/*
Copyright 2017 The Kubernetes Authors.

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 admissionregistration

import (
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

// +genclient=true
// +nonNamespaced=true

// InitializerConfiguration describes the configuration of initializers.
type InitializerConfiguration struct {
	metav1.TypeMeta
	// Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata.
	// +optional
	metav1.ObjectMeta

	// Initializers is a list of resources and their default initializers
	// Order-sensitive.
	// When merging multiple InitializerConfigurations, we sort the initializers
	// from different InitializerConfigurations by the name of the
	// InitializerConfigurations; the order of the initializers from the same
	// InitializerConfiguration is preserved.
	// +optional
	Initializers []Initializer
}

// InitializerConfigurationList is a list of InitializerConfiguration.
type InitializerConfigurationList struct {
	metav1.TypeMeta
	// Standard list metadata.
	// More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds
	// +optional
	metav1.ListMeta

	// List of InitializerConfiguration.
	Items []InitializerConfiguration
}

// Initializer describes the name and the failure policy of an initializer, and
// what resources it applies to.
type Initializer struct {
	// Name is the identifier of the initializer. It will be added to the
	// object that needs to be initialized.
	// Name should be fully qualified, e.g., alwayspullimages.kubernetes.io, where
	// "alwayspullimages" is the name of the webhook, and kubernetes.io is the name
	// of the organization.
	// Required
	Name string

	// Rules describes what resources/subresources the initializer cares about.
	// The initializer cares about an operation if it matches _any_ Rule.
	// Rule.Resources must not include subresources.
	Rules []Rule

	// FailurePolicy defines what happens if the responsible initializer controller
	// fails to takes action. Allowed values are Ignore, or Fail. If "Ignore" is
	// set, initializer is removed from the initializers list of an object if
	// the timeout is reached; If "Fail" is set, admissionregistration returns timeout error
	// if the timeout is reached.
	FailurePolicy *FailurePolicyType
}

// Rule is a tuple of APIGroups, APIVersion, and Resources.It is recommended
// to make sure that all the tuple expansions are valid.
type Rule struct {
	// APIGroups is the API groups the resources belong to. '*' is all groups.
	// If '*' is present, the length of the slice must be one.
	// Required.
	APIGroups []string

	// APIVersions is the API versions the resources belong to. '*' is all versions.
	// If '*' is present, the length of the slice must be one.
	// Required.
	APIVersions []string

	// Resources is a list of resources this rule applies to.
	//
	// For example:
	// 'pods' means pods.
	// 'pods/log' means the log subresource of pods.
	// '*' means all resources, but not subresources.
	// 'pods/*' means all subresources of pods.
	// '*/scale' means all scale subresources.
	// '*/*' means all resources and their subresources.
	//
	// If wildcard is present, the validation rule will ensure resources do not
	// overlap with each other.
	//
	// Depending on the enclosing object, subresources might not be allowed.
	// Required.
	Resources []string
}

type FailurePolicyType string

const (
	// Ignore means the initilizer is removed from the initializers list of an
	// object if the initializer is timed out.
	Ignore FailurePolicyType = "Ignore"
	// For 1.7, only "Ignore" is allowed. "Fail" will be allowed when the
	// extensible admission feature is beta.
	Fail FailurePolicyType = "Fail"
)

// +genclient=true
// +nonNamespaced=true

// ExternalAdmissionHookConfiguration describes the configuration of initializers.
type ExternalAdmissionHookConfiguration struct {
	metav1.TypeMeta
	// Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata.
	// +optional
	metav1.ObjectMeta
	// ExternalAdmissionHooks is a list of external admission webhooks and the
	// affected resources and operations.
	// +optional
	ExternalAdmissionHooks []ExternalAdmissionHook
}

// ExternalAdmissionHookConfigurationList is a list of ExternalAdmissionHookConfiguration.
type ExternalAdmissionHookConfigurationList struct {
	metav1.TypeMeta
	// Standard list metadata.
	// More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds
	// +optional
	metav1.ListMeta
	// List of ExternalAdmissionHookConfiguration.
	Items []ExternalAdmissionHookConfiguration
}

// ExternalAdmissionHook describes an external admission webhook and the
// resources and operations it applies to.
type ExternalAdmissionHook struct {
	// The name of the external admission webhook.
	// Name should be fully qualified, e.g., imagepolicy.kubernetes.io, where
	// "imagepolicy" is the name of the webhook, and kubernetes.io is the name
	// of the organization.
	// Required.
	Name string

	// ClientConfig defines how to communicate with the hook.
	// Required
	ClientConfig AdmissionHookClientConfig

	// Rules describes what operations on what resources/subresources the webhook cares about.
	// The webhook cares about an operation if it matches _any_ Rule.
	Rules []RuleWithOperations

	// FailurePolicy defines how unrecognized errors from the admission endpoint are handled -
	// allowed values are Ignore or Fail. Defaults to Ignore.
	// +optional
	FailurePolicy *FailurePolicyType
}

// RuleWithOperations is a tuple of Operations and Resources. It is recommended to make
// sure that all the tuple expansions are valid.
type RuleWithOperations struct {
	// Operations is the operations the admission hook cares about - CREATE, UPDATE, or *
	// for all operations.
	// If '*' is present, the length of the slice must be one.
	// Required.
	Operations []OperationType
	// Rule is embedded, it describes other criteria of the rule, like
	// APIGroups, APIVersions, Resources, etc.
	Rule
}

type OperationType string

// The constants should be kept in sync with those defined in k8s.io/kubernetes/pkg/admission/interface.go.
const (
	OperationAll OperationType = "*"
	Create       OperationType = "CREATE"
	Update       OperationType = "UPDATE"
	Delete       OperationType = "DELETE"
	Connect      OperationType = "CONNECT"
)

// AdmissionHookClientConfig contains the information to make a TLS
// connection with the webhook
type AdmissionHookClientConfig struct {
	// Service is a reference to the service for this webhook. If there is only
	// one port open for the service, that port will be used. If there are multiple
	// ports open, port 443 will be used if it is open, otherwise it is an error.
	// Required
	Service ServiceReference
	// CABundle is a PEM encoded CA bundle which will be used to validate webhook's server certificate.
	// Required
	CABundle []byte
}

// ServiceReference holds a reference to Service.legacy.k8s.io
type ServiceReference struct {
	// Namespace is the namespace of the service
	// Required
	Namespace string
	// Name is the name of the service
	// Required
	Name string
}
