configs and projectPath

In the last few commits the problem occured
that absolute paths are needed for correct
and unambiguous locations for binary files
or the database.
For the compiler arguments the problem is now
solved with an automatic script, that creates
the absolute paths automatically for different
systems.
The database path is now specified by calling
a new function, that finds the root of the
project followed by a relative path.

.gitignore

@@ -0,0 +1,6 @@
+secret.nim
+nim.cfg
+
+bin
+htmldocs
+ressources

README.md

@@ -1,30 +1,122 @@
 # ychess
 
-Attention: **The Chess engine is not finished yet.**
+![ychess-logo](./art/ychess.png)
-
-![ychess-logo](ychess.png)
 
 ychess is a chess implementation and engine written in nim.
 
-## Usage
+## Usage and contribution
 
-Simply download the code and run `nim c -r game.nim`.
+For the following subsections to work properly you need to have `nim.cfg` files
-You can now play a 1v1 hotseat game of chess in the commandline.
+so you don't need to pass all compiler arguments manually.
+To automatically create the config files run `nim c -r createCfg.nim` from the
+root directory of the project.
 
-## Testing
+### Todos
 
-Testing is done by `einheit` by [jyapayne](https://github.com/jyapayne/einheit).
+[TODO.md](./TODO.md) contains a list of features that are planned.
-All legal chess moves are implemented in `chess.nim` and tested by the TestSuite
-in `test.nim`.
-You can simply run the tests with `nim c -r test.nim`.
 
-## Documentation
+### Command line
+
+To play chess in the commandline simply download the code (or clone the
+repository) and run `nim c -r game.nim`.
+You can either play the 1v1 hotseat mode or a single player mode vs the engine.
+
+### Lichess
+
+ychess uses the lichess api to make playing more convenient.
+An instance of the engine occasionally plays on
+[lichess](https://lichess.org/@/tiyn-ychess).
+To get into the whitelist just write a ingame message to the account.
+
+If you want to create an instance on lichess yourself you need to set a api
+token.
+This is done in `src/engine/secret.nim`.
+It should have the following structure:
+
+```nim
+let api_token* = "<lichess api token for bot>"
+```
+
+Following that you will want to set your username into the whitelist in
+`src/engine/lichessBridge.nim`.
+After that you can start the lichess bot by running
+`nim c -r src/engine/lichessBridge.nim`.
+
+## Project Structure
+
+- `art` - contains pictures and arts not used in the code.
+- `bin` - is not pushed to the git repository but contains all binaries and will
+be created if you compile a program.
+- `htmldocs` - is not pushed to the git repository but contains all
+automatically generated documentation.
+- `ressources` - is not pushed to the git repository but contains all
+the data used in source code but not being source code itself (e.g. databases).
+- `src` - is the root folder for all programs except tests.
+- `tests` - contains all tests.
+
+### Documentation
 
 Documentation is written into the code via DocGen.
 For this reason it is not saved in this repository.
-To extract it into html run `nim doc --project --index:on --outdir:htmldocs game.nim`
+To extract it into html (assuming you want the documentation for `game.nim`)
+run `nim doc --project --index:on --outdir:htmldocs game.nim`.
+
+## Additional Documentation
+
+### Moves
+
+Moves are read from the commandline as
+[pure coordinate notation](https://www.chessprogramming.org/Algebraic_Chess_Notation#Pure_coordinate_notation).
+The inner program will convert this notation to a move-tuple.
 
