// 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 revision

import (
	metav1beta1 "k8s.io/apimachinery/pkg/apis/meta/v1beta1"
	"k8s.io/apimachinery/pkg/runtime"
	"knative.dev/serving/pkg/apis/serving"
	servingv1 "knative.dev/serving/pkg/apis/serving/v1"

	"knative.dev/client/pkg/kn/commands"
	hprinters "knative.dev/client/pkg/printers"
)

const (
	RevisionTrafficAnnotation = "client.knative.dev/traffic"
	RevisionTagsAnnotation    = "client.knative.dev/tags"
)

// Max column size
const ListColumnMaxLength = 50

// RevisionListHandlers adds print handlers for revision list command
func RevisionListHandlers(h hprinters.PrintHandler) {
	RevisionColumnDefinitions := []metav1beta1.TableColumnDefinition{
		{Name: "Namespace", Type: "string", Description: "Namespace of the Knative service", Priority: 0},
		{Name: "Name", Type: "string", Description: "Name of the revision.", Priority: 1},
		{Name: "Service", Type: "string", Description: "Name of the Knative service.", Priority: 1},
		{Name: "Traffic", Type: "string", Description: "Percentage of traffic assigned to this revision.", Priority: 1},
		{Name: "Tags", Type: "string", Description: "Set of tags assigned to this revision.", Priority: 1},
		{Name: "Generation", Type: "string", Description: "Generation of the revision", Priority: 1},
		{Name: "Age", Type: "string", Description: "Age of the revision.", Priority: 1},
		{Name: "Conditions", Type: "string", Description: "Conditions describing statuses of the revision.", Priority: 1},
		{Name: "Ready", Type: "string", Description: "Ready condition status of the revision.", Priority: 1},
		{Name: "Reason", Type: "string", Description: "Reason for non-ready condition of the revision.", Priority: 1},
	}
	h.TableHandler(RevisionColumnDefinitions, printRevision)
	h.TableHandler(RevisionColumnDefinitions, printRevisionList)
}

// Private functions

// printRevisionList populates the Knative revision list table rows
func printRevisionList(revisionList *servingv1.RevisionList, options hprinters.PrintOptions) ([]metav1beta1.TableRow, error) {

	rows := make([]metav1beta1.TableRow, 0, len(revisionList.Items))
	for _, rev := range revisionList.Items {
		r, err := printRevision(&rev, options)
		if err != nil {
			return nil, err
		}
		rows = append(rows, r...)
	}
	return rows, nil
}

// printRevision populates the Knative revision table rows
func printRevision(revision *servingv1.Revision, options hprinters.PrintOptions) ([]metav1beta1.TableRow, error) {
	name := revision.Name
	service := revision.Labels[serving.ServiceLabelKey]
	traffic := revision.Annotations[RevisionTrafficAnnotation]
	tags := revision.Annotations[RevisionTagsAnnotation]
	generation := revision.Labels[serving.ConfigurationGenerationLabelKey]
	age := commands.TranslateTimestampSince(revision.CreationTimestamp)
	conditions := commands.ConditionsValue(revision.Status.Conditions)
	ready := commands.ReadyCondition(revision.Status.Conditions)
	reason := commands.NonReadyConditionReason(revision.Status.Conditions)
	row := metav1beta1.TableRow{
		Object: runtime.RawExtension{Object: revision},
	}

	// Namespace is first column for "-A"
	if options.AllNamespaces {
		row.Cells = append(row.Cells, trunc(revision.Namespace))
	}

	row.Cells = append(row.Cells,
		trunc(name),
		trunc(service),
		trunc(traffic),
		trunc(tags),
		trunc(generation),
		trunc(age),
		trunc(conditions),
		trunc(ready),
		trunc(reason))
	return []metav1beta1.TableRow{row}, nil
}

func trunc(txt string) string {
	if len(txt) <= ListColumnMaxLength {
		return txt
	}
	return txt[:ListColumnMaxLength-4] + " ..."
}