1 files changed, 140 insertions, 0 deletions
diff --git a/id/server/idserverlib/src/main/java/at/gv/egovernment/moa/id/moduls/moduleregistration/ModuleRegistration.java b/id/server/idserverlib/src/main/java/at/gv/egovernment/moa/id/moduls/moduleregistration/ModuleRegistration.java
new file mode 100644
index 000000000..522e5c7eb
--- /dev/null
+++ b/id/server/idserverlib/src/main/java/at/gv/egovernment/moa/id/moduls/moduleregistration/ModuleRegistration.java
@@ -0,0 +1,140 @@
+package at.gv.egovernment.moa.id.moduls.moduleregistration;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.ServiceLoader;
+
+import javax.annotation.PostConstruct;
+
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.io.Resource;
+
+import com.datentechnik.process_engine.ProcessEngine;
+import com.datentechnik.process_engine.api.ExecutionContext;
+
+/**
+ * This class handles registering modules. The modules are detected either with
+ * the ServiceLoader mechanism or via Spring. All detected modules are ranked
+ * according to their priority.
+ */
+public class ModuleRegistration {
+
+	private static ModuleRegistration instance = new ModuleRegistration();
+
+	private List<AuthModule> orderedModules = new ArrayList<>();
+
+	@Autowired
+	private ApplicationContext ctx;
+
+	@Autowired
+	ProcessEngine processEngine;
+
+	private Logger log = LoggerFactory.getLogger(getClass());
+
+	public static ModuleRegistration getInstance() {
+		return instance;
+	}
+
+	private ModuleRegistration() {
+	}
+
+	@PostConstruct
+	private void init() {
+		// load modules via the ServiceLoader
+		initServiceLoaderModules();
+
+		// load modules via Spring
+		initSpringModules();
+
+		// order modules according to their priority
+		orderModules();
+	}
+
+	/**
+	 * Discovers modules which use the ServiceLoader mechanism.
+	 */
+	private void initServiceLoaderModules() {
+		log.debug("Discovering modules which use the ServiceLoader mechanism.");
+		ServiceLoader<AuthModule> loader = ServiceLoader.load(AuthModule.class);
+		Iterator<AuthModule> modules = loader.iterator();
+		while (modules.hasNext()) {
+			AuthModule module = modules.next();
+			registerResourceUris(module);
+			orderedModules.add(module);
+		}
+	}
+
+	/**
+	 * Discovers modules which use Spring.
+	 */
+	private void initSpringModules() {
+		log.debug("Discovering Spring modules.");
+		Map<String, AuthModule> modules = ctx.getBeansOfType(AuthModule.class);
+		for (AuthModule module : modules.values()) {
+			registerResourceUris(module);
+			orderedModules.add(module);
+		}
+	}
+
+	/**
+	 * Registers the resource uris for the module.
+	 * 
+	 * @param module
+	 *            the module.
+	 */
+	private void registerResourceUris(AuthModule module) {
+		for (String uri : module.getProcessDefinitions()) {
+			Resource resource = ctx.getResource(uri);
+			if (resource.exists()) {
+				log.debug("Registering process definition resource url: '{}'.", resource);
+				// TODO: register resource with the process engine
+				// processEngine.registerResourceUri(resource);
+			} else {
+				log.info("Resource url: '{}' does NOT exist.", resource);
+			}
+		}
+	}
+
+	/**
+	 * Order the modules in descending order according to their priority.
+	 */
+	private void orderModules() {
+		Collections.sort(orderedModules, new Comparator<AuthModule>() {
+			@Override
+			public int compare(AuthModule thisAuthModule, AuthModule otherAuthModule) {
+				int thisOrder = thisAuthModule.getPriority();
+				int otherOrder = otherAuthModule.getPriority();
+				return (thisOrder < otherOrder ? -1 : (thisOrder == otherOrder ? 0 : 1));
+			}
+		});
+		log.debug("Modules are ordered in descending order, according to their priority.");
+	}
+
+	/**
+	 * Returns the process id of the first process, in the highest ranked
+	 * module, which is able to work with the given execution context.
+	 * 
+	 * @param context
+	 *            the {@link ExecutionContext}.
+	 * @return the process id or {@code null}
+	 */
+	public String selectProcess(ExecutionContext context) {
+		for (AuthModule module : orderedModules) {
+			String id = module.selectProcess(context);
+			if (StringUtils.isNotEmpty(id)) {
+				log.debug("Process with id '{}' selected, for context '{}'.", id, context);
+				return id;
+			}
+		}
+		log.info("No process is able to handle context '{}'.", context);
+		return null;
+	}
+}