/*
Copyright 2016 The Kubernetes Authors.
Copyright 2020 Authors of Arktos - file modified.

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 kubeapiserver

import (
	"strings"

	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	serveroptions "k8s.io/apiserver/pkg/server/options"
	"k8s.io/apiserver/pkg/server/options/encryptionconfig"
	"k8s.io/apiserver/pkg/server/resourceconfig"
	serverstorage "k8s.io/apiserver/pkg/server/storage"
	"k8s.io/apiserver/pkg/storage/storagebackend"
	"k8s.io/kubernetes/pkg/api/legacyscheme"
	"k8s.io/kubernetes/pkg/apis/apps"
	"k8s.io/kubernetes/pkg/apis/batch"
	api "k8s.io/kubernetes/pkg/apis/core"
	"k8s.io/kubernetes/pkg/apis/events"
	"k8s.io/kubernetes/pkg/apis/extensions"
	"k8s.io/kubernetes/pkg/apis/networking"
	"k8s.io/kubernetes/pkg/apis/policy"
	apisstorage "k8s.io/kubernetes/pkg/apis/storage"
)

// SpecialDefaultResourcePrefixes are prefixes compiled into Kubernetes.
var SpecialDefaultResourcePrefixes = map[schema.GroupResource]string{
	{Group: "", Resource: "replicationcontrollers"}:        "controllers",
	{Group: "", Resource: "endpoints"}:                     "services/endpoints",
	{Group: "", Resource: "nodes"}:                         "minions",
	{Group: "", Resource: "services"}:                      "services/specs",
	{Group: "extensions", Resource: "ingresses"}:           "ingress",
	{Group: "networking.k8s.io", Resource: "ingresses"}:    "ingress",
	{Group: "extensions", Resource: "podsecuritypolicies"}: "podsecuritypolicy",
	{Group: "policy", Resource: "podsecuritypolicies"}:     "podsecuritypolicy",
}

func NewStorageFactoryConfig() *StorageFactoryConfig {

	resources := []schema.GroupVersionResource{
		batch.Resource("cronjobs").WithVersion("v1beta1"),
		networking.Resource("ingresses").WithVersion("v1beta1"),
		// TODO #83513 csinodes override can be removed in 1.18
		apisstorage.Resource("csinodes").WithVersion("v1beta1"),
		apisstorage.Resource("csidrivers").WithVersion("v1beta1"),
	}

	return &StorageFactoryConfig{
		Serializer:                legacyscheme.Codecs,
		DefaultResourceEncoding:   serverstorage.NewDefaultResourceEncodingConfig(legacyscheme.Scheme),
		ResourceEncodingOverrides: resources,
	}
}

type StorageFactoryConfig struct {
	StorageConfig                    storagebackend.Config
	ApiResourceConfig                *serverstorage.ResourceConfig
	DefaultResourceEncoding          *serverstorage.DefaultResourceEncodingConfig
	DefaultStorageMediaType          string
	Serializer                       runtime.StorageSerializer
	ResourceEncodingOverrides        []schema.GroupVersionResource
	EtcdServersOverrides             []string
	EncryptionProviderConfigFilepath string
}

func (c *StorageFactoryConfig) Complete(etcdOptions *serveroptions.EtcdOptions) (*completedStorageFactoryConfig, error) {
	c.StorageConfig = etcdOptions.StorageConfig
	c.DefaultStorageMediaType = etcdOptions.DefaultStorageMediaType
	c.EtcdServersOverrides = etcdOptions.EtcdServersOverrides
	c.EncryptionProviderConfigFilepath = etcdOptions.EncryptionProviderConfigFilepath
	return &completedStorageFactoryConfig{c}, nil
}

type completedStorageFactoryConfig struct {
	*StorageFactoryConfig
}

func (c *completedStorageFactoryConfig) New() (*serverstorage.DefaultStorageFactory, error) {
	resourceEncodingConfig := resourceconfig.MergeResourceEncodingConfigs(c.DefaultResourceEncoding, c.ResourceEncodingOverrides)
	storageFactory := serverstorage.NewDefaultStorageFactory(
		c.StorageConfig,
		c.DefaultStorageMediaType,
		c.Serializer,
		resourceEncodingConfig,
		c.ApiResourceConfig,
		SpecialDefaultResourcePrefixes)

	storageFactory.AddCohabitatingResources(networking.Resource("networkpolicies"), extensions.Resource("networkpolicies"))
	storageFactory.AddCohabitatingResources(apps.Resource("deployments"), extensions.Resource("deployments"))
	storageFactory.AddCohabitatingResources(apps.Resource("daemonsets"), extensions.Resource("daemonsets"))
	storageFactory.AddCohabitatingResources(apps.Resource("replicasets"), extensions.Resource("replicasets"))
	storageFactory.AddCohabitatingResources(api.Resource("events"), events.Resource("events"))
	storageFactory.AddCohabitatingResources(api.Resource("replicationcontrollers"), extensions.Resource("replicationcontrollers")) // to make scale subresources equivalent
	storageFactory.AddCohabitatingResources(policy.Resource("podsecuritypolicies"), extensions.Resource("podsecuritypolicies"))
	storageFactory.AddCohabitatingResources(networking.Resource("ingresses"), extensions.Resource("ingresses"))

	for _, override := range c.EtcdServersOverrides {
		tokens := strings.Split(override, "#")
		apiresource := strings.Split(tokens[0], "/")

		group := apiresource[0]
		resource := apiresource[1]
		groupResource := schema.GroupResource{Group: group, Resource: resource}

		servers := strings.Split(tokens[1], ";")
		storageFactory.SetEtcdLocation(groupResource, servers)
	}
	if len(c.EncryptionProviderConfigFilepath) != 0 {
		transformerOverrides, err := encryptionconfig.GetTransformerOverrides(c.EncryptionProviderConfigFilepath)
		if err != nil {
			return nil, err
		}
		for groupResource, transformer := range transformerOverrides {
			storageFactory.SetTransformer(groupResource, transformer)
		}
	}
	return storageFactory, nil
}
