/*
Copyright (c) 2022-2024 Tigera, Inc. All rights reserved.

Copyright 2014 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.

The contents of this file are mostly copied, with minor modifications, from:
https://github.com/kubernetes/kubernetes/blob/f38615fb9d1188934213633ff92d523259ae8f6a/pkg/apis/core/v1/helper/helpers.go
*/
package v1helper

import (
	"fmt"
	"strings"

	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/selection"
	"k8s.io/apimachinery/pkg/util/validation"
)

// IsExtendedResourceName returns true if:
// 1. the resource name is not in the default namespace;
// 2. resource name does not have "requests." prefix,
// to avoid confusion with the convention in quota
// 3. it satisfies the rules in IsQualifiedName() after converted into quota resource name
func IsExtendedResourceName(name v1.ResourceName) bool {
	if IsNativeResource(name) || strings.HasPrefix(string(name), v1.DefaultResourceRequestsPrefix) {
		return false
	}
	// Ensure it satisfies the rules in IsQualifiedName() after converted into quota resource name
	nameForQuota := fmt.Sprintf("%s%s", v1.DefaultResourceRequestsPrefix, string(name))
	if errs := validation.IsQualifiedName(string(nameForQuota)); len(errs) != 0 {
		return false
	}
	return true
}

// IsPrefixedNativeResource returns true if the resource name is in the
// *kubernetes.io/ namespace.
func IsPrefixedNativeResource(name v1.ResourceName) bool {
	return strings.Contains(string(name), v1.ResourceDefaultNamespacePrefix)
}

// IsNativeResource returns true if the resource name is in the
// *kubernetes.io/ namespace. Partially-qualified (unprefixed) names are
// implicitly in the kubernetes.io/ namespace.
func IsNativeResource(name v1.ResourceName) bool {
	return !strings.Contains(string(name), "/") ||
		IsPrefixedNativeResource(name)
}

// IsHugePageResourceName returns true if the resource name has the huge page
// resource prefix.
func IsHugePageResourceName(name v1.ResourceName) bool {
	return strings.HasPrefix(string(name), v1.ResourceHugePagesPrefix)
}

// HugePageResourceName returns a ResourceName with the canonical hugepage
// prefix prepended for the specified page size.  The page size is converted
// to its canonical representation.
func HugePageResourceName(pageSize resource.Quantity) v1.ResourceName {
	return v1.ResourceName(fmt.Sprintf("%s%s", v1.ResourceHugePagesPrefix, pageSize.String()))
}

// IsHugePageMedium returns true if the volume medium is in 'HugePages[-size]' format
func IsHugePageMedium(medium v1.StorageMedium) bool {
	if medium == v1.StorageMediumHugePages {
		return true
	}
	return strings.HasPrefix(string(medium), string(v1.StorageMediumHugePagesPrefix))
}

// IsOvercommitAllowed returns true if the resource is in the default
// namespace and is not hugepages.
func IsOvercommitAllowed(name v1.ResourceName) bool {
	return IsNativeResource(name) &&
		!IsHugePageResourceName(name)
}

func ContainsAccessMode(modes []v1.PersistentVolumeAccessMode, mode v1.PersistentVolumeAccessMode) bool {
	for _, m := range modes {
		if m == mode {
			return true
		}
	}
	return false
}

// TopologySelectorRequirementsAsSelector converts the []TopologySelectorLabelRequirement api type into a struct
// that implements labels.Selector.
func TopologySelectorRequirementsAsSelector(tsm []v1.TopologySelectorLabelRequirement) (labels.Selector, error) {
	if len(tsm) == 0 {
		return labels.Nothing(), nil
	}

	selector := labels.NewSelector()
	for _, expr := range tsm {
		r, err := labels.NewRequirement(expr.Key, selection.In, expr.Values)
		if err != nil {
			return nil, err
		}
		selector = selector.Add(*r)
	}

	return selector, nil
}