minecraft-kajetans-mod/src/main/java/me/km/utils/ReflectionUtils.java

package me.km.utils;

import cpw.mods.modlauncher.api.INameMappingService;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Map;
import net.minecraft.command.Commands;
import net.minecraft.entity.LivingEntity;
import net.minecraft.entity.item.ItemEntity;
import net.minecraft.entity.player.PlayerAbilities;
import net.minecraft.entity.player.ServerPlayerEntity;
import net.minecraft.entity.projectile.AbstractArrowEntity;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.management.PlayerList;
import net.minecraft.util.DamageSource;
import net.minecraft.util.FoodStats;
import net.minecraft.util.ResourceLocation;
import net.minecraft.world.IWorld;
import net.minecraftforge.common.DimensionManager;
import net.minecraftforge.fml.common.ObfuscationReflectionHelper;
import static net.minecraftforge.fml.common.ObfuscationReflectionHelper.remapName;
import org.apache.logging.log4j.LogManager;

public class ReflectionUtils 
{    
    // -----------------------------------------------------------------------------------
    // helper stuff
    // -----------------------------------------------------------------------------------
    
    private static Method getMethod(Class c, String name, Class... pars)
    {
        try
        {
            return ObfuscationReflectionHelper.findMethod(c, name, pars);
        }
        catch(Exception ex)
        {
            LogManager.getLogger().warn(name + " - " + ex);
        }
        return null;
    }
    
    public static Field getField(Class c, String field)
    {
        try
        {
            Field f = c.getDeclaredField(remapName(INameMappingService.Domain.FIELD, field));
            f.setAccessible(true);
            return f;
        }
        catch(Exception ex)
        {
            LogManager.getLogger().warn(field + " - " + ex);
        }
        return null;
    } 
    
    private static <T> void setInt(T t, Field f, int i)
    {
        try
        {
            f.setInt(t, i);
        }
        catch(SecurityException | IllegalArgumentException | IllegalAccessException | NullPointerException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
        }
    }
    
    private static <T> int getInt(T t, Field f, int error)
    {
        try
        {
            return f.getInt(t);
        }
        catch(SecurityException | IllegalArgumentException | IllegalAccessException | NullPointerException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
            return error;
        }
    }
    
    private static <T> void setFloat(T t, Field f, float fl)
    {
        try
        {
            f.setFloat(t, fl);
        }
        catch(SecurityException | IllegalArgumentException | IllegalAccessException | NullPointerException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
        }
    }
    
    private static <T> float getFloat(T t, Field f, float error)
    {
        try
        {
            return f.getFloat(t);
        }
        catch(SecurityException | IllegalArgumentException | IllegalAccessException | NullPointerException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
            return error;
        }
    }
    
    private static <T> boolean getBoolean(T t, Field f, boolean error)
    {
        try
        {
            return f.getBoolean(t);
        }
        catch(SecurityException | IllegalArgumentException | IllegalAccessException | NullPointerException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
            return error;
        }
    }
    
    public static <T> T getFieldValue(Class<T> cast, Object o, Field f)
    {
        try
        {
            return (T) f.get(o);
        }
        catch(SecurityException | IllegalAccessException | IllegalArgumentException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
            return null;
        }
    }
    
    public static void setFieldValue(Object instance, Field f, Object value)
    {
        try
        {
            f.set(instance, value);
        }
        catch(SecurityException | IllegalAccessException | IllegalArgumentException ex)
        {
            LogManager.getLogger().warn(f + " - " + ex);
        }
    }
    
    public static <T> T getFieldValue(Class<T> cast, Class c, Object instance, String field)
    {
        Field f = getField(c, field);
        if(f == null)
        {
            return null;
        }
        return getFieldValue(cast, instance, f);
    }    
    
    // -----------------------------------------------------------------------------------
    // food stats
    // -----------------------------------------------------------------------------------
    
    private final static Field FOOD_EXHAUSTION_LEVEL = getField(FoodStats.class, "field_75126_c"); // foodExhaustionLevel
    
    public static void setExhaustion(FoodStats stats, float f)
    {
        setFloat(stats, FOOD_EXHAUSTION_LEVEL, f);
    }
    
    public static float getExhaustion(FoodStats stats)
    {
        return getFloat(stats, FOOD_EXHAUSTION_LEVEL, 0);
    }
    
    private final static Field FOOD_SATURATION_LEVEL = getField(FoodStats.class, "field_75125_b"); // foodSaturationLevel
    
    public static void setSaturation(FoodStats stats, float f)
    {
        setFloat(stats, FOOD_SATURATION_LEVEL, f);
    }   
    
