private void ExtendRight(DawgNode node, BoardTile boardTile)
{
string partialWord = node.Word;
if (boardTile == null)
{
AddWordToValidWordsIfValid(partialWord);
}
else if (boardTile.CharTile == null)
{
if (boardTile != StartingBoardTile)
{
AddWordToValidWordsIfValid(partialWord);
}
foreach (char edge in node.Edges)
{
HashSet <char> boardTileCrossChecks = GetBoardTileCrossChecks(boardTile);
if (!PlayerRack.ContainsCharTile(edge) || (boardTileCrossChecks != null && !boardTileCrossChecks.Contains(edge)))
{
continue;
}
char rackChar = PlayerRack.TakeCharTile(edge);
string partialWordPlusEdge = partialWord + rackChar.ToString();
DawgNode nextNode = GetDawgNode(partialWordPlusEdge);
BoardTile nextBoardTile = Board.GetBoardTileAtCoordinates(boardTile.X, boardTile.Y + 1);
SetBoardTileCrossChecks(nextBoardTile);
ExtendRight(nextNode, nextBoardTile);
PlayerRack.AddCharTile(rackChar);
}
}
else
{
char charOnBoardTile = boardTile.CharTile.Letter;
if (!node.Edges.Contains(charOnBoardTile))
{
return;
}
string partialWordPlusEdge = partialWord + charOnBoardTile.ToString();
DawgNode nextNode = GetDawgNode(partialWordPlusEdge);
BoardTile nextBoardTile = Board.GetBoardTileAtCoordinates(boardTile.X, boardTile.Y + 1);
SetBoardTileCrossChecks(nextBoardTile);
ExtendRight(nextNode, nextBoardTile);
}
}
private void LeftPart(DawgNode node, int limit, BoardTile anchor)
{
ExtendRight(node, anchor);
if (LeftPartIsAlreadyProvided || limit <= 0)
{
return;
}
foreach (char edge in node.Edges)
{
if (!PlayerRack.ContainsCharTile(edge))
{
continue;
}
char rackChar = PlayerRack.TakeCharTile(edge);
string partialWord = node.Word;
string partialWordPlusEdge = partialWord + rackChar.ToString();
DawgNode nextNode = GetDawgNode(partialWordPlusEdge);
LeftPart(nextNode, limit - 1, anchor);
PlayerRack.AddCharTile(rackChar);
}
}
public List <BoardWord> GetPossibleMoves(BoardTile anchor, IPlayerRack playerRack)
{
ValidWords = new List <BoardWord>();
PlayerRack = playerRack;
StartingBoardTile = anchor;
BoardTilesAndTheirCrossChecks = new Dictionary <BoardTile, HashSet <char> >();
HorizontalBoardWord wordToTheLeftOfAnchor = BoardWordRetriever.GetHorizontalWordTilesAtCoordinates(StartingBoardTile.X, StartingBoardTile.Y - 1);
string partialWord = wordToTheLeftOfAnchor?.GetWord() ?? "";
LeftPartIsAlreadyProvided = partialWord.Length > 0;
BoardTilesAndTheirCrossChecks.Add(StartingBoardTile, BoardCrossCheckCollector.GetCrossChecksForBoardTile(StartingBoardTile));
BoardAnchorCollector boardAnchorCollector = new();
BoardTileCollection boardAnchors = boardAnchorCollector.GetAnchors(Board);
DawgNode node = GetDawgNode(partialWord);
BoardNonAnchorTileCounter boardNonAnchorTileCounter = new(Board);
int limit = boardNonAnchorTileCounter.GetNumberOfNonAnchorTilesToTheLeftOfABoardTile(StartingBoardTile, boardAnchors);
LeftPart(node, limit, anchor);
return(ValidWords);
}