 ### Board Representation
 
 Due to easier off the board checking a
 [10x12](https://www.chessprogramming.org/10x12_Board) board is used.
+
+### Engine
+
+The engine uses a simple implementation of the
+[NegaMax](https://www.chessprogramming.org/NegaMax)-algorithm with
+[Alpha-Beta-Pruning](https://www.chessprogramming.org/Alpha-Beta#Negamax_Framework).
+For the evaluation function each piece has a corresponding value.
+Additionally [piece-square tables](https://www.chessprogramming.org/Piece-Square_Tables)
+are used.
+
+### Code Style Guide
+
+Make sure to take a look at the
+[official nim style guide](https://nim-lang.org/docs/nep1.html).
+All conventions should be applied to this code.
+
+Additionally there are a bunch of steps to make the code more consistent.
+
+#### Constants
+
+Constants should start with an uppercase letter but shouldn't be written in all
+caps (`const FooBar = 2`).
+
+#### Whitespaces
+
+Basic arithmetic operations should be surrounded by spaces for example: `1 + 3`.
+This however is not true for negation of a single value (`-1`) or if the
+arithmetic operation is done inside array brackets or in iterators (`a+1..3`,
+`a[c+3]`).
+
+#### Function calls
+
+Determining the length of a string, array, etc should not be done via a function
+(`len(array)`) but by appending it like `array.len`.
+In the same style function calls should be done (`chess.convertToFen()` instead
+of `convertToFen(chess)`).
+This however is not true if the function takes a first argument that is not an
+abstract datatype like the joinPath function (all the parameters are strings).
+
+#### booleans and logic
+
+If statements should not contain outer brackets.
+In some cases (especially concatenations of `and` and `or`) inner brackets are
+useful to increase readability in complexer logic formulas.
+
+When assigning booleans with logical formulas outer brackets are expected
+(`var boolVar = (1 == 1)`).

TODO.md

@@ -0,0 +1,7 @@
+# TODO
+
+This is a list of features that are to be implemented.
+
+- Opening Book
+- Endgame Table
+- Docker integration

createCfg.nim

@@ -0,0 +1,13 @@
+import os
+
+import src/project
+
+let projDir = getProjRootDir()
+var tmpPath: string
+
+for dir in ["src", "tests"]:
+  tmpPath = joinPath(projDir, dir)
+  var f = open(joinPath(tmpPath, "nim.cfg"), fmWrite)
+  f.writeLine("--outdir:\"" & joinPath(projDir, "bin", dir) & "\"")
+  f.writeLine("--path:\"" & joinPath(projDir, "src") & "\"")
+  f.close()

