Useful Pets Level

public class Level
{
    public static final int MAX_LEVEL = 25;

    public static int getLevelExperienceRequirements( int level )
    {
        level -= 1;
        return ( UsefulPets.config.get( "general", "hardLevelReqs_Items", false ).getBoolean( false ) ) ? ( int )( level * 1.5f ) : ( level / 2 );
    }

    public static List< ItemStack > getLevelItemRequirements( int level )
    {
        List< ItemStack > list = new ArrayList< ItemStack >();

        level -= 1;

        if ( UsefulPets.config.get( "general", "hardLevelReqs_Items", false ).getBoolean( false ) )
        {
            int coal = level;
            int iron = ( level - 3 ) * 2;
            int redstone = ( level - 7 ) * 2;
            int gold = ( level - 12 ) * 2;
            int diamondCount = ( level - 16 ) * 3;

            list.add( new ItemStack( coal_block, coal ) );
            if ( level >= 4 )
            {
                list.add( new ItemStack( iron_ingot, iron ) );
            }
            if ( level >= 8 )
            {
                list.add( new ItemStack( redstone_block, redstone ) );
            }
            if ( level >= 13 )
            {
                list.add( new ItemStack( gold_ingot, gold ) );
            }
            if ( level >= 17 )
            {
                list.add( new ItemStack( diamond, diamondCount ) );
            }
        }
        else
        {
                 if ( level <= 5  ) list.add( new ItemStack( coal_block ) );
            else if ( level <= 20  ) list.add( new ItemStack( iron_ingot, 5 ) );
            else if ( level <= 15 ) list.add( new ItemStack( redstone_block ) );
            else if ( level <= 20 ) list.add( new ItemStack( gold_ingot, 5 ) );
            else if ( level <= 25 ) list.add( new ItemStack( diamond ) );
        }

        return list;
    }
}