/*
 * Copyright 2019 The Knative 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 v1alpha1

import (
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	eventingduckv1beta1 "knative.dev/eventing/pkg/apis/duck/v1beta1"
	messagingv1beta1 "knative.dev/eventing/pkg/apis/messaging/v1beta1"
	"knative.dev/pkg/apis"
	duckv1 "knative.dev/pkg/apis/duck/v1"
	duckv1alpha1 "knative.dev/pkg/apis/duck/v1alpha1"
	"knative.dev/pkg/kmeta"
)

// +genclient
// +genreconciler
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

// Broker collects a pool of events that are consumable using Triggers. Brokers
// provide a well-known endpoint for event delivery that senders can use with
// minimal knowledge of the event routing strategy. Receivers use Triggers to
// request delivery of events from a Broker's pool to a specific URL or
// Addressable endpoint.
type Broker struct {
	metav1.TypeMeta `json:",inline"`
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty"`

	// Spec defines the desired state of the Broker.
	Spec BrokerSpec `json:"spec,omitempty"`

	// Status represents the current state of the Broker. This data may be out of
	// date.
	// +optional
	Status BrokerStatus `json:"status,omitempty"`
}

var (
	// Check that Broker can be validated, can be defaulted, and has immutable fields.
	_ apis.Validatable = (*Broker)(nil)
	_ apis.Defaultable = (*Broker)(nil)

	// Check that Broker can return its spec untyped.
	_ apis.HasSpec = (*Broker)(nil)

	_ runtime.Object = (*Broker)(nil)

	// Check that we can create OwnerReferences to a Broker.
	_ kmeta.OwnerRefable = (*Broker)(nil)
)

type BrokerSpec struct {
	// ChannelTemplate specifies which Channel CRD to use to create all the Channels used internally by the
	// Broker. If left unspecified, it is set to the default Channel CRD for the namespace (or cluster, in case there
	// are no defaults for the namespace).
	// +optional
	// Deprecated: See spec.config to configure aditional broker options.
	// Unless class is <TBD> for channel based broker implementation.
	ChannelTemplate *messagingv1beta1.ChannelTemplateSpec `json:"channelTemplateSpec,omitempty"`

	// Config is a KReference to the configuration that specifies
	// configuration options for this Broker. For example, this could be
	// a pointer to a ConfigMap.
	// NOTE: this is for backwards compatibility with v1alpha1 <-> v1beta1 conversions.
	// +optional
	Config *duckv1.KReference `json:"config,omitempty"`

	// Delivery is the delivery specification to be used internally by the broker to
	// create subscriptions.
	// +optional
	Delivery *eventingduckv1beta1.DeliverySpec `json:"delivery,omitempty"`
}

// BrokerStatus represents the current state of a Broker.
type BrokerStatus struct {
	// inherits duck/v1 Status, which currently provides:
	// * ObservedGeneration - the 'Generation' of the Service that was last processed by the controller.
	// * Conditions - the latest available observations of a resource's current state.
	duckv1.Status `json:",inline"`

	// Broker is Addressable. It currently exposes the endpoint as a
	// fully-qualified DNS name which will distribute traffic over the
	// provided targets from inside the cluster.
	//
	// It generally has the form {broker}-router.{namespace}.svc.{cluster domain name}
	Address duckv1alpha1.Addressable `json:"address,omitempty"`

	// TriggerChannel is an objectref to the object for the TriggerChannel
	TriggerChannel *corev1.ObjectReference `json:"triggerChannel,omitempty"`
}

// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

// BrokerList is a collection of Brokers.
type BrokerList struct {
	metav1.TypeMeta `json:",inline"`
	// +optional
	metav1.ListMeta `json:"metadata,omitempty"`
	Items           []Broker `json:"items"`
}

// GetGroupVersionKind returns GroupVersionKind for Brokers
func (t *Broker) GetGroupVersionKind() schema.GroupVersionKind {
	return SchemeGroupVersion.WithKind("Broker")
}

// GetUntypedSpec returns the spec of the Broker.
func (b *Broker) GetUntypedSpec() interface{} {
	return b.Spec
}