src/engine/engine.nim

@@ -0,0 +1,191 @@
+import algorithm
+
+import chess
+
+type
+  MoveTree = object
+    ## `Movetree` is a visualization for possible moves.
+    chess: Chess
+    evaluation: float
+    children: seq[Movetree]
+
+const
+  PawnVal = 100          ## `PawnVal` is the engines value for a pawn.
+  KnightVal = 310        ## `KnightVal` is the engines value for a knight.
+  BishopVal = 330        ## `BishopVal` is the engines value for a bishop.
+  RookVal = 500          ## `RookVal` is the engines value for a rook.
+  QueenVal = 900         ## `QueenVal` is the engines value for a queen.
+  CheckmateVal = -100000 ## `CheckmateVal` is the engines value for a checkmate.
+  DrawVal = 0            ## `DrawVal` is the engines value for a draw.
+  HiVal = 10000          ## `LoVal` is a value always lower than  any evaluation.
+  LoVal = -HiVal         ## `LoVal` is a value always lower than  any evaluation.
+  pawnTable = [
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 5, 10, 10, -20, -20, 10, 10, 5, 0,
+    0, 5, -5, -10, 0, 0, -10, -5, 5, 0,
+    0, 0, 0, 0, 20, 20, 0, 0, 0, 0,
+    0, 5, 5, 10, 25, 25, 10, 5, 5, 0,
+    0, 10, 10, 20, 30, 30, 20, 10, 10, 0,
+    0, 50, 50, 50, 50, 50, 50, 50, 50, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  ]                     ## `pawnTable` is the piece-square table for pawns.
+  knightTable = [
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, -50, -40, -30, -30, -30, -30, -40, -50, 0,
+    0, -40, -20, 0, 5, 5, 0, -20, -40, 0,
+    0, -30, 0, 10, 15, 15, 10, 0, -30, 0,
+    0, -30, 5, 15, 20, 20, 15, 5, -30, 0,
+    0, -30, 0, 15, 20, 20, 15, 0, -30, 0,
+    0, -30, 5, 10, 15, 15, 10, 5, -30, 0,
+    0, -40, -20, 0, 0, 0, 0, -20, -40, 0,
+    0, -50, -40, -30, -30, -30, -30, -40, -50, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  ]                     ## `knightTable` is the piece-square table for pawns.
+  bishopTable = [
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, -20, -10, -10, -10, -10, -10, -10, -20, 0,
+    0, -10, 5, 0, 0, 0, 0, 5, -10, 0,
+    0, -10, 10, 10, 10, 10, 10, 10, -10, 0,
+    0, -10, 0, 10, 10, 10, 10, 0, -10, 0,
+    0, -10, 5, 5, 10, 10, 5, 5, -10, 0,
+    0, -10, 0, 5, 10, 10, 5, 0, -10, 0,
+    0, -10, 0, 0, 0, 0, 0, 0, -10, 0,
+    0, -20, -10, -10, -10, -10, -10, -10, -20, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  ]                     ## `bishopTable` is the piece-square table for pawns.
+  rookTable = [
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 5, 5, 0, 0, 0, 0,
+    0, -5, 0, 0, 0, 0, 0, 0, -5, 0,
+    0, -5, 0, 0, 0, 0, 0, 0, -5, 0,
+    0, -5, 0, 0, 0, 0, 0, 0, -5, 0,
+    0, -5, 0, 0, 0, 0, 0, 0, -5, 0,
+    0, -5, 0, 0, 0, 0, 0, 0, -5, 0,
+    0, 5, 10, 10, 10, 10, 10, 10, 5, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  ]                     ## `rookTable` is the piece-square table for pawns.
+  queenTable = [
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, -20, -10, -10, -5, -5, -10, -10, -20, 0,
+     0, -10, 0, 0, 0, 0, 5, 0, -10, 0,
+     0, -10, 0, 5, 5, 5, 5, 0, -10, 0,
+     0, -10, 0, 5, 5, 5, 5, 0, -10, 0,
+     0, -10, 0, 5, 5, 5, 5, 0, -10, 0,
+     0, -10, 0, 5, 5, 5, 5, 0, -10, 0,
+     0, -10, 0, 0, 0, 0, 0, 0, -10, 0,
+     0, -20, -10, -10, -5, -5, -10, -10, -20, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+    ]                   ## `queenTable` is the piece-square table for pawns.
+  kingTable = [
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, 20, 30, 10, 0, 0, 10, 30, 20, 0,
+     0, 20, 20, 0, 0, 0, 0, 20, 20, 0,
+     0, -10, -20, -20, -20, -20, -20, -20, -10, 0,
+     0, -20, -30, -30, -40, -40, -30, -30, -20, 0,
+     0, -30, -40, -40, -50, -50, -40, -40, -30, 0,
+     0, -30, -40, -40, -50, -50, -40, -40, -30, 0,
+     0, -30, -40, -40, -50, -50, -40, -40, -30, 0,
+     0, -30, -40, -40, -50, -50, -40, -40, -30, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+     0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+    ]                    ## `kingTable` is the piece-square table for pawns.
+
+proc pieceEval(chess: Chess): int =
+  ## Returns the evaluation of existing pieces on the `board`
+  var evaluation: int
+  for ind, piece in chess.board:
+    let tmpEval = case piece:
+      of WPawn:
+        ord(Color.White) * PawnVal + ord(Color.White) * pawnTable[ind]
+      of WKnight:
+        ord(Color.White) * KnightVal + ord(Color.White) * knightTable[ind]
+      of WBishop:
+        ord(Color.White) * BishopVal + ord(Color.White) * bishopTable[ind]
+      of WRook:
+        ord(Color.White) * RookVal + ord(Color.White) * rookTable[ind]
+      of WQueen:
+        ord(Color.White) * QueenVal + ord(Color.White) * queenTable[ind]
+      of WKing:
+        ord(Color.White) * kingTable[ind]
+      of BPawn:
+        ord(Color.Black) * PawnVal + ord(Color.Black) * pawnTable.reversed[ind]
+      of BKnight:
+        ord(Color.Black) * KnightVal + ord(Color.Black) * knightTable.reversed[ind]
+      of BBishop:
+        ord(Color.Black) * BishopVal + ord(Color.Black) * bishopTable.reversed[ind]
+      of BRook:
+        ord(Color.Black) * RookVal + ord(Color.Black) * rookTable.reversed[ind]
+      of BQueen:
+        ord(Color.Black) * QueenVal + ord(Color.Black) * queenTable.reversed[ind]
+      of BKing:
+        ord(Color.White) * kingTable.reversed[ind]
+      else:
+        DrawVal
+    evaluation += tmpEval
+  return evaluation
+
+proc evaluate(chess: Chess): int =
+  ## Returns a complete evaluation of a `chess` with player `toMove` about to make
+  ## a move.
+  var evaluation: int
+  if chess.isCheckmate(chess.toMove):
+    evaluation = ord(chess.toMove) * CheckmateVal
+  if chess.isStalemate(chess.toMove):
+    evaluation = DrawVal
+  else:
+    evaluation = chess.pieceEval()
+    if chess.isDrawClaimable():
+      if chess.toMove == Color.White:
+        evaluation = max(DrawVal, evaluation)
+      else:
+        evaluation = min(DrawVal, evaluation)
+  return evaluation
+
+proc negaMax(chess: Chess, depth: int, a: int, b: int): int =
+  ## Return the value of a given `chess` with `depth` and `a` and `b` for alpha-beta
+  ## pruning.
+  var alpha = a
+  var beta = b
+  if depth <= 0 or chess.isCheckmate(chess.toMove) or chess.isStalemate(chess.toMove):
+    return chess.evaluate()
+  let possibleMoves = chess.genLegalMoves(chess.toMove)
+  for move in possibleMoves:
+    var tmpChess = chess
+    tmpChess.checkedMove(move)
+    var tmpVal = -negaMax(tmpChess, depth - 1, -beta, -alpha)
+    if tmpVal >= beta:
+      return beta
+    if tmpVal > alpha:
+      alpha = tmpVal
+  return alpha
+
+proc bestMove*(chess: Chess, depth: int): Move =
+  ## Generate a MoveTree of a `chess` with a given `depth`, run negaMax and return
+  ## the best evaluated move.
+  var moves = chess.genLegalMoves(chess.toMove)
+  var bestMove: Move
+  var bestEval: int
+  bestEval = LoVal
+  for move in moves:
+    var tmpChess = chess
+    tmpChess.checkedMove(move)
+    var tmpEval = -tmpChess.negaMax(depth, LoVal, HiVal)
+    echo("move:", moveToNotation(move, tmpChess.board), "; eval:", tmpEval)
+    if tmpEval > bestEval:
+      bestEval = tmpEval
+      bestMove = move
+  return bestMove

