Added help generator

src/main/java/me/vaperion/blade/Blade.java

@@ -7,6 +7,7 @@
 import me.vaperion.blade.command.argument.ProviderAnnotation;
 import me.vaperion.blade.command.bindings.Binding;
 import me.vaperion.blade.command.container.ContainerCreator;
+import me.vaperion.blade.command.help.HelpGenerator;
 import me.vaperion.blade.command.service.BladeCommandService;
 import me.vaperion.blade.completer.TabCompleter;
 import org.jetbrains.annotations.NotNull;
@@ -25,6 +26,7 @@ public class Blade {
     private final String fallbackPrefix;
     private final ContainerCreator<?> containerCreator;
     private final TabCompleter tabCompleter;
+    private final HelpGenerator helpGenerator;
 
     @Singular("bind0") private final Map<Map.Entry<Class<?>, Class<? extends ProviderAnnotation>>, BladeProvider<?>> customProviderMap;
     @Singular private final List<Binding> bindings;
@@ -64,6 +66,9 @@ public Blade build() {
                 if (blade.tabCompleter != null)
                     blade.commandService.setTabCompleter(blade.tabCompleter);
 
+                if (blade.helpGenerator != null)
+                    blade.commandService.setHelpGenerator(blade.helpGenerator);
+
                 for (Binding binding : blade.bindings) {
                     binding.bind(blade.commandService);
                 }

src/main/java/me/vaperion/blade/command/container/impl/BukkitCommandContainer.java

@@ -26,6 +26,7 @@
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Modifier;
 import java.util.*;
+import java.util.stream.Collectors;
 
 @Getter
 public class BukkitCommandContainer extends Command implements ICommandContainer {
@@ -195,9 +196,24 @@ public boolean execute(@NotNull CommandSender sender, @NotNull String alias, @No
         String resolvedAlias = alias;
 
         try {
+            String[] joined = joinAliasToArgs(alias, args);
+            String joinedStr = String.join(" ", joined);
 
-            Tuple<BladeCommand, String> resolved = resolveCommand(joinAliasToArgs(alias, args));
-            if (resolved == null) throw new BladeExitMessage("This command failed to execute as we couldn't find it's registration.");
+            BladeContext context = new BladeContext(new BukkitSender(sender), alias, args);
+
+            Tuple<BladeCommand, String> resolved = resolveCommand(joined);
+            if (resolved == null) {
+                List<BladeCommand> availableCommands = commandService.getAllBladeCommands()
+                        .stream().filter(c -> Arrays.stream(c.getAliases()).anyMatch(a -> a.toLowerCase().startsWith(joinedStr)))
+                        .filter(c -> this.checkPermission(sender, c).getLeft())
+                        .collect(Collectors.toList());
+
+                for (String line : commandService.getHelpGenerator().generate(context, availableCommands)) {
+                    sender.sendMessage(line);
+                }
+
+                return true;
+            }
 
             Tuple<Boolean, String> permissionResult = checkPermission(sender, resolved.getLeft());
             if (!permissionResult.getLeft()) throw new BladeExitMessage(permissionResult.getRight());
@@ -206,8 +222,6 @@ public boolean execute(@NotNull CommandSender sender, @NotNull String alias, @No
             resolvedAlias = resolved.getRight();
             int offset = Math.min(args.length, resolvedAlias.split(" ").length - 1);
 
-            BladeContext context = new BladeContext(new BukkitSender(sender), alias, args);
-
             if (command.isSenderParameter() && !command.getSenderType().isInstance(sender))
                 throw new BladeExitMessage("This command can only be executed by " + getSenderType(command.getSenderType()) + ".");
 

src/main/java/me/vaperion/blade/command/help/HelpGenerator.java

@@ -0,0 +1,13 @@
+package me.vaperion.blade.command.help;
+
+import me.vaperion.blade.command.container.BladeCommand;
+import me.vaperion.blade.command.context.BladeContext;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+@FunctionalInterface
+public interface HelpGenerator {
+    @NotNull
+    List<String> generate(@NotNull BladeContext context, @NotNull List<BladeCommand> commands);
+}

src/main/java/me/vaperion/blade/command/help/impl/DefaultHelpGenerator.java

@@ -0,0 +1,18 @@
+package me.vaperion.blade.command.help.impl;
+
+import me.vaperion.blade.command.container.BladeCommand;
+import me.vaperion.blade.command.context.BladeContext;
+import me.vaperion.blade.command.exception.BladeExitMessage;
+import me.vaperion.blade.command.help.HelpGenerator;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class DefaultHelpGenerator implements HelpGenerator {
+
+    @NotNull
+    @Override
+    public List<String> generate(@NotNull BladeContext context, @NotNull List<BladeCommand> commands) {
+        throw new BladeExitMessage("This command failed to execute as we couldn't find it's registration.");
+    }
+}

src/main/java/me/vaperion/blade/command/service/BladeCommandService.java

@@ -9,12 +9,15 @@
 import me.vaperion.blade.command.container.BladeProviderContainer;
 import me.vaperion.blade.command.container.ContainerCreator;
 import me.vaperion.blade.command.container.ICommandContainer;
+import me.vaperion.blade.command.help.HelpGenerator;
+import me.vaperion.blade.command.help.impl.DefaultHelpGenerator;
 import me.vaperion.blade.completer.TabCompleter;
 import me.vaperion.blade.completer.impl.DefaultTabCompleter;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class BladeCommandService {
 
@@ -27,6 +30,7 @@ public class BladeCommandService {
     @Setter @Getter private String fallbackPrefix = "blade";
     @Setter @Getter private ContainerCreator<?> containerCreator = ContainerCreator.NONE;
     @Setter @Getter private TabCompleter tabCompleter = new DefaultTabCompleter();
+    @Setter @Getter private HelpGenerator helpGenerator = new DefaultHelpGenerator();
 
     @Getter private final BladeCommandRegistrar commandRegistrar = new BladeCommandRegistrar(this);
     @Getter private final BladeCommandResolver commandResolver = new BladeCommandResolver(this);
@@ -37,6 +41,11 @@ public BladeCommandService() {
         new DefaultBindings().bind(this);
     }
 
+    @NotNull
+    public List<BladeCommand> getAllBladeCommands() {
+        return Collections.unmodifiableList(this.aliasCommands.values().stream().flatMap(List::stream).collect(Collectors.toList()));
+    }
+
     @NotNull
     public Map<String, ICommandContainer> getRegisteredCommands() {
         return Collections.unmodifiableMap(this.containerMap);