reflux/util.go

package reflux

import (
	"reflect"
	"strings"
	"unicode"
)

// DeepClone 深度克隆一个 reflect.Value
func DeepClone(v reflect.Value) reflect.Value {
	// 解引用指针和接口以获取实际值
	for v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface {
		if v.IsNil() {
			return reflect.Value{}
		}
		v = v.Elem()
	}

	if !v.IsValid() {
		return reflect.Value{}
	}

	// 创建新值的指针以便修改
	cloned := reflect.New(v.Type())
	CloneValue(cloned.Elem(), v)
	return cloned
}

// CloneValue 递归克隆值
func CloneValue(dst, src reflect.Value) {
	if !src.IsValid() {
		return
	}

	switch src.Kind() {
	case reflect.Ptr:
		if src.IsNil() {
			return
		}
		dst.Set(reflect.New(src.Type().Elem()))
		CloneValue(dst.Elem(), src.Elem())

	case reflect.Interface:
		if src.IsNil() {
			return
		}
		cloned := DeepClone(src.Elem())
		if cloned.IsValid() {
			dst.Set(cloned)
		}

	case reflect.Struct:
		for i := 0; i < src.NumField(); i++ {
			if dst.Field(i).CanSet() {
				CloneValue(dst.Field(i), src.Field(i))
			}
		}

	case reflect.Slice:
		if src.IsNil() {
			return
		}
		dst.Set(reflect.MakeSlice(src.Type(), src.Len(), src.Cap()))
		cloneSequence(dst, src)

	case reflect.Array:
		cloneSequence(dst, src)

	case reflect.Map:
		if src.IsNil() {
			return
		}
		dst.Set(reflect.MakeMap(src.Type()))
		for _, key := range src.MapKeys() {
			val := src.MapIndex(key)
			clonedVal := cloneElement(val)
			dst.SetMapIndex(key, clonedVal)
		}

	default:
		// 对于基本类型(int, string, bool, float等),直接赋值
		if dst.CanSet() {
			dst.Set(src)
		}
	}
}

// cloneSequence 克隆序列类型(slice/array)的元素
func cloneSequence(dst, src reflect.Value) {
	for i := 0; i < src.Len(); i++ {
		elem := src.Index(i)
		clonedElem := cloneElement(elem)
		dst.Index(i).Set(clonedElem)
	}
}

// cloneElement 克隆单个元素,处理 interface 包装的情况
// 对于复杂类型(struct, map, slice, array)进行深度克隆
// 对于基本类型,直接返回原始值
func cloneElement(elem reflect.Value) reflect.Value {
	// 解引用以获取实际值
	actualElem := elem
	for actualElem.Kind() == reflect.Interface || actualElem.Kind() == reflect.Ptr {
		if actualElem.IsNil() {
			return elem
		}
		actualElem = actualElem.Elem()
	}

	// 如果元素需要递归克隆(struct, map, slice, array)
	if actualElem.IsValid() && needsDeepClone(actualElem.Kind()) {
		clonedElem := reflect.New(actualElem.Type()).Elem()
		CloneValue(clonedElem, actualElem)
		return clonedElem
	}

	// 对于基本类型,直接返回原始值
	return elem
}

// needsDeepClone 判断某个类型是否需要深度克隆
func needsDeepClone(kind reflect.Kind) bool {
	return kind == reflect.Struct ||
		kind == reflect.Map ||
		kind == reflect.Slice ||
		kind == reflect.Array
}

// expandPath 展开路径,支持点号分割
// 例如: expandPath("a.b", "c") -> []string{"a", "b", "c"}
func expandPath(p ...string) []string {
	var result []string
	for _, segment := range p {
		// 按点号分割
		parts := strings.Split(segment, ".")
		for _, part := range parts {
			if part != "" { // 忽略空字符串
				result = append(result, part)
			}
		}
	}
	return result
}

// capitalizeFirst 将字符串首字母转换为大写
// 用于处理 struct 字段名,使其符合 Go 的公开字段命名规范
func capitalizeFirst(s string) string {
	if s == "" {
		return s
	}
	runes := []rune(s)
	runes[0] = unicode.ToUpper(runes[0])
	return string(runes)
}

// tryStructField 尝试获取 struct 字段,支持小写字段名自动转大写
// 1. 首先尝试原始字段名
// 2. 如果失败且首字母是小写,尝试首字母大写的版本
func tryStructField(v reflect.Value, fieldName string) reflect.Value {
	// 首先尝试原始字段名
	field := v.FieldByName(fieldName)
	if field.IsValid() {
		return field
	}

	// 如果字段名首字母是小写,尝试首字母大写
	if len(fieldName) > 0 && unicode.IsLower(rune(fieldName[0])) {
		capitalizedName := capitalizeFirst(fieldName)
		field = v.FieldByName(capitalizedName)
		if field.IsValid() {
			return field
		}
	}

	return reflect.Value{}
}