    // -----------------------------------------------------------------------------------
    // player stats
    // -----------------------------------------------------------------------------------
    
    private final static Field FLY_SPEED = getField(PlayerAbilities.class, "field_75096_f"); // flySpeed
    
    public static void setFlySpeed(PlayerAbilities cap, float f)
    {
        setFloat(cap, FLY_SPEED, f);
    }
    
    private final static Field WALK_SPEED = getField(PlayerAbilities.class, "field_75097_g"); // walkSpeed
    
    public static void setWalkSpeed(PlayerAbilities cap, float f)
    {
        setFloat(cap, WALK_SPEED, f);
    }
    
    // -----------------------------------------------------------------------------------
    // PlayerList
    // -----------------------------------------------------------------------------------
    
    private final static Method SET_GAMETYPE = getMethod(PlayerList.class, "func_72381_a", 
            ServerPlayerEntity.class, ServerPlayerEntity.class, IWorld.class); // setPlayerGameTypeBasedOnOther
    
    public static void setPlayerGameTypeBasedOnOther(PlayerList pl, ServerPlayerEntity target, ServerPlayerEntity source, IWorld worldIn)
    {
        try
        {
            SET_GAMETYPE.invoke(pl, target, source, worldIn);
        }
        catch(IllegalAccessException | IllegalArgumentException | InvocationTargetException ex)
        {
            LogManager.getLogger().warn("setPlayerGameTypeBasedOnOther - " + ex);
        }
    }
    
    // -----------------------------------------------------------------------------------
    // random field gets
    // -----------------------------------------------------------------------------------
    
    private final static Field TIME_IN_GROUND = getField(AbstractArrowEntity.class, "field_184552_b"); // timeInGround
    
    public static int getArrowTimeInGround(AbstractArrowEntity arrow)
    {
        return getInt(arrow, TIME_IN_GROUND, 0);
    }
    
    private final static Field ENTITY_ITEM_AGE = getField(ItemEntity.class, "field_70292_b"); // age
    
    public static int getAge(ItemEntity item)
    {
        return getInt(item, ENTITY_ITEM_AGE, 0);
    }
    
    public static void setAge(ItemEntity item, int age)
    {
        setInt(item, ENTITY_ITEM_AGE, age);
    }
    
    // -----------------------------------------------------------------------------------
    // minecraft server 
    // -----------------------------------------------------------------------------------
    
    private final static Field COMMAND_MANAGER = getField(MinecraftServer.class, "field_195579_af"); // commandManager
    
    public static void setCommandManager(MinecraftServer server, Commands manager)
    {
        setFieldValue(server, COMMAND_MANAGER, manager);
    }
       
    // -----------------------------------------------------------------------------------
    // DimensionManager
    // -----------------------------------------------------------------------------------
    
    private final static Field SAVED_ENTRIES = getField(DimensionManager.class, "savedEntries"); // forge name

    public static void removeDimensionSaveEntry(ResourceLocation rl)
    {
        // the map seems to be always empty ...
        getFieldValue(Map.class, null, SAVED_ENTRIES).remove(rl);
    }
    
    // -----------------------------------------------------------------------------------
    // LivingEntity stuff
    // -----------------------------------------------------------------------------------
    
    private final static Method APPLY_POTION_DAMAGE_CALCULATIONS = getMethod(
            LivingEntity.class, 
            "func_70672_c", DamageSource.class, float.class);
    
    public static float applyPotionDamageCalculations(LivingEntity liv, DamageSource ds, float damage)
    {
        try
        {
            return (float) APPLY_POTION_DAMAGE_CALCULATIONS.invoke(liv, ds, damage);
        }
        catch(IllegalAccessException | IllegalArgumentException | InvocationTargetException ex)
        {
            LogManager.getLogger().warn("applyPotionDamageCalculations - " + ex);
            return damage;
        }
    }
    
    private final static Method DAMAGE_ARMOR = getMethod(
            LivingEntity.class, 
            "func_70675_k", float.class);
    
    public static void damageArmor(LivingEntity liv, float damage)
    {
        try
        {
            DAMAGE_ARMOR.invoke(liv, damage);
        }
        catch(IllegalAccessException | IllegalArgumentException | InvocationTargetException ex)
        {
            LogManager.getLogger().warn("damageArmor - " + ex);
        }
    }
}