/*
Copyright 2018 Intel Corporation.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"io/ioutil"
	"log"
	"os"

	"k8s.io/client-go/kubernetes"

	pkgerrors "github.com/pkg/errors"

	coreV1 "k8s.io/api/core/v1"
	metaV1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes/scheme"

	"k8splugin/krd"
)

// CreateResource object in a specific Kubernetes Deployment
func CreateResource(kubedata *krd.GenericKubeResourceData, kubeclient *kubernetes.Clientset) (string, error) {
	if kubedata.Namespace == "" {
		kubedata.Namespace = "default"
	}

	if _, err := os.Stat(kubedata.YamlFilePath); err != nil {
		return "", pkgerrors.New("File " + kubedata.YamlFilePath + " not found")
	}

	log.Println("Reading service YAML")
	rawBytes, err := ioutil.ReadFile(kubedata.YamlFilePath)
	if err != nil {
		return "", pkgerrors.Wrap(err, "Service YAML file read error")
	}

	log.Println("Decoding service YAML")
	decode := scheme.Codecs.UniversalDeserializer().Decode
	obj, _, err := decode(rawBytes, nil, nil)
	if err != nil {
		return "", pkgerrors.Wrap(err, "Deserialize service error")
	}

	switch o := obj.(type) {
	case *coreV1.Service:
		kubedata.ServiceData = o
	default:
		return "", pkgerrors.New(kubedata.YamlFilePath + " contains another resource different than Service")
	}

	kubedata.ServiceData.Namespace = kubedata.Namespace
	kubedata.ServiceData.Name = kubedata.InternalVNFID + "-" + kubedata.ServiceData.Name

	result, err := kubeclient.CoreV1().Services(kubedata.Namespace).Create(kubedata.ServiceData)
	if err != nil {
		return "", pkgerrors.Wrap(err, "Create Service error")
	}
	return result.GetObjectMeta().GetName(), nil
}

// ListResources of existing deployments hosted in a specific Kubernetes Deployment
func ListResources(limit int64, namespace string, kubeclient *kubernetes.Clientset) (*[]string, error) {
	if namespace == "" {
		namespace = "default"
	}
	opts := metaV1.ListOptions{
		Limit: limit,
	}
	opts.APIVersion = "apps/v1"
	opts.Kind = "Service"

	list, err := kubeclient.CoreV1().Services(namespace).List(opts)
	if err != nil {
		return nil, pkgerrors.Wrap(err, "Get Service list error")
	}
	result := make([]string, 0, limit)
	if list != nil {
		for _, service := range list.Items {
			result = append(result, service.Name)
		}
	}
	return &result, nil
}

// DeleteResource deletes an existing Kubernetes service
func DeleteResource(name string, namespace string, kubeclient *kubernetes.Clientset) error {
	if namespace == "" {
		namespace = "default"
	}

	log.Println("Deleting service: " + name)

	deletePolicy := metaV1.DeletePropagationForeground
	err := kubeclient.CoreV1().Services(namespace).Delete(name, &metaV1.DeleteOptions{
		PropagationPolicy: &deletePolicy,
	})
	if err != nil {
		return pkgerrors.Wrap(err, "Delete Service error")
	}

	return nil
}

// GetResource existing service hosting in a specific Kubernetes Service
func GetResource(name string, namespace string, kubeclient *kubernetes.Clientset) (string, error) {
	if namespace == "" {
		namespace = "default"
	}

	opts := metaV1.GetOptions{}
	opts.APIVersion = "apps/v1"
	opts.Kind = "Service"

	service, err := kubeclient.CoreV1().Services(namespace).Get(name, opts)
	if err != nil {
		return "", pkgerrors.Wrap(err, "Get Deployment error")
	}

	return service.Name, nil
}