Adding client-side and server-side interactions. Also adds purpur/paper support

sdk/context.go

@@ -15,6 +15,7 @@ type Context struct {
 	snapshot    *SnapshotSubscription
 }
 
+// Broadcast queues a message to be sent to all players.
 func (context *Context) Broadcast(message string) {
 	context.actions = append(context.actions, ActionRequest{
 		Type: "minecraft:chat.broadcast",
@@ -24,6 +25,7 @@ func (context *Context) Broadcast(message string) {
 	})
 }
 
+// SendMessage queues a message to be sent to a player.
 func (context *Context) SendMessage(playerUUID, message string) {
 	context.actions = append(context.actions, ActionRequest{
 		Type: "minecraft:chat.player",
@@ -34,7 +36,29 @@ func (context *Context) SendMessage(playerUUID, message string) {
 	})
 }
 
-func (context *Context) SystemCall(name string, payload any) string {
+// DisplayClientMessage appends a local-only message to the Minecraft client
+// chat. Client runtimes reject server action types such as SendMessage.
+func (context *Context) DisplayClientMessage(message string) {
+	context.actions = append(context.actions, ActionRequest{
+		Type: "minecraft:client.chat.display",
+		Payload: map[string]any{
+			"message": message,
+		},
+	})
+}
+
+// SystemCall queues one of the system calls built into the bridge.
+func (context *Context) SystemCall(callType SystemCallType, payload any) string {
+	return context.queueSystemCall(string(callType), payload)
+}
+
+// CustomSystemCall queues a system call registered by another mod.
+func (context *Context) CustomSystemCall(name string, payload any) string {
+	return context.queueSystemCall(name, payload)
+}
+
+// queueSystemCall queues a system call to be executed by the bridge.
+func (context *Context) queueSystemCall(name string, payload any) string {
 	id := fmt.Sprintf("call-%d", callSequence.Add(1))
 	context.systemCalls = append(context.systemCalls, SystemCallRequest{
 		ID:      id,
@@ -44,6 +68,7 @@ func (context *Context) SystemCall(name string, payload any) string {
 	return id
 }
 
+// SubscribeSnapshot queues a snapshot subscription to be executed by the bridge.
 func (context *Context) SubscribeSnapshot(entities bool, blocks ...BlockReference) {
 	context.snapshot = &SnapshotSubscription{
 		Entities: entities,
@@ -51,6 +76,7 @@ func (context *Context) SubscribeSnapshot(entities bool, blocks ...BlockReferenc
 	}
 }
 
+// Log queues a log message to be sent to the server.
 func (context *Context) Log(level, message string) {
 	context.logs = append(context.logs, LogEntry{
 		Stream:             "sdk",