package structx

import (
	"encoding/json"
	"fmt"
	"reflect"
	"strconv"

	"code.yun.ink/pkg/convx"
)

// converterFunc 类型转换函数
type converterFunc func(reflect.Value, string) (interface{}, error)

var (
	typeConverters = map[reflect.Kind]converterFunc{
		reflect.Bool:    convertBool,
		reflect.Int:     convertInt[int],
		reflect.Int8:    convertInt[int8],
		reflect.Int16:   convertInt[int16],
		reflect.Int32:   convertInt[int32],
		reflect.Int64:   convertInt[int64],
		reflect.Uint:    convertUint[uint],
		reflect.Uint8:   convertUint[uint8],
		reflect.Uint16:  convertUint[uint16],
		reflect.Uint32:  convertUint[uint32],
		reflect.Uint64:  convertUint[uint64],
		reflect.Float32: convertFloat[float32],
		reflect.Float64: convertFloat[float64],
		reflect.String:  convertString,
		reflect.Slice:   convertSlice,
		reflect.Array:   convertArray,
		reflect.Map:     convertMap,
	}
)

// 转换为字符串
func convertToString(item interface{}) string {
	if str, ok := item.(string); ok {
		return str
	}
	return fmt.Sprintf("%v", item)
}

// 转换为数字（float64）
func convertToFloat64(item interface{}) (float64, error) {
	switch v := item.(type) {
	case float64:
		return v, nil
	case int, int32, int64:
		return float64(reflect.ValueOf(v).Int()), nil
	case uint, uint32, uint64:
		return float64(reflect.ValueOf(v).Uint()), nil
	case float32:
		return float64(v), nil
	default:
		return 0, fmt.Errorf("无法转换为数字")
	}
}

// 转换为类型别名
func convertToTypeAlias(aliasType reflect.Type, value interface{}) (interface{}, error) {
	if aliasType.Kind() == reflect.Ptr {
		elemType := aliasType.Elem()
		newValue := reflect.New(elemType)
		elemValue := newValue.Elem()

		converted, err := convertValueToType(value, elemType)
		if err != nil {
			return nil, err
		}
		elemValue.Set(reflect.ValueOf(converted))
		return newValue.Interface(), nil
	}

	return convertValueToType(value, aliasType)
}

// 转换值为目标类型
func convertValueToType(value interface{}, targetType reflect.Type) (interface{}, error) {
	valueType := reflect.TypeOf(value)
	if valueType.AssignableTo(targetType) {
		return value, nil
	}
	if valueType.ConvertibleTo(targetType) {
		return reflect.ValueOf(value).Convert(targetType).Interface(), nil
	}
	return nil, fmt.Errorf("无法转换类型")
}

// 类型转换函数
func convertBool(field reflect.Value, value string) (interface{}, error) {
	return convx.ToBool(value)
}

func convertInt[T int | int8 | int16 | int32 | int64](field reflect.Value, value string) (interface{}, error) {
	bits := field.Type().Bits()
	intVal, err := strconv.ParseInt(value, 10, bits)
	if err != nil {
		return nil, err
	}
	return T(intVal), nil
}

func convertUint[T uint | uint8 | uint16 | uint32 | uint64](field reflect.Value, value string) (interface{}, error) {
	bits := field.Type().Bits()
	uintVal, err := strconv.ParseUint(value, 10, bits)
	if err != nil {
		return nil, err
	}
	return T(uintVal), nil
}

func convertFloat[T float32 | float64](field reflect.Value, value string) (interface{}, error) {
	bits := field.Type().Bits()
	floatVal, err := strconv.ParseFloat(value, bits)
	if err != nil {
		return nil, err
	}
	return T(floatVal), nil
}

func convertString(field reflect.Value, value string) (interface{}, error) {
	return value, nil
}

func convertSlice(field reflect.Value, value string) (interface{}, error) {
	var result []interface{}
	if err := json.Unmarshal([]byte(value), &result); err != nil {
		return nil, err
	}
	return result, nil
}

func convertArray(field reflect.Value, value string) (interface{}, error) {
	var result []interface{}
	if err := json.Unmarshal([]byte(value), &result); err != nil {
		return nil, err
	}
	return result, nil
}

func convertMap(field reflect.Value, value string) (interface{}, error) {
	return nil, fmt.Errorf("map转换未实现")
}

func getBaseTypeFromAlias(aliasType reflect.Type) reflect.Type {
	if aliasType.Kind() == reflect.Ptr {
		aliasType = aliasType.Elem()
	}

	switch aliasType.Kind() {
	case reflect.String:
		return reflect.TypeOf("")
	case reflect.Int:
		return reflect.TypeOf(int(0))
	case reflect.Int8:
		return reflect.TypeOf(int8(0))
	case reflect.Int16:
		return reflect.TypeOf(int16(0))
	case reflect.Int32:
		return reflect.TypeOf(int32(0))
	case reflect.Int64:
		return reflect.TypeOf(int64(0))
	case reflect.Uint:
		return reflect.TypeOf(uint(0))
	case reflect.Uint8:
		return reflect.TypeOf(uint8(0))
	case reflect.Uint16:
		return reflect.TypeOf(uint16(0))
	case reflect.Uint32:
		return reflect.TypeOf(uint32(0))
	case reflect.Uint64:
		return reflect.TypeOf(uint64(0))
	case reflect.Float32:
		return reflect.TypeOf(float32(0))
	case reflect.Float64:
		return reflect.TypeOf(float64(0))
	case reflect.Bool:
		return reflect.TypeOf(false)
	default:
		return nil
	}
}