src/engine/lichessBridge.nim

@@ -0,0 +1,66 @@
+import nimpy
+import asyncnet, asyncdispatch
+
+import chess
+import engine/secret
+import engine/engine
+
+let berserk = pyImport("berserk")
+
+var session = berserk.TokenSession(secret.api_token)
+var client = berserk.Client(session = session)
+
+let engineID = "tiyn-ychess"
+let engineDifficulty = 2
+let toAccept = ["tiynger"]
+
+
+proc playLichessGame(id: string) {.async.} =
+  ## Plays a lichess game with `id` asynchronously.
+  var color: Color
+  var chess = initChess()
+  for event in client.bots.stream_game_state(id):
+    echo(event)
+    if $event["type"] in ["gameState", "gameFull"]:
+      var movesString: PyObject
+      if $event["type"] == "gameFull":
+        echo("gameFull received")
+        movesString = event["state"]["moves"]
+        if $event["white"]["id"] == engineID:
+          color = Color.White
+        if $event["black"]["id"] == engineID:
+          color = Color.Black
+      else:
+        echo("gameState received")
+        movesString = event["moves"]
+      if $movesString != "":
+        var moves = movesString.split(" ")
+        chess.checkedMove(notationToMove($moves[-1], chess.toMove))
+        chess.echoBoard(chess.toMove)
+      if chess.toMove == color:
+        echo("engine has to make a move")
+        var bestMove = moveToNotation(chess.bestMove(engineDifficulty), chess.board)
+        echo(bestMove)
+        discard client.bots.make_move(id, bestMove)
+
+proc acceptChallenge(whiteList: openArray[string]): void =
+  ## Accepts a challenge of users in a `whiteList` and starts the
+  ## game process for each.
+  var events = client.bots.stream_incoming_events()
+  for event in events:
+    echo(event)
+    if $event["type"] == "challenge":
+      var challenger = $event["challenge"]["challenger"]["id"]
+      var id = $event["challenge"]["id"]
+      var speed = $event["challenge"]["speed"]
+      if challenger in whiteList and speed == "correspondence":
+        echo("challenge of ", challenger, " whiteList: ", id)
+        discard client.bots.accept_challenge(id)
+        discard playLichessGame($event["challenge"]["id"])
+      else:
+        discard client.bots.decline_challenge(id)
+        echo("challenge of ", challenger, " whiteList: ", id)
+
+
+when isMainModule:
+  acceptChallenge(toAccept)

