
}

type NodeInfo struct {
	Name       string            `json:"name"`
	Status     string            `json:"status"`
	Roles      []string          `json:"roles"`
	Version    string            `json:"version"`
	OS         string            `json:"os"`
	Arch       string            `json:"arch"`
	InternalIP string            `json:"internalIP"`
	Labels     map[string]string `json:"labels"`
}

// GetClusterInfo 通过 kubectl 查询集群信息。
// Token 接入的集群在创建时已构造等价 kubeconfig，因此 kubectl 同样适用。
func GetClusterInfo(ctx context.Context, cluster *models.Cluster) (*ClusterInfo, error) {
	kubeconfig, err := resolveKubeconfig(cluster)
	if err != nil {
		return nil, err
	}

	kubeFile, err := os.CreateTemp("", "kube-*.yaml")
	if err != nil {
		return nil, err
	}
	defer os.Remove(kubeFile.Name())
	kubeFile.WriteString(kubeconfig)
	kubeFile.Close()

	env := append(os.Environ(), fmt.Sprintf("KUBECONFIG=%s", kubeFile.Name()))

	info := &ClusterInfo{
		Nodes:      []NodeInfo{},
		Namespaces: []string{},
		Contexts:   []string{},
	}

	// Version（best-effort）
	if versionOut, err := runCmd(ctx, env, "kubectl", "version", "-o", "json"); err == nil {
		var versionData struct {
			ServerVersion struct {
				GitVersion string `json:"gitVersion"`
			} `json:"serverVersion"`
		}
		json.Unmarshal(versionOut, &versionData)
		info.Version = versionData.ServerVersion.GitVersion
	}

	// Nodes
	nodesOut, err := runCmd(ctx, env, "kubectl", "get", "nodes", "-o", "json")
	if err != nil {
		return nil, fmt.Errorf("获取节点列表失败: %v", err)
	}
	var nodesData struct {
		Items []struct {
			Metadata struct {
				Name   string            `json:"name"`
				Labels map[string]string `json:"labels"`
			} `json:"metadata"`
			Status struct {
				Conditions []struct {
					Type   string `json:"type"`
					Status string `json:"status"`
				} `json:"conditions"`
				NodeInfo struct {
					KubeletVersion  string `json:"kubeletVersion"`
					OperatingSystem string `json:"operatingSystem"`
					Architecture    string `json:"architecture"`
				} `json:"nodeInfo"`
				Addresses []struct {
					Type    string `json:"type"`
					Address string `json:"address"`
				} `json:"addresses"`
			} `json:"status"`
		} `json:"items"`
	}
	json.Unmarshal(nodesOut, &nodesData)

	for _, item := range nodesData.Items {
		status := "Unknown"
		for _, cond := range item.Status.Conditions {
			if cond.Type == "Ready" {
				if cond.Status == "True" {
					status = "Ready"
				} else {
					status = "NotReady"
				}
				break
			}
		}
		var roles []string
		for label := range item.Metadata.Labels {
			if strings.HasPrefix(label, "node-role.kubernetes.io/") {
				roles = append(roles, label[len("node-role.kubernetes.io/"):])
			}
		}
		if len(roles) == 0 {
			roles = []string{"worker"}
		}
		internalIP := ""
		for _, addr := range item.Status.Addresses {
			if addr.Type == "InternalIP" {
				internalIP = addr.Address
				break
			}
		}
		info.Nodes = append(info.Nodes, NodeInfo{
			Name:       item.Metadata.Name,
			Status:     status,
			Roles:      roles,
			Version:    item.Status.NodeInfo.KubeletVersion,
			OS:         item.Status.NodeInfo.OperatingSystem,
			Arch:       item.Status.NodeInfo.Architecture,
			InternalIP: internalIP,
			Labels:     item.Metadata.Labels,
		})
	}

	// Namespaces（best-effort）
	if nsOut, err := runCmd(ctx, env, "kubectl", "get", "ns", "-o", "jsonpath={.items[*].metadata.name}"); err == nil {
		info.Namespaces = strings.Fields(string(nsOut))
	}

	// Contexts（best-effort）
	if ctxOut, err := runCmd(ctx, env, "kubectl", "config", "get-contexts", "-o", "name"); err == nil {
		for _, line := range strings.Split(strings.TrimSpace(string(ctxOut)), "\n") {
			if line = strings.TrimSpace(line); line != "" {
				info.Contexts = append(info.Contexts, line)
			}
		}
	}

	// Current context（best-effort）
	if currentCtxOut, err := runCmd(ctx, env, "kubectl", "config", "current-context"); err == nil {
		info.CurrentCtx = strings.TrimSpace(string(currentCtxOut))
	}

	return info, nil
}

func runCmd(ctx context.Context, env []string, name string, args ...string) ([]byte, error) {
	cmd := exec.CommandContext(ctx, name, args...)
	cmd.Env = env
	return cmd.CombinedOutput()
}