/*
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 (
	"fmt"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	bindingsv1alpha1 "knative.dev/eventing-kafka/pkg/apis/bindings/v1alpha1"
	"knative.dev/pkg/apis"
	duckv1 "knative.dev/pkg/apis/duck/v1"
	"knative.dev/pkg/kmeta"
	"knative.dev/pkg/webhook/resourcesemantics"
)

// +genclient
// +genreconciler
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// KafkaSource is the Schema for the kafkasources API.
// +k8s:openapi-gen=true
type KafkaSource struct {
	metav1.TypeMeta   `json:",inline"`
	metav1.ObjectMeta `json:"metadata,omitempty"`

	Spec   KafkaSourceSpec   `json:"spec,omitempty"`
	Status KafkaSourceStatus `json:"status,omitempty"`
}

// Check that KafkaSource can be validated and can be defaulted.
var _ runtime.Object = (*KafkaSource)(nil)
var _ resourcesemantics.GenericCRD = (*KafkaSource)(nil)
var _ kmeta.OwnerRefable = (*KafkaSource)(nil)
var _ apis.Defaultable = (*KafkaSource)(nil)
var _ apis.Validatable = (*KafkaSource)(nil)
var _ duckv1.KRShaped = (*KafkaSource)(nil)

type KafkaRequestsSpec struct {
	ResourceCPU    string `json:"cpu,omitempty"`
	ResourceMemory string `json:"memory,omitempty"`
}

type KafkaLimitsSpec struct {
	ResourceCPU    string `json:"cpu,omitempty"`
	ResourceMemory string `json:"memory,omitempty"`
}

type KafkaResourceSpec struct {
	Requests KafkaRequestsSpec `json:"requests,omitempty"`
	Limits   KafkaLimitsSpec   `json:"limits,omitempty"`
}

// KafkaSourceSpec defines the desired state of the KafkaSource.
type KafkaSourceSpec struct {
	bindingsv1alpha1.KafkaAuthSpec `json:",inline"`

	// Topic topics to consume messages from
	// +required
	Topics []string `json:"topics"`

	// ConsumerGroupID is the consumer group ID.
	// +optional
	ConsumerGroup string `json:"consumerGroup,omitempty"`

	// Sink is a reference to an object that will resolve to a domain name to use as the sink.
	// +optional
	Sink *duckv1.Destination `json:"sink,omitempty"`

	// ServiceAccoutName is the name of the ServiceAccount that will be used to run the Receive
	// Adapter Deployment.
	// Deprecated: v1beta1 drops this field.
	ServiceAccountName string `json:"serviceAccountName,omitempty"`

	// Resource limits and Request specifications of the Receive Adapter Deployment
	// Deprecated: v1beta1 drops this field.
	Resources KafkaResourceSpec `json:"resources,omitempty"`

	// CloudEventOverrides defines overrides to control the output format and
	// modifications of the event sent to the sink.
	// +optional
	// Needed for supporting round-tripping
	CloudEventOverrides *duckv1.CloudEventOverrides `json:"ceOverrides,omitempty"`

	// Number of desired consumers running in the consumer group. Defaults to 1.
	//
	// This is a pointer to distinguish between explicit
	// zero and not specified.
	// For round-tripping only.
	// +optional
	Consumers *int32 `json:"consumers,omitempty"`
}

const (
	// KafkaEventType is the Kafka CloudEvent type.
	KafkaEventType = "dev.knative.kafka.event"

	KafkaKeyTypeLabel = "kafkasources.sources.knative.dev/key-type"
)

var KafkaKeyTypeAllowed = []string{"string", "int", "float", "byte-array"}

// KafkaEventSource returns the Kafka CloudEvent source.
func KafkaEventSource(namespace, kafkaSourceName, topic string) string {
	return fmt.Sprintf("/apis/v1/namespaces/%s/kafkasources/%s#%s", namespace, kafkaSourceName, topic)
}

// KafkaSourceStatus defines the observed state of KafkaSource.
type KafkaSourceStatus struct {
	// inherits duck/v1 SourceStatus, 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.
	// * SinkURI - the current active sink URI that has been configured for the
	//   Source.
	duckv1.SourceStatus `json:",inline"`

	// Total number of consumers actually running in the consumer group.
	// +optional
	// For round-tripping only.
	Consumers int32 `json:"consumers,omitempty"`
}

func (*KafkaSource) GetGroupVersionKind() schema.GroupVersionKind {
	return SchemeGroupVersion.WithKind("KafkaSource")
}

// GetStatus retrieves the duck status for this resource. Implements the KRShaped interface.
func (k *KafkaSource) GetStatus() *duckv1.Status {
	return &k.Status.Status
}

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

// KafkaSourceList contains a list of KafkaSources.
type KafkaSourceList struct {
	metav1.TypeMeta `json:",inline"`
	metav1.ListMeta `json:"metadata,omitempty"`
	Items           []KafkaSource `json:"items"`
}
