package services

import (
	"context"
	"fmt"
	"regexp"
	"sort"
	"time"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"opsxloki/models"
)

type ClusterDeploymentOption struct {
	Name          string `json:"name"`
	Replicas      int    `json:"replicas"`
	ReadyReplicas int    `json:"readyReplicas"`
}

var kubernetesNamespacePattern = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?$`)

func ListClusterNamespaces(ctx context.Context, cluster *models.Cluster) ([]string, error) {
	client, err := clusterClient(cluster, 10*time.Second)
	if err != nil {
		return nil, err
	}
	items, err := client.CoreV1().Namespaces().List(ctx, metav1.ListOptions{})
	if err != nil {
		if apierrors.IsForbidden(err) {
			// 命名空间级 Token 无权枚举命名空间：返回空列表，由用户手填
			return []string{}, nil
		}
		return nil, fmt.Errorf("读取集群命名空间失败: %w", err)
	}
	result := make([]string, 0, len(items.Items))
	for _, item := range items.Items {
		result = append(result, item.Name)
	}
	sort.Strings(result)
	return result, nil
}

func ListClusterDeployments(ctx context.Context, cluster *models.Cluster, namespace string) ([]ClusterDeploymentOption, error) {
	if len(namespace) > 63 || !kubernetesNamespacePattern.MatchString(namespace) {
		return nil, fmt.Errorf("命名空间名称无效")
	}
	client, err := clusterClient(cluster, 10*time.Second)
	if err != nil {
		return nil, err
	}
	items, err := client.AppsV1().Deployments(namespace).List(ctx, metav1.ListOptions{})
	if err != nil {
		return nil, fmt.Errorf("读取集群 Deployment 失败: %w", err)
	}
	result := make([]ClusterDeploymentOption, 0, len(items.Items))
	for _, item := range items.Items {
		replicas := int32(1)
		if item.Spec.Replicas != nil {
			replicas = *item.Spec.Replicas
		}
		result = append(result, ClusterDeploymentOption{
			Name: item.Name, Replicas: int(replicas), ReadyReplicas: int(item.Status.ReadyReplicas),
		})
	}
	sort.Slice(result, func(i, j int) bool { return result[i].Name < result[j].Name })
	return result, nil
}