Commands, step 1: parsing and handling.

dcf.properties.example

@@ -14,3 +14,6 @@ discord.token = tokenGoesHere
 # comment out discord.token if using us/pw tuple
 #discord.username = email
 #discord.password = superSecretPassword
+
+# Command prefix
+commands.prefix = !

src/main/java/net/pingex/dcf/commands/BasicParser.java

@@ -0,0 +1,48 @@
+package net.pingex.dcf.commands;
+
+import net.pingex.dcf.core.Configuration;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Basic command parser.
+ */
+public class BasicParser implements ICommandParser
+{
+	private Pattern commandPattern = Pattern.compile("^" + Configuration.COMMAND_PREFIX + "([:\\w]+)(?: (.*))?$");
+	private Pattern argsPattern = Pattern.compile("([^\"]\\S*|\".+?\")\\s*");
+
+	@Override
+	public boolean checkSyntax(String input)
+	{
+		return commandPattern.matcher(input).matches();
+	}
+
+	@Override
+	public String parseCommand(String input) throws ParserException
+	{
+		Matcher m = commandPattern.matcher(input);
+		if(!m.matches()) throw new ParserException("String cannot be parsed for a command.");
+		return m.group(1);
+	}
+
+	@Override
+	public List<String> parseArguments(String input) throws ParserException
+	{
+		Matcher mc = commandPattern.matcher(input);
+		if(!mc.matches()) throw new ParserException("String cannot be parsed for a command.");
+
+		// CASE: Command has no arg
+		if(mc.group(2) == null) return Collections.emptyList();
+
+		// CASE: Command has args
+		Matcher ma = argsPattern.matcher(mc.group(2));
+		List<String> argsOut = new ArrayList<>();
+		while(ma.find()) argsOut.add(ma.group(1).replace("\"", ""));
+		return argsOut;
+	}
+}

src/main/java/net/pingex/dcf/commands/CommandHandler.java

@@ -0,0 +1,45 @@
+package net.pingex.dcf.commands;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import sx.blah.discord.handle.impl.events.MessageReceivedEvent;
+
+import java.util.List;
+
+/**
+ * Landing class for a MRE
+ */
+public class CommandHandler
+{
+	/**
+	 * The one and only valid parser for now.
+	 */
+	public static final ICommandParser PARSER = new BasicParser();
+
+	/**
+	 * Logger
+	 */
+	private static final Logger LOGGER = LogManager.getLogger(CommandHandler.class);
+
+	/**
+	 * Landing method for a MRE
+	 */
+	public static void handle(MessageReceivedEvent event)
+	{
+		String command;
+		List<String> arguments;
+
+		try
+		{
+			command = PARSER.parseCommand(event.getMessage().getContent());
+			arguments = PARSER.parseArguments(event.getMessage().getContent());
+		}
+		catch(ParserException e)
+		{
+			return; // Not a command
+		}
+		LOGGER.debug("Attempting to run command {} by user #{}.", command, event.getMessage().getAuthor().getID());
+
+
+	}
+}

src/main/java/net/pingex/dcf/commands/ICommandParser.java

@@ -0,0 +1,32 @@
+package net.pingex.dcf.commands;
+
+import java.util.List;
+
+/**
+ * General interface for a command parser.
+ */
+public interface ICommandParser
+{
+	/**
+	 * Checks the syntax of a command.
+	 * @param input Input String, ie. the message content.
+	 * @return `true` if the string is a command, `false` otherwise.
+	 */
+	boolean checkSyntax(String input);
+
+	/**
+	 * Gives the command part of a command string.
+	 * @param input Input String, ie. the message content.
+	 * @return The command part of the inputted string.
+	 * @throws ParserException whether the inputted string cannot be parsed for a command.
+	 */
+	String parseCommand(String input) throws ParserException;
+
+	/**
+	 * Gives the arguments list of a command string.
+	 * @param input Input String, ie. the message content.
+	 * @return The arguments list of the inputted string.
+	 * @throws ParserException whether the inputted string cannot be parsed for a command.
+	 */
+	List<String> parseArguments(String input) throws ParserException;
+}

src/main/java/net/pingex/dcf/commands/ParserException.java

@@ -0,0 +1,17 @@
+package net.pingex.dcf.commands;
+
+/**
+ * Thrown when the parser cannot parse.
+ */
+public class ParserException extends Exception
+{
+	public ParserException()
+	{
+		super();
+	}
+
+	public ParserException(String message)
+	{
+		super(message);
+	}
+}

src/main/java/net/pingex/dcf/commands/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Contains everything related to commands parsing and executing.
+ */
+package net.pingex.dcf.commands;

src/main/java/net/pingex/dcf/core/Configuration.java

@@ -89,6 +89,11 @@ public class Configuration
 	 */
 	public static String DATA_DIR = "data";
 
+	/**
+	 * Command prefix string
+	 */
+	public static String COMMAND_PREFIX = "!";
+
 	/**
 	 * Tells if the bot is configured to connect using a token or an username/password tuple.
 	 * @return Whether the main connection is a bot, or not
@@ -106,6 +111,7 @@ public class Configuration
 		BOT_NAME = store.getString("general.bot_name", BOT_NAME);
 		PLUGINS_DIR = store.getString("general.plugins_dir", PLUGINS_DIR);
 		DATA_DIR = store.getString("general.storage_dir", DATA_DIR);
+		COMMAND_PREFIX = store.getString("commands.prefix", COMMAND_PREFIX);
 
 		// Validate main connection username/password or token
 		if(isConnectionToken())

src/main/java/net/pingex/dcf/core/CoreEventsHandler.java

@@ -1,5 +1,6 @@
 package net.pingex.dcf.core;
 
+import net.pingex.dcf.commands.CommandHandler;
 import net.pingex.dcf.modularity.PluginWrapper;
 import net.pingex.dcf.modularity.events.EventManager;
 import org.apache.logging.log4j.LogManager;
@@ -53,6 +54,7 @@ public class CoreEventsHandler
 	public static void onMessageReceived(MessageReceivedEvent event)
 	{
 		LOGGER.trace("Received message from channel #{}.", event.getMessage().getChannel().getID());
+		CommandHandler.handle(event);
 	}
 
 	@EventSubscriber
@@ -92,7 +94,7 @@ public class CoreEventsHandler
 	public static void pluginRunning(PluginWrapper plugin)
 	{
 		EventManager.getInstance().checkAndRegister(plugin); // Hook: event handlers
-		// TODO: Hook: commands
+		// TODO: Hook: register commands (if implements appropriate interface)
 	}
 
 	/**
@@ -102,6 +104,7 @@ public class CoreEventsHandler
 	public static void pluginStopped(PluginWrapper plugin)
 	{
 		EventManager.getInstance().unregister(plugin); // Hook: event handlers
+		// TODO: Hook: unregister commands
 	}
 
 	/**