Adds OpenAPI oneOf for connector properties at runtime

server/src/com/mirth/connect/server/servlets/SwaggerServlet.java

@@ -10,16 +10,25 @@
 package com.mirth.connect.server.servlets;
 
 import com.mirth.connect.client.core.BrandingConstants;
+
+import io.swagger.v3.core.converter.ModelConverters;
 import io.swagger.v3.jaxrs2.integration.ServletOpenApiContextBuilder;
 import io.swagger.v3.oas.integration.OpenApiConfigurationException;
 import io.swagger.v3.oas.integration.SwaggerConfiguration;
+import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.info.Info;
+import io.swagger.v3.oas.models.media.ComposedSchema;
+import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.servers.Server;
 
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
 import java.util.stream.Collectors;
 
 import javax.servlet.ServletConfig;
@@ -28,8 +37,13 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.reflections.Reflections;
+import org.reflections.scanners.SubTypesScanner;
+import org.reflections.util.ClasspathHelper;
+import org.reflections.util.ConfigurationBuilder;
 
 import com.mirth.connect.client.core.Version;
+import com.mirth.connect.donkey.model.channel.ConnectorProperties;
 
 public class SwaggerServlet extends HttpServlet {
 
@@ -66,6 +80,7 @@ public void init(ServletConfig config) throws ServletException {
 				.version(apiVersion.toString());
 
 		oas.info(info);
+		addConnectorPropertiesSchemas(oas);
 		SwaggerConfiguration oasConfig = new SwaggerConfiguration()
 				.openAPI(oas)
 				.resourceClasses(resourceClasses.stream().map(Class::getName).collect(Collectors.toSet()));
@@ -81,4 +96,78 @@ public void init(ServletConfig config) throws ServletException {
 			throw new ServletException(e.getMessage(), e);
 		}
 	}
+
+	private void addConnectorPropertiesSchemas(OpenAPI openApi) {
+		Components components = openApi.getComponents();
+		if (components == null) {
+			components = new Components();
+			openApi.setComponents(components);
+		}
+
+		Map<String, Schema> schemas = components.getSchemas();
+		if (schemas == null) {
+			schemas = new java.util.LinkedHashMap<>();
+			components.setSchemas(schemas);
+		}
+
+		SortedSet<Class<? extends ConnectorProperties>> subtypes = findConnectorPropertiesSubtypes();
+		if (subtypes.isEmpty()) {
+			return;
+		}
+
+		ComposedSchema connectorPropertiesSchema = new ComposedSchema();
+		Schema<?> existingSchema = schemas.get("ConnectorProperties");
+		if (existingSchema instanceof ComposedSchema) {
+			connectorPropertiesSchema = (ComposedSchema) existingSchema;
+		}
+		connectorPropertiesSchema.setOneOf(new ArrayList<>());
+
+		for (Class<? extends ConnectorProperties> subtype : subtypes) {
+			addSubtypeSchema(schemas, connectorPropertiesSchema, subtype);
+		}
+
+		schemas.put("ConnectorProperties", connectorPropertiesSchema);
+	}
+
+	private SortedSet<Class<? extends ConnectorProperties>> findConnectorPropertiesSubtypes() {
+		Reflections reflections = new Reflections(new ConfigurationBuilder()
+				.addUrls(ClasspathHelper.forClassLoader())
+				.addScanners(new SubTypesScanner(false)));
+
+		SortedSet<Class<? extends ConnectorProperties>> subtypes = new TreeSet<>(
+				Comparator.comparing(Class::getName));
+		for (Class<? extends ConnectorProperties> subtype : reflections.getSubTypesOf(ConnectorProperties.class)) {
+			if (!subtype.isInterface() && !java.lang.reflect.Modifier.isAbstract(subtype.getModifiers())) {
+				subtypes.add(subtype);
+			}
+		}
+		return subtypes;
+	}
+
+	private void addSubtypeSchema(Map<String, Schema> schemas, ComposedSchema connectorPropertiesSchema, Class<? extends ConnectorProperties> subtype) {
+		Map<String, Schema> subtypeSchemas = ModelConverters.getInstance().readAll(subtype);
+		if (subtypeSchemas != null) {
+			subtypeSchemas.forEach(schemas::putIfAbsent);
+		}
+
+		String schemaName = resolveSchemaName(subtypeSchemas, subtype);
+		if (schemaName != null) {
+			Schema<?> refSchema = new Schema<>();
+			refSchema.set$ref("#/components/schemas/" + schemaName);
+			connectorPropertiesSchema.addOneOfItem(refSchema);
+		}
+	}
+
+	private String resolveSchemaName(Map<String, Schema> subtypeSchemas, Class<? extends ConnectorProperties> subtype) {
+		if (subtypeSchemas == null || subtypeSchemas.isEmpty()) {
+			return null;
+		}
+
+		String simpleName = subtype.getSimpleName();
+		if (subtypeSchemas.containsKey(simpleName)) {
+			return simpleName;
+		}
+
+		return subtypeSchemas.keySet().iterator().next();
+	}
 }