package ic2.api;

import net.minecraft.tileentity.TileEntity;
import net.minecraftforge.common.ForgeDirection;

/**
 * Represents the 6 possible directions along the axis of a block.
 */
public enum Direction
{
	/**
	 * -X
	 */
	XN(0),
	/**
	 * +X
	 */
	XP(1),

	/**
	 * -Y
	 */
	YN(2), // MC-Code starts with 0 here
	/**
	 * +Y
	 */
	YP(3), // 1...

	/**
	 * -Z
	 */
	ZN(4),
	/**
	 * +Z
	 */
	ZP(5);

	Direction(int dir)
	{
		this.dir = dir;
	}

	/*
	 * public CoordinateTuple ApplyToCoordinates(CoordinateTuple coordinates) { CoordinateTuple ret
	 * = new CoordinateTuple(coordinates);
	 * 
	 * ret.coords[dir/2] += GetSign();
	 * 
	 * return ret; }
	 */

	/**
	 * Get the tile entity next to a tile entity following this direction.
	 * 
	 * @param tileEntity tile entity to check
	 * @return Adjacent tile entity or null if none exists
	 */
	public TileEntity applyToTileEntity(TileEntity tileEntity)
	{
		int coords[] = { tileEntity.xCoord, tileEntity.yCoord, tileEntity.zCoord };

		coords[dir / 2] += getSign();

		if (tileEntity.worldObj != null && tileEntity.worldObj.blockExists(coords[0], coords[1], coords[2]))
		{
			return tileEntity.worldObj.getBlockTileEntity(coords[0], coords[1], coords[2]);
		}
		else
		{
			return null;
		}
	}

	/**
	 * Get the inverse of this direction (XN -> XP, XP -> XN, etc.)
	 * 
	 * @return Inverse direction
	 */
	public Direction getInverse()
	{
		int inverseDir = dir - getSign();

		for (Direction direction : directions)
		{
			if (direction.dir == inverseDir)
				return direction;
		}

		return this;
	}

	/**
	 * Convert this direction to a Minecraft side value.
	 * 
	 * @return Minecraft side value
	 */
	public int toSideValue()
	{
		return (dir + 4) % 6;
	}

	/**
	 * Determine direction sign (N for negative or P for positive).
	 * 
	 * @return -1 if the direction is negative, +1 if the direction is positive
	 */
	private int getSign()
	{
		return (dir % 2) * 2 - 1;
	}

	public ForgeDirection toForgeDirection()
	{
		return ForgeDirection.getOrientation(toSideValue());
	}

	private int dir;
	public static final Direction[] directions = Direction.values();
}