package codec

import (
	"reflect"
	"strconv"
	"strings"

	"github.com/bytedance/sonic"
	"github.com/go-viper/mapstructure/v2"
)

func MapDecode(input, output any) (err error) {
	decoder, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
		Result:           output,
		WeaklyTypedInput: true, // 开启弱类型转换
		DecodeHook:       mapstructure.ComposeDecodeHookFunc(StringToNumberHook()),
	})
	if err != nil {
		return
	}
	err = decoder.Decode(input)
	return
}

// 方案1：最推荐 - 字符串 → 数字（int/uint/float）全覆盖
func StringToNumberHook() mapstructure.DecodeHookFunc {
	return mapstructure.DecodeHookFuncType(func(from reflect.Type, to reflect.Type, data interface{}) (interface{}, error) {
		if from.Kind() == reflect.String {
			str := data.(string)
			str = strings.TrimSpace(str)
			switch to.Kind() {
			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
				return strconv.ParseInt(str, 10, 64)
			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
				return strconv.ParseUint(str, 10, 64)
			case reflect.Float32, reflect.Float64:
				return strconv.ParseFloat(str, 64)
			}

			// string to []float64, [][]float64
			if to.Kind() == reflect.Slice {
				switch to {
				case reflect.SliceOf(reflect.TypeOf(float64(0.0))):
					var v []float64
					if err := sonic.UnmarshalString(str, &v); err == nil {
						return v, nil
					}
				case reflect.SliceOf(reflect.SliceOf(reflect.TypeOf(float64(0.0)))):
					var v [][]float64
					if err := sonic.UnmarshalString(str, &v); err == nil {
						return v, nil
					}
				}
			}
		}
		return data, nil
	})
}