package kube

import (
	"fmt"
	"os"
	"path/filepath"

	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
)

// NewClient builds a Kubernetes clientset. It tries in-cluster config first
// (running inside a pod), then falls back to ~/.kube/config for local use.
func NewClient() (*kubernetes.Clientset, error) {
	cfg, err := rest.InClusterConfig()
	if err != nil {
		home, _ := os.UserHomeDir()
		kubeconfig := filepath.Join(home, ".kube", "config")
		if kc := os.Getenv("KUBECONFIG"); kc != "" {
			kubeconfig = kc
		}
		cfg, err = clientcmd.BuildConfigFromFlags("", kubeconfig)
		if err != nil {
			return nil, fmt.Errorf("kube: build config: %w", err)
		}
	}
	client, err := kubernetes.NewForConfig(cfg)
	if err != nil {
		return nil, fmt.Errorf("kube: new client: %w", err)
	}
	return client, nil
}