package encoding

import "reflect"

func getTypeKind(t reflect.Type) reflect.Kind {
	kind := t.Kind()

	switch {
	case kind >= reflect.Int && kind <= reflect.Int64:
		return reflect.Int
	case kind >= reflect.Uint && kind <= reflect.Uint64:
		return reflect.Uint
	case kind >= reflect.Float32 && kind <= reflect.Float64:
		return reflect.Float32
	default:
		return kind
	}
}

func isEmptyValue(v reflect.Value) bool {
	switch v.Kind() {
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
		return v.Len() == 0
	case reflect.Bool:
		return !v.Bool()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Interface, reflect.Ptr:
		return v.IsNil()
	}
	return false
}

func fieldByIndex(v reflect.Value, index []int) reflect.Value {
	for _, i := range index {
		if v.Kind() == reflect.Ptr {
			if v.IsNil() {
				v.Set(reflect.New(v.Type().Elem()))
			}
			v = v.Elem()
		}
		v = v.Field(i)
	}

	return v
}

func typeByIndex(t reflect.Type, index []int) reflect.Type {
	for _, i := range index {
		if t.Kind() == reflect.Ptr {
			t = t.Elem()
		}
		t = t.Field(i).Type
	}
	return t
}

// valueByString sorts reflect.Value by the string value, this is useful for
// sorting the result of MapKeys
type valueByString []reflect.Value

func (x valueByString) Len() int { return len(x) }

func (x valueByString) Swap(i, j int) { x[i], x[j] = x[j], x[i] }

func (x valueByString) Less(i, j int) bool {
	return x[i].String() < x[j].String()
}