src/engine/openingBook.nim

@@ -0,0 +1,256 @@
+import db_sqlite
+import sequtils
+import strutils
+import sugar
+import tables
+import os
+
+include chess
+
+import secret
+import project
+
+type
+  BookMove* = object
+    ## `PossibleMove` capsulates a possible moves in a position with additional
+    ## statistics.
+    fen*: string # `fen` is the fen string of a position.
+    move*: string # `move` describes a move in pure coordinate notation.
+    white*: int # `white` is the number of game white won from this position.
+    black*: int # `black` is the number of game black won from this position.
+    draw*: int # `draw` is the number of game drawn from this position.
+    rating*: int # `rating` is the average rating of the player to move.
+
+
+let dbConn = joinPath(getProjRootDir(), "ressources/openings.db")
+let dbUser = ""
+let dbPasswd = ""
+let dbName = ""
+
+let tableName = "posmoves"
+
+proc initDB(): void =
+  ## Initialize the database with a table if it doesnt currently exist.
+  let db = open(dbConn, dbUser, dbPasswd, dbName)
+  db.exec(sql"""CREATE TABLE IF NOT EXISTS ? (
+                   fen    VARCHAR(100) NOT NULL,
+                   move   VARCHAR(6) NOT NULL,
+                   white  INTEGER NOT NULL,
+                   black  INTEGER NOT NULL,
+                   draw   INTEGER NOT NULL,
+                   rating INTEGER NOT NULL,
+                   PRIMARY KEY (fen, move)
+                )""", tableName)
+  db.close()
+  echo("Database initialization done.")
+
+proc storeMove(fen: string, move: string, white: bool, black: bool, draw: bool,
+    rating: int): void =
+  ## Store a possible `move` done by a player with `rating` (0 for unknown)
+  ## in a position described by `fen`.
+  ## The result of the game is described by `white`, `black` and `draw`.
+  let db = open(dbConn, dbUser, dbPasswd, dbName)
+  var query = """
+    INSERT INTO ? (fen, move, white, black, draw, rating)
+    VALUES (?, ?, ?, ?, ?, ?)
+    ON CONFLICT(fen, move) DO UPDATE SET
+  """
+  if not rating == 0:
+    query &= "rating = ((rating * (black + white + draw)) + ?) / (black + white + draw + 1),"
+  if white:
+    query &= "white = white + 1"
+  elif black:
+    query &= "black = black + 1"
+  else:
+    query &= "draw = draw + 1"
+  db.exec(sql(query), tableName, fen, move, int(white), int(black), int(draw),
+      rating, rating)
+  db.close()
+  echo("inserted (", join([fen, move, $white, $black, $draw, $rating], ", "),
+      ") into ", tableName)
+
+proc loadMove*(fen: string): seq[BookMove] =
+  ## Load all possible moves possible in a given position described by `fen`
+  ## from the database. Format moves as a BookMove object.
+  let db = open(dbConn, dbUser, dbPasswd, dbName)
+  let res = db.getAllRows(sql """SELECT move, white, black, draw, rating
+                            FROM ?
+                            WHERE fen == ?
+                            ORDER BY rating DESC
+                            """, tableName, fen)
+  db.close()
+  var fRes: seq[BookMove]
+  for entry in res:
+    var bookMv: BookMove
+    bookMv.fen = fen
+    bookMv.move = entry[0]
+    bookMv.white = parseInt(entry[1])
+    bookMv.black = parseInt(entry[2])
+    bookMv.draw = parseInt(entry[3])
+    bookMv.rating = parseInt(entry[4])
+    fRes.add(bookMv)
+  return fRes
+
+proc sanToPcn(sanMoves: string): string =
+  ## Convert a list of `sanMoves` to pure coordinate notation (assuming the game
+  ## starts in the standard initial position)
+  var sanMoveArr = sanMoves.replace("+").replace("x").replace("#").replace(
+      "!").replace("?").split(" ")
+  sanMoveArr.del(sanMoveArr.high)
+  var fSanMoves: string
+  var inComment: bool
+  for word in sanMoveArr:
+    if inComment:
+      if word.endsWith("}"):
+        inComment = false
+    else:
+      if word.startsWith("{"):
+        inComment = true
+        continue
+      if not word.endsWith("."):
+        fSanMoves &= word & " "
+  var revPieceChar = toSeq(PieceChar.pairs).map(y => (y[1], y[0])).toTable
+  var chess = initChess()
+  var lastChess = chess
+  let sanArr = fsanMoves.split(" ")
+  var pcnMoves: string
+  for sanMove in sanArr:
+    var start: string
+    var dest: string
+    if sanMove.isEmptyOrWhitespace:
+      continue
+    dest = sanMove[sanMove.high-1..sanMove.high]
+    if sanMove.contains("="):
+      let promotion = sanMove[sanMove.high]
