tic-tac-toe

// 1. Think about the Data
// -Get out all of the data that's relavent in the right shape
// -Funcitons that transform that data from one state to the next state
//
// Invarient: True for every game
// -2 Players
// -2 symbols for each player
// -Some Mapping between the player and the symbol
// -3x3 grid with a total of 9 squares
// -moves / history of moves

// New Game:
var initGameState = {
  player1: null,
  player2: null,
  sideLength: 3,
  moves: []
}

const WINNING_COMBINATIONS = [
  [[0,0], [0,1], [0,2]],
  [[1,0], [1,1], [1,2]],
  [[2,0], [2,1], [2,2]],
  [[0,0], [1,0], [2,0]],
  [[0,1], [1,1], [2,1]],
  [[0,2], [1,2], [2,2]],
  [[0,0], [1,1], [2,2]],
  [[0,2], [1,1], [2,0]],
]

var getPlayerSymbols = function(/*Record*/ gameState) { /* Record */
  var sym = null;

  do {
    sym = prompt("Hello player one enter 'x' or 'o'?");
  } while (!validateSymbolSelection(sym));

  gameState.player1 = parseSymbolSelection(sym);
  gameState.player2 = oppositeSym(sym);
  return gameState;
}

var oppositeSym = function(/*string*/sym) { /* string */
  return (sym === 'x' ? 'o' : "x")
}

var validateSymbolSelection = function(/*String*/ sym) { /* string */
  return (sym === 'x' || sym === 'o');
}

var parseSymbolSelection = function(/*String*/ sym) { /*string*/
  return sym.toLowerCase();
}

var getPlayerMove = function(/*Record, string*/ gameState) { /* Record */
  var move = null;
  var playerSym = winner(gameState);

  do {
    renderBoard(gameState.moves);
    move = prompt("It's your turn to move, enter [x,y] coordiate of your move")
    move = parseMoveString(move);
  } while (!validateMove(move, gameState));

  var moveAndSym = [move, playerSym];
  gameState.moves.push(moveAndSym);
  return gameState;
}

var renderBoard = function(/*List*/moves) { /* print row */
  var board = createBoard(moves);
  board.forEach(function(row) {
    console.log(row);
  })
}

var createBoard = function(/*list*/moves) {/* list */
  var board = [["-", "-", "-"], ["-", "-", "-"], ["-", "-", "-"]];
  return moves.reduce(function(boardWithMoves, move) {
    var x = move[0][0];
    var y = move[0][1];
    boardWithMoves[x][y] = move[1];
    return boardWithMoves;
  }, board)
}

var validateMove = function(/*Pair<int, int>, Record */ move, gameState) {/* boolean */
  if(!arrayIncludesArray(gameState.moves, move)) {
    return (move[0] >= 0 && move[0] < 3) && (move[1] >= 0 && move[1] < 3)
  } else {
    return false;
  }
}

var parseMoveString = function(/*String*/ move) { /* Pair<int, int> */
  return move.split(",").map(function(el) { return parseInt(el) })
}

var boardWinning = function(/*Record*/gameState) {/* Record */

  if(wonGame(gameState)) {
    return winner(gameState);
  } else if (gameState.moves.length === 8) {
    return "it's a tie";
  } else {
    var gameState = getPlayerMove(gameState);
    return boardWinning(gameState);
  }
}

var wonGame = function(/*Record*/ gameState) { /* boolean true or false */
  return WINNING_COMBINATIONS.reduce(function(won, winningCombo, player) {
    return arrayContainsWinningMove(gameState, winningCombo) ? true : won;
  }, false)
}

var arrayContainsWinningMove = function(/*Record, List<Triple<Pair<int, int>>>*/ gameState, innerArray) {

  return innerArray.reduce(function(match, pair) {
    return !winningArrIncludesSyms(gameState, pair) ? false : match;
  }, true)
}

var winningArrIncludesSyms = function(/*Record, Pair<int, int>,*/gameState, moveArr) { /* boolean true or false */
  var player = winner(gameState);

  return gameState.moves.reduce(function(checkedArray, arr) {
    return arr[0].join("") === moveArr.join("") && player === arr[1] ? true : checkedArray;
  }, false)
}

var arrayIncludesArray = function(/*Array, Pair<int, int>*/givenArray, moveArr) { /* boolean true or false */
  return givenArray.reduce(function(checkedArray, arr) {
    return arr[0].join("") === moveArr.join("") ? true : checkedArray;
  }, false)
}

var winner = function(/*Record */ gameState) { /* string */
  // determines whether player1 or player2 made the winning move
  var numMoves = gameState.moves.length;
  return numMoves === 0 || numMoves % 2 === 0 ? gameState.player1 : gameState.player2;
}

console.log(boardWinning(getPlayerSymbols(initGameState)));