Added list command to CLI.

src/cli/client/handlers/TaskActionHandler.java

@@ -11,12 +11,14 @@
 import cli.messages.TaskExecuteMessage;
 import cli.messages.TaskGroupMessage;
 import cli.messages.TaskIdentifier;
+import cli.messages.TaskListMessage;
 import cli.messages.TaskMessage;
 import cli.messages.TaskRemoveMessage;
 import cli.server.CliRpcCodec;
 import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 import net.sourceforge.argparse4j.inf.Subparsers;
+import utilities.IJsonable;
 import utilities.JSONUtility;
 import utilities.NumberUtility;
 
@@ -29,9 +31,9 @@ public void addArguments(Subparsers subparsers) {
 		Subparser parser = subparsers.addParser("task").setDefault("module", "task").help("Task management.");
 
 		parser.addArgument("-a", "--action").required(true)
-        		.choices("add", "remove", "execute")
+        		.choices("add", "remove", "execute", "ls", "list")
         		.help("Specify action on task.");
-		parser.addArgument("-n", "--name").required(true)
+		parser.addArgument("-n", "--name").setDefault("")
 				.help("Name of the task, or its index (zero based) in the group if the task exists. "
 						+ "This tries to interpret this as an integer index first, then as a task name. "
 						+ "For remove action, if multiple tasks share the same name, "
@@ -53,6 +55,8 @@ public void handle(Namespace namespace) {
 			handleRemove(namespace);
 		} else if (action.equals("execute")) {
 			handleExecute(namespace);
+		} else if (action.equals("ls") || action.equals("list")) {
+			handleList(namespace);
 		} else {
 			LOGGER.log(Level.SEVERE, "Unknown task action " + action);
 			CliExitCodes.UNKNOWN_ACTION.exit();
@@ -71,8 +75,7 @@ private void handleAdd(Namespace namespace) {
 
 		TaskAddMessage message = TaskAddMessage.of().setFilePath(filePath)
 				.setTaskIdentifier(TaskIdentifier.of().setGroup(taskGroupMessage).setTask(taskMessage));
-		byte[] data = CliRpcCodec.encode(JSONUtility.jsonToString(message.jsonize()).getBytes(CliRpcCodec.ENCODING));
-		sendRequest("/task/add", data);
+		sendRequest("/task/add", message);
 	}
 
 	private void handleRemove(Namespace namespace) {
@@ -81,8 +84,7 @@ private void handleRemove(Namespace namespace) {
 
 		TaskRemoveMessage message = TaskRemoveMessage.of()
 				.setTaskIdentifier(TaskIdentifier.of().setGroup(taskGroupMessage).setTask(taskMessage));
-		byte[] data = CliRpcCodec.encode(JSONUtility.jsonToString(message.jsonize()).getBytes(CliRpcCodec.ENCODING));
-		sendRequest("/task/remove", data);
+		sendRequest("/task/remove", message);
 	}
 
 	private void handleExecute(Namespace namespace) {
@@ -91,8 +93,13 @@ private void handleExecute(Namespace namespace) {
 
 		TaskExecuteMessage message = TaskExecuteMessage.of()
 				.setTaskIdentifier(TaskIdentifier.of().setGroup(taskGroupMessage).setTask(taskMessage));
-		byte[] data = CliRpcCodec.encode(JSONUtility.jsonToString(message.jsonize()).getBytes(CliRpcCodec.ENCODING));
-		sendRequest("/task/execute", data);
+		sendRequest("/task/execute", message);
+	}
+
+	private void handleList(Namespace namespace) {
+		TaskGroupMessage taskGroupMessage = getGroup(namespace);
+		TaskListMessage message = TaskListMessage.of().setGroup(taskGroupMessage);
+		sendRequest("/task/list", message);
 	}
 
 	private TaskGroupMessage getGroup(Namespace namespace) {
@@ -108,6 +115,11 @@ private TaskGroupMessage getGroup(Namespace namespace) {
 
 	private TaskMessage getTask(Namespace namespace) {
 		String taskName = namespace.getString("name");
+		if (taskName.isEmpty()) {
+			LOGGER.warning("Task must be specified.");
+			CliExitCodes.INVALID_ARGUMENTS.exit();
+		}
+
 		TaskMessage taskMessage = TaskMessage.of();
 		if (NumberUtility.isNonNegativeInteger(taskName)) {
 			taskMessage.setIndex(Integer.parseInt(taskName));
@@ -117,6 +129,11 @@ private TaskMessage getTask(Namespace namespace) {
 		return taskMessage;
 	}
 
+	private void sendRequest(String path, IJsonable message) {
+		byte[] data = CliRpcCodec.encode(JSONUtility.jsonToString(message.jsonize()).getBytes(CliRpcCodec.ENCODING));
+		sendRequest(path, data);
+	}
+
 	private void sendRequest(String path, byte[] data) {
 		try {
 			byte[] responseData = httpClient.sendPost(path, data);