+      if sanMove.len == 5:
+        let file = sanMove[0]
+        dest = sanMove[1..2] & promotion
+        if chess.toMove == Color.White:
+          start = file & "7"
+        else:
+          start = file & "2"
+      elif sanMove.len == 4:
+        dest = sanMove[0..1] & promotion
+        start = indToField(fieldToInd(dest) + ord(chess.toMove) * S)
+      chess.checkedMove(notationToMove(start & dest, chess.toMove))
+    elif "abcdefgh".contains(sanMove[0]):
+      let file = sanMove[0]
+      for rank in 1..8:
+        start = file & $rank
+        if fieldToInd(dest) in chess.genPawnDests(fieldToInd(start), chess.toMove):
+          if chess.checkedMove(notationToMove(start & dest, chess.toMove)):
+            break
+    elif sanMove.startsWith("O-O"):
+      if chess.toMove == Color.White:
+        start = "e1"
+        if sanMove.len == 3:
+          dest = "g1"
+        else:
+          dest = "c1"
+      else:
+        start = "e8"
+        if sanMove.len == 3:
+          dest = "g8"
+        else:
+          dest = "c8"
+      chess.checkedMove(notationToMove(start & dest, chess.toMove))
+    else:
+      var piece = revPieceChar[$sanMove[0]] * ord(chess.toMove)
+      if sanMove.len == 3:
+        var possibleStarts: seq[string]
+        for i, field in chess.board:
+          if field == piece:
+            possibleStarts.add(indToField(i))
+        for possibleStart in possibleStarts:
+          if chess.checkedMove(notationToMove(possibleStart & dest,
+              chess.toMove)):
+            start = possibleStart
+            break
+      elif sanMove.len == 4:
+        if sanMove[1].isDigit():
+          let rank = $sanMove[1]
+          for file in "abcdefg":
+            if chess.board[fieldToInd($file & rank)] == piece:
+              start = $file & rank
+              chess.checkedMove(notationToMove(start & dest, chess.toMove))
+              break
+          continue
+        else:
+          let file = sanMove[1]
+          for rank in 1..8:
+            if chess.board[fieldToInd(file & $rank)] == piece:
+              start = file & $rank
+              chess.checkedMove(notationToMove(start & dest, chess.toMove))
+              break
+      elif sanMove.len == 5:
+        start = sanMove[1..2]
+        dest = sanMove[3..4]
+        chess.checkedMove(notationToMove(start & dest, chess.toMove))
+    if lastChess == chess:
+      chess.echoBoard(Color.White)
+      echo("ERROR OCCURED")
+      return ""
+    pcnMoves.add(start & dest & " ")
+    lastChess = chess
+  return pcnMoves
+
+proc iterMultiPGN(fileP: string): void =
+  ## Iterate through a (multi) PGN file at `fileP` and store the games in the
+  ## opening database. This function is designed to work with multi PGN files
+  ## from lichess, but should also work for other formats (elo may be not working)
+  var sanMoves: string
+  var secondSpace: bool
+  var white: bool
+  var black: bool
+  var wElo: int
+  var bElo: int
+  var i: int
+  var chess: Chess
+  for line in lines(fileP):
+    if line.isEmptyOrWhitespace:
+      if not secondSpace:
+        secondSpace = true
+      else:
+        secondSpace = false
+        chess = initChess()
+        for move in sanToPcn(sanMoves).split(" "):
+          var rating = 0
+          if chess.toMove == Color.White:
+            rating = wElo
+          else:
+            rating = bElo
+          storeMove(chess.convertToFen(), move, white, black, not white and
+              not black, rating)
+          chess.checkedMove(notationToMove(move, chess.toMove))
+        i += 1
+        sanMoves = ""
+        white = false
+        black = false
+        wElo = 0
+        bElo = 0
+        if i == 1000:
+          return
+    if line.startsWith("["):
+      if line.contains("Result "):
+        if line.contains("1-0"):
+          white = true
+        elif line.contains("0-1"):
+          black = true
+      elif line.contains("WhiteElo"):
+        var eloStr = line.replace("[WhiteElo \"").replace("\"]")
+        if eloStr != "?":
+          wElo = parseInt(eloStr)
+        else:
+          wElo = 0
+      elif line.contains("BlackElo"):
+        var eloStr = line.replace("[BlackElo \"").replace("\"]")
+        if eloStr != "?":
+          bElo = parseInt(eloStr)
+        else:
+          bElo = 0
+    else:
+      sanMoves &= line
+
+when isMainModule:
+  initDB()
+  #iterMultiPGN("file.pgn")

