/*
Copyright 2023 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 job

import (
	"context"
	"fmt"

	"k8s.io/apimachinery/pkg/util/validation/field"
	"k8s.io/kubernetes/pkg/api/pod"
	"k8s.io/kubernetes/pkg/apis/batch"
	"k8s.io/kubernetes/pkg/apis/core"
	"k8s.io/utils/ptr"
)

const (
	completionsSoftLimit                        = 100_000
	parallelismSoftLimitForUnlimitedCompletions = 10_000
)

// WarningsForJobSpec produces warnings for fields in the JobSpec.
func WarningsForJobSpec(ctx context.Context, path *field.Path, spec, oldSpec *batch.JobSpec) []string {
	var warnings []string
	if spec.CompletionMode != nil && *spec.CompletionMode == batch.IndexedCompletion {
		completions := ptr.Deref(spec.Completions, 0)
		parallelism := ptr.Deref(spec.Parallelism, 0)
		if completions > completionsSoftLimit && parallelism > parallelismSoftLimitForUnlimitedCompletions {
			msg := "In Indexed Jobs with a number of completions higher than 10^5 and a parallelism higher than 10^4, Kubernetes might not be able to track completedIndexes when a big number of indexes fail"
			warnings = append(warnings, fmt.Sprintf("%s: %s", path, msg))
		}
	}
	var oldPodTemplate *core.PodTemplateSpec
	if oldSpec != nil {
		oldPodTemplate = &oldSpec.Template
	}
	warnings = append(warnings, pod.GetWarningsForPodTemplate(ctx, path.Child("template"), &spec.Template, oldPodTemplate)...)
	return warnings
}