/*
Copyright 2017 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 errors

import (
	"fmt"
)

// AutoscalerErrorType describes a high-level category of a given error
type AutoscalerErrorType string

// AutoscalerError contains information about Autoscaler errors
type AutoscalerError struct {
	errorType AutoscalerErrorType
	msg       string
}

const (
	// CloudProviderError is an error related to underlying infrastructure
	CloudProviderError AutoscalerErrorType = "cloudProviderError"
	// ApiCallError is an error related to communication with k8s API server
	ApiCallError AutoscalerErrorType = "apiCallError"
	// InternalError is an error inside Cluster Autoscaler
	InternalError AutoscalerErrorType = "internalError"
	// TransientError is an error that causes us to skip a single loop, but
	// does not require any additional action.
	TransientError AutoscalerErrorType = "transientError"
)

// NewAutoscalerError returns new autoscaler error with a message constructed from format string
func NewAutoscalerError(errorType AutoscalerErrorType, msg string, args ...interface{}) *AutoscalerError {
	return &AutoscalerError{
		errorType: errorType,
		msg:       fmt.Sprintf(msg, args...),
	}
}

// ToAutoscalerError converts an error to AutoscalerError with given type,
// unless it already is an AutoscalerError (in which case it's not modified).
func ToAutoscalerError(defaultType AutoscalerErrorType, err error) *AutoscalerError {
	if e, ok := err.(*AutoscalerError); ok {
		return e
	}
	return NewAutoscalerError(defaultType, err.Error())
}

// Error implements golang error interface
func (e *AutoscalerError) Error() string {
	return e.msg
}

// Type returns the typ of AutoscalerError
func (e *AutoscalerError) Type() AutoscalerErrorType {
	return e.errorType
}