feat(i18n): add count support to translation context

Co-Authored-By: Virgil <virgil@lethean.io>

context.go

@@ -1,5 +1,7 @@
 package i18n
 
+import "dappco.re/go/core"
+
 // TranslationContext provides disambiguation for translations.
 //
 //	T("direction.right", C("navigation")) // "rechts" (German)
@@ -9,12 +11,14 @@ type TranslationContext struct {
 	Gender    string
 	Location  string
 	Formality Formality
+	count     int
+	countSet  bool
 	Extra     map[string]any
 }
 
 // C creates a TranslationContext.
 func C(context string) *TranslationContext {
-	return &TranslationContext{Context: context}
+	return &TranslationContext{Context: context, count: 1}
 }
 
 func (c *TranslationContext) WithGender(gender string) *TranslationContext {
@@ -57,6 +61,16 @@ func (c *TranslationContext) WithFormality(f Formality) *TranslationContext {
 	return c
 }
 
+// Count sets the count used for plural-sensitive translations.
+func (c *TranslationContext) Count(n int) *TranslationContext {
+	if c == nil {
+		return nil
+	}
+	c.count = n
+	c.countSet = true
+	return c
+}
+
 func (c *TranslationContext) Set(key string, value any) *TranslationContext {
 	if c == nil {
 		return nil
@@ -109,3 +123,31 @@ func (c *TranslationContext) FormalityValue() Formality {
 	}
 	return c.Formality
 }
+
+// CountInt returns the current count value.
+func (c *TranslationContext) CountInt() int {
+	if c == nil {
+		return 1
+	}
+	return c.count
+}
+
+// CountString returns the current count value formatted as text.
+func (c *TranslationContext) CountString() string {
+	if c == nil {
+		return "1"
+	}
+	return core.Sprintf("%d", c.count)
+}
+
+// IsPlural reports whether the count is plural.
+func (c *TranslationContext) IsPlural() bool {
+	return c != nil && c.count != 1
+}
+
+func (c *TranslationContext) countValue() (int, bool) {
+	if c == nil {
+		return 1, false
+	}
+	return c.count, c.countSet
+}

context_map.go

@@ -47,7 +47,7 @@ func contextMapValuesAny(values map[string]any) map[string]any {
 	extra := make(map[string]any, len(values))
 	for key, value := range values {
 		switch key {
-		case "Context", "Gender", "Location", "Formality":
+		case "Context", "Gender", "Location", "Formality", "Count", "IsPlural":
 			continue
 		case "Extra", "extra", "Extras", "extras":
 			mergeContextExtra(extra, value)
@@ -69,7 +69,8 @@ func contextMapValuesString(values map[string]string) map[string]any {
 	extra := make(map[string]any, len(values))
 	for key, value := range values {
 		switch key {
-		case "Context", "Gender", "Location", "Formality", "Extra", "extra", "Extras", "extras":
+		case "Context", "Gender", "Location", "Formality", "Count", "IsPlural",
+			"Extra", "extra", "Extras", "extras":
 			continue
 		default:
 			extra[key] = value

context_test.go

@@ -15,6 +15,9 @@ func TestC_Good(t *testing.T) {
 	assert.Equal(t, "navigation", ctx.Context)
 	assert.Equal(t, "navigation", ctx.ContextString())
 	assert.Equal(t, "navigation", ctx.String())
+	assert.Equal(t, 1, ctx.CountInt())
+	assert.Equal(t, "1", ctx.CountString())
+	assert.False(t, ctx.IsPlural())
 }
 
 func TestC_Good_EmptyContext(t *testing.T) {
@@ -28,6 +31,7 @@ func TestC_Good_EmptyContext(t *testing.T) {
 func TestTranslationContext_NilReceiver_Good(t *testing.T) {
 	var ctx *TranslationContext
 
+	assert.Nil(t, ctx.Count(2))
 	assert.Nil(t, ctx.WithGender("masculine"))
 	assert.Nil(t, ctx.In("workspace"))
 	assert.Nil(t, ctx.Formal())
@@ -39,6 +43,9 @@ func TestTranslationContext_NilReceiver_Good(t *testing.T) {
 	assert.Equal(t, "", ctx.GenderString())
 	assert.Equal(t, "", ctx.LocationString())
 	assert.Equal(t, FormalityNeutral, ctx.FormalityValue())
+	assert.Equal(t, 1, ctx.CountInt())
+	assert.Equal(t, "1", ctx.CountString())
+	assert.False(t, ctx.IsPlural())
 }
 
 // --- WithGender ---
@@ -119,12 +126,16 @@ func TestTranslationContext_Get_Bad_NilExtra(t *testing.T) {
 
 func TestTranslationContext_FullChain_Good(t *testing.T) {
 	ctx := C("medical").
+		Count(3).
 		WithGender("feminine").
 		In("clinic").
 		Formal().
 		Set("speciality", "cardiology")
 
 	assert.Equal(t, "medical", ctx.ContextString())
+	assert.Equal(t, 3, ctx.CountInt())
+	assert.Equal(t, "3", ctx.CountString())
+	assert.True(t, ctx.IsPlural())
 	assert.Equal(t, "feminine", ctx.GenderString())
 	assert.Equal(t, "clinic", ctx.LocationString())
 	assert.Equal(t, FormalityFormal, ctx.FormalityValue())

i18n.go

@@ -252,11 +252,21 @@ func templateDataForRendering(data any) any {
 		if v == nil {
 			return nil
 		}
+		count, explicit := v.countValue()
+		if !explicit && v.Extra != nil {
+			if c, ok := v.Extra["Count"]; ok {
+				count = toInt(c)
+			} else if c, ok := v.Extra["count"]; ok {
+				count = toInt(c)
+			}
+		}
 		rendered := map[string]any{
 			"Context":   v.Context,
 			"Gender":    v.Gender,
 			"Location":  v.Location,
 			"Formality": v.Formality,
+			"Count":     count,
+			"IsPlural":  count != 1,
 			"Extra":     v.Extra,
 		}
 		for key, value := range v.Extra {

transform.go

@@ -11,14 +11,19 @@ func getCount(data any) int {
 		}
 		return d.CountInt()
 	case *TranslationContext:
-		if d == nil || d.Extra == nil {
+		if d == nil {
 			return 0
 		}
-		if c, ok := d.Extra["Count"]; ok {
-			return toInt(c)
+		if count, ok := d.countValue(); ok {
+			return count
 		}
-		if c, ok := d.Extra["count"]; ok {
-			return toInt(c)
+		if d.Extra != nil {
+			if c, ok := d.Extra["Count"]; ok {
+				return toInt(c)
+			}
+			if c, ok := d.Extra["count"]; ok {
+				return toInt(c)
+			}
 		}
 		return 0
 	case map[string]any: