/*
Copyright 2020 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 v1

import (
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime/schema"
	duckv1 "knative.dev/eventing/pkg/apis/duck/v1"
	messagingv1 "knative.dev/eventing/pkg/apis/messaging/v1"
	"knative.dev/pkg/apis"
	pkgduckv1 "knative.dev/pkg/apis/duck/v1"
)

var pCondSet = apis.NewLivingConditionSet(ParallelConditionReady, ParallelConditionChannelsReady, ParallelConditionSubscriptionsReady, ParallelConditionAddressable)

const (
	// ParallelConditionReady has status True when all subconditions below have been set to True.
	ParallelConditionReady = apis.ConditionReady

	// ParallelConditionChannelsReady has status True when all the channels created as part of
	// this parallel are ready.
	ParallelConditionChannelsReady apis.ConditionType = "ChannelsReady"

	// ParallelConditionSubscriptionsReady has status True when all the subscriptions created as part of
	// this parallel are ready.
	ParallelConditionSubscriptionsReady apis.ConditionType = "SubscriptionsReady"

	// ParallelConditionAddressable has status true when this Parallel meets
	// the Addressable contract and has a non-empty hostname.
	ParallelConditionAddressable apis.ConditionType = "Addressable"
)

// GetConditionSet retrieves the condition set for this resource. Implements the KRShaped interface.
func (*Parallel) GetConditionSet() apis.ConditionSet {
	return pCondSet
}

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

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

// GetCondition returns the condition currently associated with the given type, or nil.
func (ps *ParallelStatus) GetCondition(t apis.ConditionType) *apis.Condition {
	return pCondSet.Manage(ps).GetCondition(t)
}

// IsReady returns true if the resource is ready overall.
func (ps *ParallelStatus) IsReady() bool {
	return pCondSet.Manage(ps).IsHappy()
}

// InitializeConditions sets relevant unset conditions to Unknown state.
func (ps *ParallelStatus) InitializeConditions() {
	pCondSet.Manage(ps).InitializeConditions()
}

// PropagateSubscriptionStatuses sets the ParallelConditionSubscriptionsReady based on
// the status of the incoming subscriptions.
func (ps *ParallelStatus) PropagateSubscriptionStatuses(filterSubscriptions []*messagingv1.Subscription, subscriptions []*messagingv1.Subscription) {
	if ps.BranchStatuses == nil || len(subscriptions) != len(ps.BranchStatuses) {
		ps.BranchStatuses = make([]ParallelBranchStatus, len(subscriptions))
	}
	allReady := true
	// If there are no subscriptions, treat that as a False branch. Could go either way, but this seems right.
	if len(subscriptions) == 0 {
		allReady = false
	}

	for i, s := range subscriptions {
		ps.BranchStatuses[i].SubscriptionStatus = ParallelSubscriptionStatus{
			Subscription: corev1.ObjectReference{
				APIVersion: s.APIVersion,
				Kind:       s.Kind,
				Name:       s.Name,
				Namespace:  s.Namespace,
			},
		}

		readyCondition := s.Status.GetTopLevelCondition()
		if readyCondition != nil {
			ps.BranchStatuses[i].SubscriptionStatus.ReadyCondition = *readyCondition
			if readyCondition.Status != corev1.ConditionTrue {
				allReady = false
			}
		} else {
			allReady = false
		}

		fs := filterSubscriptions[i]
		ps.BranchStatuses[i].FilterSubscriptionStatus = ParallelSubscriptionStatus{
			Subscription: corev1.ObjectReference{
				APIVersion: fs.APIVersion,
				Kind:       fs.Kind,
				Name:       fs.Name,
				Namespace:  fs.Namespace,
			},
		}
		readyCondition = fs.Status.GetCondition(messagingv1.SubscriptionConditionReady)
		if readyCondition != nil {
			ps.BranchStatuses[i].FilterSubscriptionStatus.ReadyCondition = *readyCondition
			if readyCondition.Status != corev1.ConditionTrue {
				allReady = false
			}
		} else {
			allReady = false
		}