src/game.nim

@@ -1,26 +1,93 @@
-import ./chess
+import parseutils
 
-proc runGame*(): void =
+import chess
-  ## Initializes and runs a game of chess.
+import engine/engine
-  var game = initGame()
+
+proc runGameHotseat*(): void =
+  ## Initializes and runs a game of chess as hotseat.
+  var chess = initChess()
   var draw: string
-  game.echoBoard(game.toMove)
+  chess.echoBoard(chess.toMove)
-  while not game.isCheckmate(game.toMove) and not game.isStalemate(game.toMove):
+  while not chess.isCheckmate(chess.toMove) and not chess.isStalemate(chess.toMove):
     echo "Make a move"
-    echo game.toMove
+    echo chess.toMove
     var move = readLine(stdin)
-    while not game.checkedMove(notationToMove(move, game.toMove)):
+    while not chess.checkedMove(notationToMove(move, chess.toMove)):
       move = readLine(stdin)
-    game.echoBoard(game.toMove)
+    chess.echoBoard(chess.toMove)
-    if (game.isDrawClaimable):
+    if chess.isDrawClaimable():
       echo "Do you want to claim a draw? (y/N)"
       draw = readLine(stdin)
-      if (draw == "y"):
+      if draw == "y":
         echo "Draw claimed"
         break
-  if game.isCheckmate(game.toMove):
+  if chess.isCheckmate(chess.toMove):
-    echo $game.toMove & " was checkmated"
+    echo $chess.toMove & " was checkmated"
-  if game.isStalemate(game.toMove):
+  if chess.isStalemate(chess.toMove):
     echo "Stalemate"
 
