handle dimension

internal/entity/dimension.go

@@ -0,0 +1,142 @@
+package entity
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+var DefaultLocale = DimensionLocalRU
+
+type DimensionLocale uint8
+
+const (
+	DimensionLocalUnspecified DimensionLocale = iota
+	DimensionLocalRU
+
+	dimensionLocalEnd
+)
+
+type DimensionKind uint8
+
+func (k DimensionKind) GetPos() float64 {
+	switch k {
+	case DimensionKindMilimeter:
+		return 1
+	case DimensionKindCentimeter:
+		return 10
+	case DimensionKindMeter:
+		return 1000
+	default:
+		return 0
+	}
+}
+
+func (k DimensionKind) String() string {
+	m := getLocaleKindToStringMap()[DefaultLocale]
+	return m[k]
+}
+
+const (
+	DimensionKindUnspecified DimensionKind = iota
+	DimensionKindMilimeter
+	DimensionKindCentimeter
+	DimensionKindMeter
+)
+
+type Dimension struct {
+	Value float64
+	Kind  DimensionKind
+}
+
+func (d Dimension) MarshalText() ([]byte, error) {
+	value := strconv.FormatFloat(d.Value, 'f', 4, 64) + " " + d.Kind.String()
+	return []byte(value), nil
+}
+
+func (d *Dimension) UnmarshalText(data []byte) (err error) {
+	*d, err = ParseDimention(string(data), DefaultLocale)
+	return err
+}
+
+func (d Dimension) AdjustTo(kind DimensionKind) Dimension {
+	from := d.Kind.GetPos()
+	to := kind.GetPos()
+
+	switch {
+	case from < to:
+		mult := to / from
+		return Dimension{
+			Kind:  kind,
+			Value: d.Value / float64(mult),
+		}
+	case from > to:
+		mult := from / to
+		return Dimension{
+			Kind:  kind,
+			Value: d.Value * float64(mult),
+		}
+	}
+
+	return d
+}
+
+func ParseDimention(value string, locale DimensionLocale) (Dimension, error) {
+	switch locale {
+	case DimensionLocalRU:
+	default:
+		return Dimension{}, SimpleError("unknown locale for parse")
+	}
+
+	dimensionStrToKind := getLocaleToKindMap()[locale]
+	lastSpaceIdx := strings.LastIndex(value, " ")
+	if lastSpaceIdx == -1 {
+		return Dimension{}, SimpleError("expected 2 values after split for value " + value)
+	}
+
+	var splitted [2]string
+	splitted[0] = strings.ReplaceAll(value[:lastSpaceIdx], " ", "")
+	splitted[1] = value[lastSpaceIdx+1:]
+
+	var out Dimension
+	var ok bool
+	out.Kind, ok = dimensionStrToKind[splitted[1]]
+	if !ok {
+		return Dimension{}, SimpleError("dimension map not found for kind " + splitted[1])
+	}
+
+	var err error
+	out.Value, err = strconv.ParseFloat(splitted[0], 64)
+	if err != nil {
+		return Dimension{}, fmt.Errorf("parsing value: %w", err)
+	}
+
+	return out, nil
+}
+
+func NewMilimeterDimension(value float64) Dimension {
+	return Dimension{
+		Value: value,
+		Kind:  DimensionKindMilimeter,
+	}
+}
+
+func getLocaleToKindMap() map[DimensionLocale]map[string]DimensionKind {
+	return map[DimensionLocale]map[string]DimensionKind{
+		DimensionLocalRU: {
+			"мм": DimensionKindMilimeter,
+			"см": DimensionKindCentimeter,
+			"м":  DimensionKindMeter,
+		},
+	}
+}
+
+func getLocaleKindToStringMap() map[DimensionLocale]map[DimensionKind]string {
+	return map[DimensionLocale]map[DimensionKind]string{
+		DimensionLocalRU: {
+			DimensionKindMilimeter:  "мм",
+			DimensionKindCentimeter: "см",
+			DimensionKindMeter:      "м",
+		},
+	}
+}