	}
	if allReady {
		pCondSet.Manage(ps).MarkTrue(ParallelConditionSubscriptionsReady)
	} else {
		ps.MarkSubscriptionsNotReady("SubscriptionsNotReady", "Subscriptions are not ready yet, or there are none")
	}
}

// PropagateChannelStatuses sets the ChannelStatuses and ParallelConditionChannelsReady based on the
// status of the incoming channels.
func (ps *ParallelStatus) PropagateChannelStatuses(ingressChannel *duckv1.Channelable, channels []*duckv1.Channelable) {
	if ps.BranchStatuses == nil || len(channels) != len(ps.BranchStatuses) {
		ps.BranchStatuses = make([]ParallelBranchStatus, len(channels))
	}
	allReady := true

	ps.IngressChannelStatus.Channel = corev1.ObjectReference{
		APIVersion: ingressChannel.APIVersion,
		Kind:       ingressChannel.Kind,
		Name:       ingressChannel.Name,
		Namespace:  ingressChannel.Namespace,
	}

	address := ingressChannel.Status.AddressStatus.Address
	if address != nil {
		ps.IngressChannelStatus.ReadyCondition = apis.Condition{Type: apis.ConditionReady, Status: corev1.ConditionTrue}
	} else {
		ps.IngressChannelStatus.ReadyCondition = apis.Condition{Type: apis.ConditionReady, Status: corev1.ConditionFalse, Reason: "NotAddressable", Message: "Channel is not addressable"}
		allReady = false
	}
	ps.setAddress(address)

	for i, c := range channels {
		ps.BranchStatuses[i].FilterChannelStatus = ParallelChannelStatus{
			Channel: corev1.ObjectReference{
				APIVersion: c.APIVersion,
				Kind:       c.Kind,
				Name:       c.Name,
				Namespace:  c.Namespace,
			},
		}
		// TODO: Once the addressable has a real status to dig through, use that here instead of
		// addressable, because it might be addressable but not ready.
		address := c.Status.AddressStatus.Address
		if address != nil {
			ps.BranchStatuses[i].FilterChannelStatus.ReadyCondition = apis.Condition{Type: apis.ConditionReady, Status: corev1.ConditionTrue}
		} else {
			ps.BranchStatuses[i].FilterChannelStatus.ReadyCondition = apis.Condition{Type: apis.ConditionReady, Status: corev1.ConditionFalse, Reason: "NotAddressable", Message: "Channel is not addressable"}
			allReady = false
		}
	}
	if allReady {
		pCondSet.Manage(ps).MarkTrue(ParallelConditionChannelsReady)
	} else {
		ps.MarkChannelsNotReady("ChannelsNotReady", "Channels are not ready yet, or there are none")
	}
}

func (ps *ParallelStatus) MarkChannelsNotReady(reason, messageFormat string, messageA ...interface{}) {
	pCondSet.Manage(ps).MarkFalse(ParallelConditionChannelsReady, reason, messageFormat, messageA...)
}

func (ps *ParallelStatus) MarkSubscriptionsNotReady(reason, messageFormat string, messageA ...interface{}) {
	pCondSet.Manage(ps).MarkFalse(ParallelConditionSubscriptionsReady, reason, messageFormat, messageA...)
}

func (ps *ParallelStatus) MarkAddressableNotReady(reason, messageFormat string, messageA ...interface{}) {
	pCondSet.Manage(ps).MarkFalse(ParallelConditionAddressable, reason, messageFormat, messageA...)
}

func (ps *ParallelStatus) setAddress(address *pkgduckv1.Addressable) {
	ps.Address = address
	if address == nil {
		pCondSet.Manage(ps).MarkFalse(ParallelConditionAddressable, "emptyAddress", "addressable is nil")
	} else {
		pCondSet.Manage(ps).MarkTrue(ParallelConditionAddressable)
	}
}
