chat/translate.go: Concept implementation of client-side translations.

server/player/chat/chat.go

@@ -40,6 +40,18 @@ func (chat *Chat) WriteString(s string) (n int, err error) {
 	return len(s), nil
 }
 
+func (chat *Chat) Writet(t Translation) {
+	chat.m.Lock()
+	defer chat.m.Unlock()
+	for _, subscriber := range chat.subscribers {
+		if translator, ok := subscriber.(Translator); ok {
+			translator.Messaget(t)
+			continue
+		}
+		subscriber.Message(t.String())
+	}
+}
+
 // Subscribe adds a subscriber to the chat, sending it every message written to
 // the chat. In order to remove it again, use Chat.Unsubscribe().
 func (chat *Chat) Subscribe(s Subscriber) {

server/player/chat/subscriber.go

@@ -17,6 +17,10 @@ type Subscriber interface {
 	Message(a ...any)
 }
 
+type Translator interface {
+	Messaget(t Translation)
+}
+
 // StdoutSubscriber is an implementation of Subscriber that forwards messages
 // sent to the chat to the stdout.
 type StdoutSubscriber struct{}

server/player/chat/translate.go

@@ -0,0 +1,40 @@
+package chat
+
+import (
+	"fmt"
+	"github.com/df-mc/dragonfly/server/internal/sliceutil"
+)
+
+var JoinMessage = translate("%multiplayer.player.joined", 1, "%v joined the game")
+var QuitMessage = translate("%multiplayer.player.left", 1, "%v left the game")
+
+func translate(format string, params int, fallback string) Translatable {
+	return Translatable{format: format, params: params, fallback: fallback}
+}
+
+type Translatable struct {
+	format   string
+	params   int
+	fallback string
+}
+
+func (t Translatable) F(a ...any) Translation {
+	if len(a) != t.params {
+		panic(fmt.Sprintf("translation '%v' requires exactly %v parameters, got %v", t.format, t.params, len(a)))
+	}
+	params := make([]string, len(a))
+	for i, arg := range a {
+		params[i] = fmt.Sprint(arg)
+	}
+	return Translation{format: t.format, fallback: t.fallback, params: params}
+}
+
+type Translation struct {
+	format   string
+	fallback string
+	params   []string
+}
+
+func (t Translation) String() string {
+	return fmt.Sprintf(t.fallback, sliceutil.Convert[any](t.params)...)
+}

server/session/session.go

@@ -256,6 +256,7 @@ func (s *Session) close(tx *world.Tx, c Controllable) {
 	s.chunkLoader.Close(tx)
 
 	if s.quitMessage != "" {
+		chat.Global.Writet(chat.QuitMessage.F(s.conn.IdentityData().DisplayName))
 		_, _ = fmt.Fprintln(chat.Global, text.Colourf("<yellow>%v</yellow>", fmt.Sprintf(s.quitMessage, s.conn.IdentityData().DisplayName)))
 	}
 	chat.Global.Unsubscribe(c)