-runGame()
+proc runGameSolo*(color: Color, difficulty: int): void =
+  ## Initializes and runs a solo game of chess.
+  ## The player plays as `color`.
+  echo("run game")
+  var chess = initChess()
+  var draw: string
+  while not chess.isCheckmate(chess.toMove) and not chess.isStalemate(chess.toMove):
+    if chess.toMove == color:
+      chess.echoBoard(color)
+      echo "Make a move"
+      var hMove = readLine(stdin)
+      while not chess.checkedMove(notationToMove(hMove, chess.toMove)):
+        hMove = readLine(stdin)
+      chess.echoBoard(color)
+      if chess.isDrawClaimable():
+        echo "Do you want to claim a draw? (y/N)"
+        draw = readLine(stdin)
+        if draw == "y":
+          echo "Draw claimed"
+          break
+    else:
+      var cMove = bestMove(chess, difficulty)
+      chess.checkedMove(cMove)
+  if chess.isCheckmate(chess.toMove):
+    echo $chess.toMove & " was checkmated"
+  if chess.isStalemate(chess.toMove):
+    echo "Stalemate"
+
+proc menu(): void =
+  ## Presents choices on what to play.
+  echo("\nWelcome to YchESs!\n\n\n")
+  var input: string
+  var playerCount: int
+  while true:
+    echo("How many players? (1/2)")
+    input = readLine(stdin)
+    discard parseInt(input, playerCount, 0)
+    if playerCount == 1 or playerCount == 2:
+      break
+  if playerCount == 1:
+    var color: string
+    var difficulty: int
+    while true:
+      echo("Choose the difficulty for the engine (1-10)")
+      input = readLine(stdin)
+      discard parseInt(input, difficulty, 0)
+      if difficulty >= 1 and difficulty <= 10:
+        break
+    while true:
+      echo("Do you want to play Black or White? (B/W)")
+      color = readLine(stdin)
+      if color == "B":
+        echo("\n\n\n")
+        runGameSolo(Color.Black, difficulty)
+        break
+      elif color == "W":
+        echo("\n\n\n")
+        runGameSolo(Color.White, difficulty)
+        break
+  else:
+    echo("\n\n\n")
+    runGameHotseat()
+
+when isMainModule:
+  menu()

src/project.nim

@@ -0,0 +1,15 @@
+import os
+
+proc getProjRootDir*(): string =
+  ## Returns the root directory for the ychess project.
+  var maxDepth = 4
+  var path = os.getCurrentDir()
+  var projectDir: string
+  while maxDepth > 0:
+    if dirExists(joinPath(path, "src")):
+      projectDir = path
+      break
+    else:
+      path = parentDir(path)
+    maxDepth -= 1
+  return projectDir

tests/engineTest.nim

@@ -0,0 +1,48 @@
+import einheit
+
+include chess
+include engine/engine
+
+testSuite ChessTest of TestSuite:
+
+  var
+    chess: Chess
+
+  method setup() =
+    self.chess = initChess()
+
+  method testPieceEvalStalemate() =
+    self.chess = initChess("8/8/2k5/8/8/5K2/8/8 b - - 0 1")
+    var pieceEvaluation = self.chess.evaluate()
+    self.check(pieceEvaluation == 0)
+
+  method testBestMoveProm() =
+    self.chess = initChess("8/2k1P3/8/8/8/5K2/8/8 w - - 0 1")
+    var testBestMove = self.chess.bestMove(2)
+    self.check(testBestMove.start != 0)
+    self.check(indToField(testBestMove.start) == "e7")
+    self.check(indToField(testBestMove.dest) == "e8")
+
+  method testBestMoveStopProm() =
+    self.chess = initChess("8/2k1P3/8/8/8/5K2/8/8 b - - 0 1")
+    var testBestMove = self.chess.bestMove(2)
+    self.check(testBestMove.start != 0)
+    self.check(indToField(testBestMove.start) == "c7")
+    self.check(indToField(testBestMove.dest) == "d7")
+
+  method testBestMoveTacticBlack() =
+    self.chess = initChess("8/2k3r1/8/6p1/5P2/8/4K1R1/8 b - - 0 1")
+    var testBestMove = self.chess.bestMove(2)
+    self.check(testBestMove.start != 0)
+    self.check(indToField(testBestMove.start) != "g5" or indToField(
+        testBestMove.dest) != "f4")
+
+  method testBestMoveTacticWhite() =
+    self.chess = initChess("8/2k3r1/8/5p2/6P1/8/4K1R1/8 w - - 0 1")
+    var testBestMove = self.chess.bestMove(2)
+    self.check(testBestMove.start != 0)
+    self.check(indToField(testBestMove.start) != "g4" or indToField(
+        testBestMove.dest) != "f5")
+
+when isMainModule:
+  einheit.runTests()