feat(scum-companion): validate typed adapters

plugins/examples/scum-server-plugin/companion/dispatcher.go

@@ -20,6 +20,7 @@ type SafeAdapter interface {
 }
 
 type HandlerAvailability struct {
+	BoundServerID string
 	ServerVersion string
 	Capabilities  map[string]bool
 	Approved      bool
@@ -66,7 +67,7 @@ func (registry *HandlerRegistry) Execute(ctx context.Context, command ClaimedCom
 	if err := validateDeclaredCommandAt(command, time.Now); err != nil {
 		return unsupportedResult("validation-failed"), nil
 	}
-	if !registry.availability.Approved || !registry.availability.Capabilities[command.CommandType] {
+	if strings.TrimSpace(registry.availability.BoundServerID) == "" || !registry.availability.Approved || !registry.availability.Capabilities[command.CommandType] {
 		return unsupportedResult("unsupported"), nil
 	}
 	handler, exists := registry.handlers[command.CommandType]
@@ -93,7 +94,104 @@ func validateDeclaredCommandAt(command ClaimedCommand, now func() time.Time) err
 			return fmt.Errorf("unsafe payload")
 		}
 	}
-	return nil
+	return validateCommandPayload(command.CommandType, command.Payload)
+}
+
+func validateCommandPayload(commandType string, payload map[string]any) error {
+	require := func(keys ...string) error {
+		for _, key := range keys {
+			if _, ok := payload[key]; !ok {
+				return fmt.Errorf("payload is incomplete")
+			}
+		}
+		return nil
+	}
+	noUnknown := func(keys ...string) error {
+		allowed := map[string]bool{}
+		for _, key := range keys {
+			allowed[key] = true
+		}
+		for key := range payload {
+			if !allowed[key] {
+				return fmt.Errorf("payload has unsupported field")
+			}
+		}
+		return nil
+	}
+	switch commandType {
+	case "config.read":
+		return noUnknown()
+	case "config.patch":
+		if err := require("revision", "fields"); err != nil {
+			return err
+		}
+		if err := noUnknown("revision", "fields"); err != nil {
+			return err
+		}
+		_, revisionOK := payload["revision"].(string)
+		fields, fieldsOK := payload["fields"].([]any)
+		if !revisionOK || !fieldsOK || len(fields) == 0 || len(fields) > 32 {
+			return fmt.Errorf("config patch payload is invalid")
+		}
+		return nil
+	case "companion.diagnostics":
+		if err := noUnknown("includeWindowState", "maxEntries"); err != nil {
+			return err
+		}
+		if value, ok := payload["includeWindowState"]; ok {
+			if _, valid := value.(bool); !valid {
+				return fmt.Errorf("diagnostics payload is invalid")
+			}
+		}
+		if value, ok := payload["maxEntries"]; ok {
+			if !boundedDiagnosticsEntries(value) {
+				return fmt.Errorf("diagnostics payload is invalid")
+			}
+		}
+		return nil
+	case "game-state.patch":
+		if err := require("playerId", "gameVersion", "expectedStateVersion", "safetyWindow", "reason", "changes"); err != nil {
+			return err
+		}
+		if err := noUnknown("playerId", "gameVersion", "expectedStateVersion", "safetyWindow", "reason", "changes"); err != nil {
+			return err
+		}
+		version, ok := payload["gameVersion"].(string)
+		changes, changesOK := payload["changes"].([]any)
+		if !ok || version == "" || !changesOK || len(changes) == 0 || len(changes) > 8 {
+			return fmt.Errorf("state patch payload is invalid")
+		}
+		return nil
+	case "reward.deliver":
+		if err := require("grantId", "playerId", "items"); err != nil {
+			return err
+		}
+		if err := noUnknown("grantId", "playerId", "items"); err != nil {
+			return err
+		}
+		_, grantOK := payload["grantId"].(string)
+		_, playerOK := payload["playerId"].(string)
+		items, itemsOK := payload["items"].([]any)
+		if !grantOK || !playerOK || !itemsOK || len(items) == 0 || len(items) > 8 {
+			return fmt.Errorf("reward payload is invalid")
+		}
+		return nil
+	case "player.notify":
+		if err := require("playerId", "message"); err != nil {
+			return err
+		}
+		if err := noUnknown("playerId", "message"); err != nil {
+			return err
+		}
+		_, playerOK := payload["playerId"].(string)
+		message, messageOK := payload["message"].(string)
+		if !playerOK || !messageOK || strings.TrimSpace(message) == "" || len(message) > 200 {
+			return fmt.Errorf("notification payload is invalid")
+		}
+		return nil
+	default:
+		return fmt.Errorf("command type is not declared")
+	}
 }
 
 func safeCommandField(key string, value any) bool {