/*
Copyright (c) Edgeless Systems GmbH

SPDX-License-Identifier: AGPL-3.0-only
*/

/*
Package kubernetes provides functions to interact with a live cluster to the CLI.

Currently it is used to implement the status and upgrade commands.
*/
package kubernetes

import (
	"context"
	"fmt"

	"github.com/edgelesssys/constellation/v2/internal/constants"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
)

func newClient(kubeconfigPath string) (kubernetes.Interface, error) {
	kubeConfig, err := clientcmd.BuildConfigFromFlags("", kubeconfigPath)
	if err != nil {
		return nil, fmt.Errorf("building kubernetes config: %w", err)
	}

	kubeClient, err := kubernetes.NewForConfig(kubeConfig)
	if err != nil {
		return nil, fmt.Errorf("setting up kubernetes client: %w", err)
	}
	return kubeClient, nil
}

// StableInterface is an interface to interact with stable resources.
type StableInterface interface {
	GetCurrentConfigMap(ctx context.Context, name string) (*corev1.ConfigMap, error)
	UpdateConfigMap(ctx context.Context, configMap *corev1.ConfigMap) (*corev1.ConfigMap, error)
	CreateConfigMap(ctx context.Context, configMap *corev1.ConfigMap) (*corev1.ConfigMap, error)
	KubernetesVersion() (string, error)
}

// NewStableClient returns a new StableClient.
func NewStableClient(kubeconfigPath string) (StableInterface, error) {
	client, err := newClient(kubeconfigPath)
	if err != nil {
		return nil, err
	}
	return &stableClient{client}, nil
}

type stableClient struct {
	client kubernetes.Interface
}

// GetCurrentConfigMap returns a ConfigMap given it's name.
func (u *stableClient) GetCurrentConfigMap(ctx context.Context, name string) (*corev1.ConfigMap, error) {
	return u.client.CoreV1().ConfigMaps(constants.ConstellationNamespace).Get(ctx, name, metav1.GetOptions{})
}

// UpdateConfigMap updates the given ConfigMap.
func (u *stableClient) UpdateConfigMap(ctx context.Context, configMap *corev1.ConfigMap) (*corev1.ConfigMap, error) {
	return u.client.CoreV1().ConfigMaps(constants.ConstellationNamespace).Update(ctx, configMap, metav1.UpdateOptions{})
}

// CreateConfigMap creates the given ConfigMap.
func (u *stableClient) CreateConfigMap(ctx context.Context, configMap *corev1.ConfigMap) (*corev1.ConfigMap, error) {
	return u.client.CoreV1().ConfigMaps(constants.ConstellationNamespace).Create(ctx, configMap, metav1.CreateOptions{})
}

// KubernetesVersion returns the Kubernetes version of the cluster.
func (u *stableClient) KubernetesVersion() (string, error) {
	serverVersion, err := u.client.Discovery().ServerVersion()
	if err != nil {
		return "", err
	}
	return serverVersion.GitVersion, nil
}