minecraft-kajetans-mod/src/main/java/me/km/permissions/PermissionManager.java

package me.km.permissions;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.UUID;
import net.minecraft.command.CommandSource;
import net.minecraft.entity.Entity;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.DEDICATED_SERVER)
public class PermissionManager
{
    private final HashMap<UUID, ArrayList<Integer>> playerGroups = new HashMap<>();
    private final ArrayList<HashSet<String>> stringGroupPerms = new ArrayList<>();
    private final HashSet<String> otherGroup = new HashSet<>();
    private final boolean debug;
    
    public PermissionManager(boolean debug) 
    {
        this.debug = debug;
        addGroups();
    }

    public void clear()
    {
        playerGroups.clear();
        stringGroupPerms.clear();
        addGroups();
    }
    
    private void addGroups()
    {
        stringGroupPerms.add(new HashSet<>());
        stringGroupPerms.add(otherGroup);
    }
    
    public void addOtherGroupPermission(String perm)
    {
        otherGroup.add(perm);
    }
    
    // -------------------------------------------------------------------------
    // Permission-Check
    // -------------------------------------------------------------------------
    
    private final static UUID MARVINIUS = UUID.fromString("e41b5335-3c74-46e9-a6c5-dafc6334a477");
    private final static UUID KAJETANJOHANNES = UUID.fromString("51e240f9-ab10-4ea6-8a5d-779319f51257");
    
    public boolean hasPermission(Entity ent, String perm) 
    {
        return hasPermission(ent.getUniqueID(), perm);
    }
    
    public boolean hasPermission(UUID uuid, String perm) 
    {
        if(debug)
        {
            return true;
        }
        if(perm.equals("script"))
        {
            if(uuid.equals(MARVINIUS) || uuid.equals(KAJETANJOHANNES))
            {
                return true;
            }
        }
        ArrayList<Integer> groups = playerGroups.get(uuid);
        if(groups == null)
        {
            if(!stringGroupPerms.isEmpty())
            {
                return stringGroupPerms.get(0).contains(perm);
            }
            else
            {
                return false;
            }
        }
        return groups.stream().anyMatch(i -> stringGroupPerms.get(i).contains(perm));
    }
    
    public boolean hasPermission(CommandSource cs, String perm) 
    {
        Entity ent = cs.getEntity();
        if(ent != null)
        {
            return hasPermission(ent.getUniqueID(), perm);
        }
        return true;
    }

    // -------------------------------------------------------------------------
    // Permission-Registry
    // -------------------------------------------------------------------------
    
    public void registerPlayerGroup(UUID uuid, int id)
    {
        if(id < 0 || id >= stringGroupPerms.size())
        {
            throw new IllegalArgumentException(String.format("%d' is no valid group id", id));
        }
        ArrayList<Integer> groups = playerGroups.get(uuid);
        if(groups == null)
        {
            groups = new ArrayList<>();
            // adding default group
            groups.add(0);
            playerGroups.put(uuid, groups);
        }
        groups.add(id);
    }
    
    public boolean unregisterPlayer(UUID uuid, int id)
    {
        if(id < 0 || id >= stringGroupPerms.size())
        {
            throw new IllegalArgumentException(String.format("%d' is no valid group id", id));
        }
        ArrayList<Integer> groups = playerGroups.get(uuid);
        if(groups == null)
        {
            return false;
        }
        return groups.remove((Integer) id);
    }
    
    public void registerGroupPermission(int id, String perm)
    {
        if(perm.isEmpty())
        {
            throw new IllegalArgumentException("empty permission string");
        }
        if(id == 1)
        {
            throw new IllegalArgumentException("id 1 is reserved for worldedit");
        }
        if(id >= stringGroupPerms.size())
        {
            HashSet<String> set = new HashSet<>();
            set.add(perm);
            stringGroupPerms.add(set);
            return;
        }
        stringGroupPerms.get(id).add(perm);
    }
}