Hopefully finished help command

src/main/java/com/alttd/commandManager/CommandManager.java

@@ -27,4 +27,11 @@ public class CommandManager extends ListenerAdapter {
         String[] args = Arrays.copyOfRange(s, 1, s.length);
     }
 
+    public List<DiscordCommand> getCommands() {
+        return commands;
+    }
+
+    public String getPrefix(long guildId) {
+        return commandPrefixes.getOrDefault(guildId, "!");
+    }
 }

src/main/java/com/alttd/commandManager/DiscordCommand.java

@@ -1,6 +1,7 @@
 package com.alttd.commandManager;
 
 import net.dv8tion.jda.api.entities.Member;
+import net.dv8tion.jda.api.entities.TextChannel;
 import net.dv8tion.jda.api.entities.User;
 
 import java.util.List;
@@ -13,12 +14,16 @@ public abstract class DiscordCommand {
         return "command." + getName();
     }
 
-    public abstract String execute(String[] args, Member commandSource);
+    public abstract String execute(String[] args, Member commandSource, TextChannel textChannel);
 
-    public abstract String execute(String[] args, User commandSource);
+    public abstract String execute(String[] args, User commandSource, TextChannel textChannel);
 
     public abstract String getHelpMessage();
 
-    public abstract List<String> getAlias();
+    public String getExtendedHelpMessage() {
+        return getHelpMessage();
+    }
+
+    public abstract List<String> getAliases();
 
 }

src/main/java/com/alttd/commandManager/commands/CommandHelp.java

@@ -1,26 +1,72 @@
 package com.alttd.commandManager.commands;
 
+import com.alttd.AltitudeBot;
+import com.alttd.commandManager.CommandManager;
 import com.alttd.commandManager.DiscordCommand;
 import com.alttd.config.MessagesConfig;
+import com.alttd.permissions.PermissionManager;
+import com.alttd.templates.Parser;
+import com.alttd.templates.Template;
+import com.alttd.util.Logger;
+import com.alttd.util.Util;
 import net.dv8tion.jda.api.entities.Member;
+import net.dv8tion.jda.api.entities.PrivateChannel;
+import net.dv8tion.jda.api.entities.TextChannel;
 import net.dv8tion.jda.api.entities.User;
 
 import java.util.List;
+import java.util.Optional;
 
 public class CommandHelp extends DiscordCommand {
+
+    private final CommandManager commandManager;
+
+    public CommandHelp(CommandManager commandManager) {
+        this.commandManager = commandManager;
+    }
+
     @Override
     public String getName() {
         return "help";
     }
 
     @Override
-    public String execute(String[] args, Member commandSource) {
-        return null;
+    public String execute(String[] args, Member commandSource, TextChannel textChannel) {
+        return execute(args, textChannel, commandSource.getIdLong(), textChannel.getGuild().getIdLong(), Util.getGroupIds(commandSource));
     }
 
     @Override
-    public String execute(String[] args, User commandSource) {
-        return null;
+    public String execute(String[] args, User commandSource, TextChannel textChannel) {
+        if (!(textChannel instanceof PrivateChannel))
+            Logger.warning("Using User when executing command on Member: % Command: %", commandSource.getAsMention(), getName());
+        return execute(args, textChannel, commandSource.getIdLong(), 0, null);
+    }
+
+    public String execute(String[] args, TextChannel textChannel, long userId, long guildId, List<Long> groupIds) {
+        PermissionManager permissionManager = AltitudeBot.getInstance().getPermissionManager();
+        StringBuilder helpMessage = new StringBuilder();
+        if (args.length == 0) {
+            commandManager.getCommands().stream()
+                    .filter(command -> permissionManager.hasPermission(
+                            textChannel,
+                            userId,
+                            groupIds,
+                            command.getPermission()))
+                    .forEach(command -> helpMessage.append(command.getHelpMessage()));
+        } else {
+            String arg = args[0].toLowerCase();
+            Optional<DiscordCommand> first = commandManager.getCommands().stream()
+                    .filter(command -> command.getName().equals(arg)
+                            || command.getAliases().contains(arg)).findFirst();
+            if (first.isEmpty())
+                return Parser.parse(MessagesConfig.INVALID_COMMAND_ARGS,
+                        Template.of("args", arg),
+                        Template.of("command", getName()),
+                        Template.of("prefix", commandManager.getPrefix(guildId)));
+            DiscordCommand discordCommand = first.get();
+            helpMessage.append(discordCommand.getExtendedHelpMessage());
+        }
+        return Parser.parse(MessagesConfig.HELP_MESSAGE_TEMPLATE, Template.of("commands", helpMessage.toString()));
     }
 
     @Override
@@ -29,7 +75,7 @@ public class CommandHelp extends DiscordCommand {
     }
 
     @Override
-    public List<String> getAlias() {
+    public List<String> getAliases() {
         return null;
     }
 }