minecraft-kajetans-core-mod/src/main/java/me/kcm/command/ModServerCommandManager.java

package me.kcm.command;

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.stream.Collectors;
import javax.annotation.Nullable;
import net.minecraft.command.CommandBase;
import net.minecraft.command.ICommand;
import net.minecraft.command.ICommandSender;
import net.minecraft.command.ServerCommandManager;
import net.minecraft.server.MinecraftServer;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.text.ITextComponent;
import net.minecraft.util.text.TextComponentTranslation;
import net.minecraft.util.text.TextFormatting;
import net.minecraftforge.event.CommandEvent;

public class ModServerCommandManager extends ServerCommandManager
{
    private LinkedList<String> events = new LinkedList<>();
    private ICommandManager manager;
    
    public ModServerCommandManager(MinecraftServer serverIn) 
    {
        super(serverIn);
        // the manager must not be null
        this.manager = new ICommandManager() 
        {
            @Override
            public boolean hasPermission(ICommandSender cs, String perm) 
            {
                return true;
            }

            @Override
            public boolean executeCustomCommand(ICommandSender cs, String command, String[] args) 
            {
                return false;
            }

            @Override
            public void printMissingCommand(ICommandSender cs, String command) 
            {
            }

            @Override
            public void printMissingPermission(ICommandSender cs, ICommand command) 
            {
            }

            @Override
            public void onRegisterCommand(ICommand command, String domain)
            {
            }
        };
    }
    
    public void setPermissionManager(ICommandManager manager)
    {
        // the manager must not be null
        if(manager == null)
        {
            throw new NullPointerException();
        }
        this.manager = manager;
    }
    
    public void registerRegistryEvent(String s)
    {
        events.add(s);
    }
    
    @Override
    public void notifyListener(ICommandSender cs, ICommand command, int flags, String key, Object... args)
    {
        ITextComponent text = new TextComponentTranslation("chat.type.admin", new Object[] {cs.getName(), new TextComponentTranslation(key, args)});
        text.getStyle().setColor(TextFormatting.GRAY);
        text.getStyle().setItalic(true);
        cs.sendMessage(text);
    }
    
    private String[] dropFirstString(String[] input)
    {
        String[] astring = new String[input.length - 1];
        System.arraycopy(input, 1, astring, 0, input.length - 1);
        return astring;
    }
    
    @Override
    public int executeCommand(ICommandSender sender, String rawCommand)
    {
        rawCommand = rawCommand.trim();
        if(rawCommand.startsWith("/"))
        {
            rawCommand = rawCommand.substring(1);
        }

        String[] args = rawCommand.split(" ");
        String command = args[0].toLowerCase();
        args = dropFirstString(args);
        
        ICommand icommand = this.getCommands().get(command);
        if(icommand == null)
        {
            if(manager.executeCustomCommand(sender, command, args))
            {
                return 1;
            }
            manager.printMissingCommand(sender, command);
            return 0;
        }
        
        if(manager.hasPermission(sender, icommand.getName()))
        {
            CommandEvent e = new CommandEvent(icommand, sender, args);
            if(net.minecraftforge.common.MinecraftForge.EVENT_BUS.post(e))
            {
                if(e.getException() != null)
                {
                    com.google.common.base.Throwables.propagateIfPossible(e.getException());
                }
                return 1;
            }
            if(e.getParameters() != null)
            {
                args = e.getParameters();
            }
            this.tryExecute(sender, args, icommand, rawCommand);
        }
        else
        {
            manager.printMissingPermission(sender, icommand);
        }
        return 1;
    }

    @Override
    public List<String> getTabCompletions(ICommandSender sender, String input, @Nullable BlockPos pos)
    {
        String[] astring = input.split(" ", -1);
        String command = astring[0];
        if(astring.length == 1)
        {
            return this.getCommands().entrySet().stream()
                    .filter(e -> (CommandBase.doesStringStartWith(command, e.getKey()) && 
                            manager.hasPermission(sender, e.getKey())))
                    .map(e -> e.getKey())
                    .collect(Collectors.toList());
        }
        else if(astring.length > 1)
        {
            ICommand icommand = this.getCommands().get(command);
            if(icommand != null && manager.hasPermission(sender, icommand.getName()))
            {
                return icommand.getTabCompletions(this.getServer(), sender, dropFirstString(astring), pos);
            }
        }
        return Collections.<String>emptyList();
    }

    @Override
    public List<ICommand> getPossibleCommands(ICommandSender sender)
    {
        return this.getCommands().entrySet().stream()
                    .filter(e -> manager.hasPermission(sender, e.getKey()))
                    .map(e -> e.getValue())
                    .collect(Collectors.toList());
    }

    @Override
    public ICommand registerCommand(ICommand command)
    {
        String s = null;
        out: for(StackTraceElement e : Thread.currentThread().getStackTrace())
        {
            String name = e.getClassName();
            if(events == null)
            {
                events = new LinkedList<>();
            }
            for(String start : events)
            {
                if(name.startsWith(start))
                {
                    s = name;
                    break out;
                }
            }
        }
        if(s != null)
        {
            manager.onRegisterCommand(command, s);
        }
        return super.registerCommand(command);
    }
}