/*
 * Copyright (C) @2021 Webank Group Holding Limited
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 common

import (
	"fmt"

	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/cli-runtime/pkg/genericclioptions"
)

const (
	// LoadBalancerWidth is the width how we describe load balancer
	LoadBalancerWidth = 16

	// LabelNodeRolePrefix is a label prefix for node roles
	// It's copied over to here until it's merged in core: https://github.com/kubernetes/kubernetes/pull/39112
	LabelNodeRolePrefix = "node-role.kubernetes.io/"

	// NodeLabelRole specifies the role of a node
	NodeLabelRole = "kubernetes.io/role"
)

// DescriberFunc gives a way to display the specified RESTMapping type
type DescriberFunc func(restClientGetter genericclioptions.RESTClientGetter, mapping *meta.RESTMapping) (Describer, error)

// Describer generates output for the named resource or an error
// if the output could not be generated. Implementers typically
// abstract the retrieval of the named object from a remote server.
type Describer interface {
	Describe(namespace, name string, describerSettings DescriberSettings) (output string, err error)
}

// DescriberSettings holds display configuration for each object
// describer to control what is printed.
type DescriberSettings struct {
	ShowEvents bool
}

// ObjectDescriber is an interface for displaying arbitrary objects with extra
// information. Use when an object is in hand (on disk, or already retrieved).
// Implementers may ignore the additional information passed on extra, or use it
// by default. ObjectDescribers may return ErrNoDescriber if no suitable describer
// is found.
type ObjectDescriber interface {
	DescribeObject(object interface{}, extra ...interface{}) (output string, err error)
}

// ErrNoDescriber is a structured error indicating the provided object or objects
// cannot be described.
type ErrNoDescriber struct {
	Types []string
}

// Error implements the error interface.
func (e ErrNoDescriber) Error() string {
	return fmt.Sprintf("no describer has been defined for %v", e.Types)
}
