conversion.go

/*
 Copyright 2020 Padduck, LLC
  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 pufferpanel

import (
	"errors"
	"fmt"
	"github.com/spf13/cast"
	"reflect"
	"time"
)

//Converts the val parameter to the same type as the target
func Convert(val interface{}, target interface{}) (interface{}, error) {
	switch target.(type) {
	case string:
		if val == nil {
			return "", nil
		}
		return cast.ToStringE(val)
	case int:
		if val == nil {
			return int(0), nil
		}
		return cast.ToIntE(val)
	case int8:
		if val == nil {
			return int8(0), nil
		}
		return cast.ToInt8E(val)
	case int16:
		if val == nil {
			return int16(0), nil
		}
		return cast.ToInt16E(val)
	case int32:
		if val == nil {
			return int32(0), nil
		}
		return cast.ToInt32E(val)
	case int64:
		if val == nil {
			return int64(0), nil
		}
		return cast.ToInt64E(val)
	case uint:
		if val == nil {
			return uint(0), nil
		}
		return cast.ToUintE(val)
	case uint8:
		if val == nil {
			return uint8(0), nil
		}
		return cast.ToUint8E(val)
	case uint16:
		if val == nil {
			return uint16(0), nil
		}
		return cast.ToUint16E(val)
	case uint32:
		if val == nil {
			return uint32(0), nil
		}
		return cast.ToUint32E(val)
	case uint64:
		if val == nil {
			return uint64(0), nil
		}
		return cast.ToUint64E(val)
	case bool:
		if val == nil {
			return false, nil
		}
		return cast.ToBoolE(val)
	case time.Duration:
		if val == nil {
			return time.Duration(0), nil
		}
		return cast.ToDurationE(val)
	case time.Time:
		if val == nil {
			return time.Time{}, nil
		}
		return cast.ToTimeE(val)
	case float32:
		if val == nil {
			return float32(0), nil
		}
		return cast.ToFloat64E(val)
	case float64:
		if val == nil {
			return float64(0), nil
		}
		return cast.ToFloat64E(val)
	case map[string]string:
		if val == nil {
			return map[string]string{}, nil
		}
		return cast.ToStringMapStringE(val)
	case map[string][]string:
		if val == nil {
			return map[string][]string{}, nil
		}
		return cast.ToStringMapStringSliceE(val)
	case map[string]bool:
		if val == nil {
			return map[string]bool{}, nil
		}
		return cast.ToStringMapBoolE(val)
	case map[string]interface{}:
		if val == nil {
			return map[string]interface{}{}, nil
		}
		return cast.ToStringMapE(val)
	case map[string]int:
		if val == nil {
			return map[string]int{}, nil
		}
		return cast.ToStringMapIntE(val)
	case map[string]int64:
		if val == nil {
			return map[string]int64{}, nil
		}
		return cast.ToStringMapInt64E(val)
	case []interface{}:
		if val == nil {
			return []interface{}{}, nil
		}
		return cast.ToSliceE(val)
	case []bool:
		if val == nil {
			return []bool{}, nil
		}
		return cast.ToBoolSliceE(val)
	case []string:
		if val == nil {
			return []string{}, nil
		}
		return cast.ToStringSliceE(val)
	case []int:
		if val == nil {
			return []int{}, nil
		}
		return cast.ToIntSliceE(val)
	case []time.Duration:
		if val == nil {
			return []time.Duration{}, nil
		}
		return cast.ToDurationSliceE(val)
	}

	return nil, errors.New(fmt.Sprintf("cannot convert %s to %s", reflect.TypeOf(val), reflect.TypeOf(target)))
}