config/utils.go

/*
 * Copyright (C) 2017 eschao <esc.chao@gmail.com>
 *
 * 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 config

import (
	"encoding"
	"fmt"
	"reflect"
	"strconv"
	"strings"
	"time"
)

func setValueWithBool(value reflect.Value, boolStr string) error {
	boolValue, err := strconv.ParseBool(boolStr)
	if err != nil {
		if txt, ok := value.Interface().(encoding.TextUnmarshaler); ok {
			if err = txt.UnmarshalText([]byte(boolStr)); err == nil {
				return nil
			}
		}
	}

	if err != nil {
		return fmt.Errorf("parse bool: %w", err)
	}

	value.SetBool(boolValue)

	return nil
}

func setValueWithDuration(value reflect.Value, str string) error {
	d, err := time.ParseDuration(str)
	if err != nil {
		return fmt.Errorf("parse duration: %w", err)
	}

	value.Set(reflect.ValueOf(d))

	return nil
}

func setValueWithFloatX(value reflect.Value, floatStr string, bitSize int) error {
	floatValue, err := strconv.ParseFloat(floatStr, bitSize)
	if err != nil {
		return fmt.Errorf("parse float: %w", err)
	}

	value.SetFloat(floatValue)

	return nil
}

func setValueWithIntX(value reflect.Value, intStr string, bitSize int) error {
	intValue, err := strconv.ParseInt(intStr, 10, bitSize)
	if err != nil {
		if txt, ok := value.Interface().(encoding.TextUnmarshaler); ok {
			if err = txt.UnmarshalText([]byte(intStr)); err == nil {
				return nil
			}
		}
	}

	if err != nil {
		return fmt.Errorf("parse int: %w", err)
	}

	value.SetInt(intValue)

	return nil
}

func setValueWithUintX(value reflect.Value, uintStr string, bitSize int) error {
	uintValue, err := strconv.ParseUint(uintStr, 10, bitSize)
	if err != nil {
		if txt, ok := value.Interface().(encoding.TextUnmarshaler); ok {
			if err = txt.UnmarshalText([]byte(uintStr)); err == nil {
				return nil
			}
		}
	}

	if err != nil {
		return fmt.Errorf("parse uint: %w", err)
	}

	value.SetUint(uintValue)

	return nil
}

func setValueWithSlice(value reflect.Value, slice string, sep string) error {
	data := strings.Split(slice, sep)

	size := len(data)
	if size > 0 {
		slice := reflect.MakeSlice(value.Type(), size, size)

		for index := range size {
			ele := slice.Index(index)
			str := data[index]

			if ok, err := setDurationValue(ele, str); ok {
				return err
			}

			if setUnmarshalTextValue(ele, str) {
				continue
			}

			var err error

			kind := ele.Kind()
			switch kind {
			case reflect.Bool:
				err = setValueWithBool(ele, str)
			case reflect.String:
				ele.SetString(str)
			case reflect.Uint8:
				err = setValueWithUintX(ele, str, Uint8Size)
			case reflect.Uint16:
				err = setValueWithUintX(ele, str, Uint16Size)
			case reflect.Uint, reflect.Uint32:
				err = setValueWithUintX(ele, str, Uint32Size)
			case reflect.Uint64:
				err = setValueWithUintX(ele, str, Uint64Size)
			case reflect.Int8:
				err = setValueWithIntX(ele, str, Int8Size)
			case reflect.Int16:
				err = setValueWithIntX(ele, str, Int16Size)
			case reflect.Int, reflect.Int32:
				err = setValueWithIntX(ele, str, Int32Size)
			case reflect.Int64:
				err = setValueWithIntX(ele, str, Int64Size)
			case reflect.Float32:
				err = setValueWithFloatX(ele, str, Float32Size)
			case reflect.Float64:
				err = setValueWithFloatX(ele, str, Float64Size)
			default:
				return fmt.Errorf("%w: %s", errUnsupportedType, kind.String())
			}

			if err != nil {
				return err
			}
		}

		value.Set(slice)
	}

	return nil
}

func setUnmarshalTextValue(value reflect.Value, str string) bool {
	unmarshalerType := reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
	valuePtr := reflect.New(value.Type())

	if valuePtr.Type().Implements(unmarshalerType) {
		if decoder, ok := valuePtr.Interface().(encoding.TextUnmarshaler); ok {
			if err := decoder.UnmarshalText([]byte(str)); err != nil {
				return false
			}

			value.Set(valuePtr.Elem())

			return true
		}
	}

	return false
}

func setDurationValue(value reflect.Value, str string) (bool, error) {
	valueTypePkgPath := value.Type().PkgPath()
	valueTypeName := value.Type().Name()

	if valueTypePkgPath == "time" && valueTypeName == "Duration" {
		return true, setValueWithDuration(value, str)
	}

	return false, nil
}