/*
Copyright 2019 The Rook Authors. All rights reserved.

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 csi

import (
	"bytes"
	"io/ioutil"
	"path/filepath"
	"strconv"
	"strings"
	"text/template"

	"github.com/ghodss/yaml"
	"github.com/pkg/errors"
	"github.com/rook/rook/pkg/operator/ceph/controller"
	k8sutil "github.com/rook/rook/pkg/operator/k8sutil"
	apps "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
)

func loadTemplate(name, templatePath string, p templateParam) (string, error) {
	b, err := ioutil.ReadFile(filepath.Clean(templatePath))
	if err != nil {
		return "", err
	}
	data := string(b)
	var writer bytes.Buffer
	t := template.New(name)
	t, err = t.Parse(data)
	if err != nil {
		return "", errors.Wrapf(err, "failed to parse template %v", name)
	}
	err = t.Execute(&writer, p)
	return writer.String(), err
}

func templateToService(name, templatePath string, p templateParam) (*corev1.Service, error) {
	var svc corev1.Service
	t, err := loadTemplate(name, templatePath, p)
	if err != nil {
		return nil, errors.Wrap(err, "failed to load service template")
	}

	err = yaml.Unmarshal([]byte(t), &svc)
	if err != nil {
		return nil, errors.Wrap(err, "failed to unmarshal service template")
	}
	return &svc, nil
}

func templateToDaemonSet(name, templatePath string, p templateParam) (*apps.DaemonSet, error) {
	var ds apps.DaemonSet
	t, err := loadTemplate(name, templatePath, p)
	if err != nil {
		return nil, errors.Wrap(err, "failed to load daemonset template")
	}

	err = yaml.Unmarshal([]byte(t), &ds)
	if err != nil {
		return nil, errors.Wrap(err, "failed to unmarshal daemonset template")
	}
	return &ds, nil
}

func templateToDeployment(name, templatePath string, p templateParam) (*apps.Deployment, error) {
	var ds apps.Deployment
	t, err := loadTemplate(name, templatePath, p)
	if err != nil {
		return nil, errors.Wrap(err, "failed to load deployment template")
	}

	err = yaml.Unmarshal([]byte(t), &ds)
	if err != nil {
		return nil, errors.Wrapf(err, "failed to unmarshal deployment template")
	}
	return &ds, nil
}

func applyResourcesToContainers(clientset kubernetes.Interface, key string, podspec *corev1.PodSpec) {
	resource := getComputeResource(clientset, key)
	if len(resource) > 0 {
		for i, c := range podspec.Containers {
			for _, r := range resource {
				if c.Name == r.Name {
					podspec.Containers[i].Resources = r.Resource
				}
			}
		}
	}
}

func getComputeResource(clientset kubernetes.Interface, key string) []k8sutil.ContainerResource {
	// Add Resource list if any
	resource := []k8sutil.ContainerResource{}
	resourceRaw := ""
	var err error

	resourceRaw, err = k8sutil.GetOperatorSetting(clientset, controller.OperatorSettingConfigMapName, key, "")

	if err != nil {
		logger.Warningf("resource requirement for %q will not be applied. %v", key, err)
	}

	if resourceRaw != "" {
		resource, err = k8sutil.YamlToContainerResource(resourceRaw)
		if err != nil {
			logger.Warningf("failed to parse %q. %v", resourceRaw, err)
		}
	}
	return resource
}

func getToleration(clientset kubernetes.Interface, tolerationsName string, defaultTolerations []corev1.Toleration) []corev1.Toleration {
	// Add toleration if any, otherwise return defaultTolerations
	tolerationsRaw, err := k8sutil.GetOperatorSetting(clientset, controller.OperatorSettingConfigMapName, tolerationsName, "")
	if err != nil {
		logger.Warningf("failed to read %q. %v", tolerationsName, err)
		return defaultTolerations
	}
	if tolerationsRaw == "" {
		return defaultTolerations
	}
	tolerations, err := k8sutil.YamlToTolerations(tolerationsRaw)
	if err != nil {
		logger.Warningf("failed to parse %q for %q. %v", tolerationsRaw, tolerationsName, err)
		return defaultTolerations
	}
	for i := range tolerations {
		if tolerations[i].Key == "" {
			tolerations[i].Operator = corev1.TolerationOpExists
		}

		if tolerations[i].Operator == corev1.TolerationOpExists {
			tolerations[i].Value = ""
		}
	}
	return tolerations
}

func getNodeAffinity(clientset kubernetes.Interface, nodeAffinityName string, defaultNodeAffinity *corev1.NodeAffinity) *corev1.NodeAffinity {
	// Add NodeAffinity if any, otherwise return defaultNodeAffinity
	nodeAffinity, err := k8sutil.GetOperatorSetting(clientset, controller.OperatorSettingConfigMapName, nodeAffinityName, "")
	if err != nil {
		logger.Warningf("failed to read %q. %v", nodeAffinityName, err)
		return defaultNodeAffinity
	}
	if nodeAffinity == "" {
		return defaultNodeAffinity
	}
	v1NodeAffinity, err := k8sutil.GenerateNodeAffinity(nodeAffinity)
	if err != nil {
		logger.Warningf("failed to parse %q for %q. %v", nodeAffinity, nodeAffinityName, err)
		return defaultNodeAffinity
	}
	return v1NodeAffinity
}

func applyToPodSpec(pod *corev1.PodSpec, n *corev1.NodeAffinity, t []corev1.Toleration) {
	pod.Tolerations = t
	pod.Affinity = &corev1.Affinity{
		NodeAffinity: n,
	}
}

func getPortFromConfig(clientset kubernetes.Interface, env string, defaultPort uint16) (uint16, error) {
	port, err := k8sutil.GetOperatorSetting(clientset, controller.OperatorSettingConfigMapName, env, strconv.Itoa(int(defaultPort)))
	if err != nil {
		return defaultPort, errors.Wrapf(err, "failed to load value for %q.", env)
	}
	if strings.TrimSpace(port) == "" {
		return defaultPort, nil
	}
	p, err := strconv.ParseUint(port, 10, 64)
	if err != nil {
		return defaultPort, errors.Wrapf(err, "failed to parse port value for %q.", env)
	}
	if p > 65535 {
		return defaultPort, errors.Errorf("%s port value is greater than 65535 for %s.", port, env)
	}
	return uint16(p), nil
}

// Get PodAntiAffinity from a key and value pair
func GetPodAntiAffinity(key, value string) corev1.PodAntiAffinity {
	return corev1.PodAntiAffinity{
		RequiredDuringSchedulingIgnoredDuringExecution: []corev1.PodAffinityTerm{
			{
				LabelSelector: &metav1.LabelSelector{
					MatchExpressions: []metav1.LabelSelectorRequirement{
						{
							Key:      key,
							Operator: metav1.LabelSelectorOpIn,
							Values:   []string{value},
						},
					},
				},
				TopologyKey: corev1.LabelHostname,
			},
		},
	}
}