src/cli/messages/TaskListMessage.java

@@ -0,0 +1,49 @@
+package cli.messages;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import argo.jdom.JsonNode;
+import argo.jdom.JsonNodeFactories;
+import argo.jdom.JsonRootNode;
+import argo.jdom.JsonStringNode;
+import utilities.IJsonable;
+
+public class TaskListMessage implements IJsonable {
+	private TaskGroupMessage group;
+
+	private TaskListMessage() {}
+	public static TaskListMessage of() {
+		return new TaskListMessage();
+	}
+
+	private TaskListMessage(TaskGroupMessage group) {
+		this.group = group;
+	}
+
+	public static TaskListMessage parseJSON(JsonNode node) {
+		TaskGroupMessage group = null;
+		if (node.isObjectNode("group")) {
+			group = TaskGroupMessage.parseJSON(node.getNode("group"));
+		}
+
+		return new TaskListMessage(group);
+	}
+
+	@Override
+	public JsonRootNode jsonize() {
+		Map<JsonStringNode, JsonNode> data = new HashMap<>();
+		if (group != null) {
+			data.put(JsonNodeFactories.string("group"), group.jsonize());
+		}
+		return JsonNodeFactories.object(data);
+	}
+
+	public TaskGroupMessage getGroup() {
+		return group;
+	}
+	public TaskListMessage setGroup(TaskGroupMessage group) {
+		this.group = group;
+		return this;
+	}
+}

src/cli/server/CliServer.java

@@ -15,6 +15,7 @@
 import cli.server.handlers.HttpHandlerWithBackend;
 import cli.server.handlers.TaskAddActionHandler;
 import cli.server.handlers.TaskExecuteActionHandler;
+import cli.server.handlers.TaskListActionHandler;
 import cli.server.handlers.TaskRemoveActionHandler;
 import cli.server.handlers.UpAndRunningHandler;
 import core.config.CliConfig;
@@ -52,6 +53,7 @@ private Map<String, HttpHandlerWithBackend> createHandlers() {
 		output.put("/task/add", new TaskAddActionHandler());
 		output.put("/task/remove", new TaskRemoveActionHandler());
 		output.put("/task/execute", new TaskExecuteActionHandler());
+		output.put("/task/list", new TaskListActionHandler());
 		return output;
 	}
 

src/cli/server/handlers/TaskActionHandler.java

@@ -57,17 +57,21 @@ protected UserDefinedAction getTask(TaskGroup group, TaskIdentifier taskIdentifi
 	}
 
 	protected TaskGroup getGroup(TaskIdentifier taskIdentifier) {
-		int index = taskIdentifier.getGroup().getIndex();
-		String name = taskIdentifier.getGroup().getName();
+		return getGroup(taskIdentifier.getGroup());
+	}
+
+	protected TaskGroup getGroup(TaskGroupMessage taskGroup) {
+		int index = taskGroup.getIndex();
+		String name = taskGroup.getName();
 		if (index == TaskGroupMessage.UNKNOWN_INDEX && name.isEmpty()) {
 			index = 0;
 		}
 
 		TaskGroup group = null;
-		if (taskIdentifier.getGroup() != null) {
-			group = backEndHolder.getTaskGroup(taskIdentifier.getGroup().getIndex());
+		if (taskGroup != null) {
+			group = backEndHolder.getTaskGroup(index);
 			if (group == null) {
-				group = backEndHolder.getTaskGroup(taskIdentifier.getGroup().getName());
+				group = backEndHolder.getTaskGroup(name);
 			}
 		}
 		return group;

src/cli/server/handlers/TaskListActionHandler.java

@@ -0,0 +1,37 @@
+package cli.server.handlers;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.apache.http.nio.protocol.HttpAsyncExchange;
+
+import argo.jdom.JsonNode;
+import cli.messages.TaskGroupMessage;
+import cli.messages.TaskListMessage;
+import cli.server.CliRpcCodec;
+import cli.server.utils.EnumerationUtils;
+import core.userDefinedTask.TaskGroup;
+import core.userDefinedTask.UserDefinedAction;
+
+public class TaskListActionHandler extends TaskActionHandler {
+
+	@Override
+	protected Void handleTaskActionWithBackend(HttpAsyncExchange exchange, JsonNode request) throws IOException {
+		TaskListMessage message = TaskListMessage.parseJSON(request);
+		boolean noGroup = message.getGroup() == null ||
+				(message.getGroup().getIndex() == TaskGroupMessage.UNKNOWN_INDEX &&
+				message.getGroup().getName().isEmpty());
+
+		if (noGroup) {
+			List<String> names = backEndHolder.getTaskGroups().stream().map(TaskGroup::getName).collect(Collectors.toList());
+			return CliRpcCodec.prepareResponse(exchange, 200, EnumerationUtils.enumerate(names));
+		}
+		TaskGroup group = getGroup(message.getGroup());
+		if (group == null) {
+			return CliRpcCodec.prepareResponse(exchange, 400, "Cannot find group with given arguments.");
+		}
+		List<String> taskNames = group.getTasks().stream().map(UserDefinedAction::getName).collect(Collectors.toList());
+		return CliRpcCodec.prepareResponse(exchange, 200, EnumerationUtils.enumerate(taskNames));
+	}
+}

src/cli/server/utils/EnumerationUtils.java

@@ -0,0 +1,24 @@
+package cli.server.utils;
+
+public class EnumerationUtils {
+	private EnumerationUtils() {}
+
+	/**
+	 * Converts an iterable of Strings into a readable list.
+	 * Index starts from 0.
+	 *
+	 *  E.g. [aa,bb,cc,dd] will become
+	 *  0) aa
+	 *  1) bb
+	 *  2) cc
+	 *  3) dd
+	 */
+	public static String enumerate(Iterable<String> data) {
+		StringBuilder builder = new StringBuilder();
+		int i = 0;
+		for (String s : data) {
+			builder.append(String.format("%d) %s\n", i++, s));
+		}
+		return builder.toString();
+	}
+}