// Copyright 2022-2023 The sacloud/packages-go 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 objutil

import (
	"reflect"
)

// IsEmpty is copied from github.com/stretchr/testify/assert/assertions.go
func IsEmpty(object interface{}) bool {
	// get nil case out of the way
	if object == nil {
		return true
	}

	objValue := reflect.ValueOf(object)

	switch objValue.Kind() {
	// collection types are empty when they have no element
	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
		return objValue.Len() == 0
	// pointers are empty if nil or if the value they point to is empty
	case reflect.Ptr:
		if objValue.IsNil() {
			return true
		}
		deref := objValue.Elem().Interface()
		return IsEmpty(deref)
	// for all other types, compare against the zero value
	default:
		zero := reflect.Zero(objValue.Type())
		return reflect.DeepEqual(object, zero.Interface())
	}
}