/**
* Detecting factory, based on the position of the base. The rails must be one block above and the
* sign if it exists must be one or two blocks below. Signs are guaranteed to be signs (unless
* they're null) and rails are guaranteed to be rails.
*
* @param base the block on which the rails sit; the type of this block is what determines the
* mechanism type.
*/
public static CartMechanismBlocks findByBase(Block base) throws InvalidMechanismException {
if (!BlockType.isRailBlock(base.getFace(BlockFace.UP, 1).getTypeId()))
throw new InvalidMechanismException("could not find rails.");
if (SignUtil.isSign(base.getFace(BlockFace.DOWN, 1).getTypeId())) {
return new CartMechanismBlocks(
base.getFace(BlockFace.UP, 1), base, base.getFace(BlockFace.DOWN, 1));
} else if (SignUtil.isSign(base.getFace(BlockFace.DOWN, 2).getTypeId())) {
return new CartMechanismBlocks(
base.getFace(BlockFace.UP, 1), base, base.getFace(BlockFace.DOWN, 2));
}
return new CartMechanismBlocks(base.getFace(BlockFace.UP, 1), base, null);
}
/**
* Detecting factory, based on the position of the rails. The base must be one block below and the
* sign if it exists must be two or three blocks below. Signs are guaranteed to be signs (unless
* they're null) and rails are guaranteed to be rails.
*
* <p>This is the most important constructor, since it is the one invoked when processing cart
* move events.
*
* @param rail the block containing the rails.
*/
public static CartMechanismBlocks findByRail(Block rail) throws InvalidMechanismException {
if (!BlockType.isRailBlock(rail.getTypeId()))
throw new InvalidMechanismException("rail argument must be a rail!");
if (SignUtil.isSign(rail.getFace(BlockFace.DOWN, 2).getTypeId())) {
return new CartMechanismBlocks(
rail, rail.getFace(BlockFace.DOWN, 1), rail.getFace(BlockFace.DOWN, 2));
} else if (SignUtil.isSign(rail.getFace(BlockFace.DOWN, 3).getTypeId())) {
return new CartMechanismBlocks(
rail, rail.getFace(BlockFace.DOWN, 1), rail.getFace(BlockFace.DOWN, 3));
}
return new CartMechanismBlocks(rail, rail.getFace(BlockFace.DOWN, 1), null);
}
/**
* Detecting factory, based on the position of the sign. The base must be one or two blocks above
* and the rails an additional block above the base. Signs are guaranteed to be signs and rails
* are guaranteed to be rails.
*
* @param sign the block containing the sign that gives additional configuration to the mechanism.
*/
public static CartMechanismBlocks findBySign(Block sign) throws InvalidMechanismException {
if (!SignUtil.isSign(sign))
throw new InvalidMechanismException("sign argument must be a sign!");
if (BlockType.isRailBlock(sign.getFace(BlockFace.UP, 2).getTypeId())) {
return new CartMechanismBlocks(
sign.getFace(BlockFace.UP, 2), sign.getFace(BlockFace.UP, 1), sign);
} else if (BlockType.isRailBlock(sign.getFace(BlockFace.UP, 3).getTypeId())) {
return new CartMechanismBlocks(
sign.getFace(BlockFace.UP, 3), sign.getFace(BlockFace.UP, 2), sign);
}
throw new InvalidMechanismException("could not find rails.");
}
/**
* Detecting factory; defers to one of the other three specific detecting factories based on
* whether the given unknown block appears to be a sign, rail, or base.
*
* @param unknown the block to examine.
*/
public static CartMechanismBlocks find(Block unknown) throws InvalidMechanismException {
final int ti = unknown.getTypeId();
if (SignUtil.isSign(ti)) return findBySign(unknown);
else if (BlockType.isRailBlock(ti)) return findByRail(unknown);
else return findByBase(unknown);
}
