/*----- constants -----*/
const STONES_DATA = {
  '-1': 'white',
  '0': 'none',
  '1': 'black',
  'k': 'ko'
}


// index corresponds to difference in player rank
const KOMI_REC = {
  '9': [
    5.5, 2.5, -0.5, -3.5, -6.5, -9.5, 12.5, 15.5, 18.5, 21.5
  ],
  '13': [
    5.5, 0.5, -5.5, 0.5, -5.5, 0.5, -5.5, 0.5, -5.5, 0.5
  ],
  '19': [
    7.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5
  ]
}

const HANDI_REC = {
  '9': [
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  ],
  '13': [
    0, 0, 0, 2, 2, 3, 3, 4, 4, 5
  ],
  '19': [
    0, 0, 2, 3, 4, 5, 6, 7, 8, 9
  ]
}

// index represents handicap placement for different board-sizes, eg handiPlace['9][1] = { (3, 3), (7, 7) }
// last array in each property also used for hoshi rendering 
const HANDI_PLACE = {
  '9' : [
    0, 0,
    [[ 7, 3 ], [ 3, 7 ] ], 
    [ [ 7, 7 ], [ 7, 3 ], [ 3, 7 ] ], 
    [ [ 3, 3 ], [ 7, 7 ], [ 3, 7 ], [ 7, 3 ] ] 
  ],
  '13' : [
    0, 0,
    [ [ 4, 10 ], [ 10, 4 ] ],
    [ [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 7, 7 ], [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 7, 4 ], [ 4, 7 ], [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 7, 7 ], [ 7, 4 ], [ 4, 7 ], [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 10, 7 ], [ 7, 4 ], [ 7, 10 ], [ 4, 7 ], [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
    [ [ 7, 7 ], [ 10, 7 ], [ 7, 4 ], [ 7, 10 ], [ 4, 7 ], [ 4, 4 ], [ 10, 10 ], [ 4, 10 ], [ 10, 4] ],
  ],
  '19' : [
    0, 0,
    [ [ 4, 16 ], [ 16, 4 ] ],
    [ [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 10, 10 ], [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 10, 4 ], [ 4, 10 ], [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 10, 10 ], [ 10, 4 ], [ 4, 10 ], [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 16, 10 ], [ 10, 4 ], [ 10, 16 ], [ 4, 10 ], [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
    [ [ 10, 10 ], [ 16, 10 ], [ 10, 4 ], [ 10, 16 ], [ 4, 10 ], [ 4, 4 ], [ 16, 16 ], [ 4, 16 ], [ 16, 4] ],
  ]
};

const pipeMap = (...funcs) => obj => {
  const arr = Object.entries(obj).reduce((acc, [key, value]) => {
    funcs.forEach(func => value = func(value));
    return [...acc, [key, value]];
  },[]);
  return arr.reduce((acc, [key, value]) => {
    return { ...acc, [key]: value }
  }, {});
}

const checkLegal = ({ point, Game }) => {
  return 'l';
}

const getBoardState = (Game) => {
  const getLegal = point => checkLegal({ point, Game });
  return pipeMap(getLegal)(Game.boardState);
}

const initBoard = boardSize => {
  const boardState = {};
  for (let i = 0; i < Math.pow(boardSize, 2); i++) {
    const point = Point({
      x: Math.floor(i / boardSize) + 1, 
      y: i % boardSize + 1, 
      boardSize 
    });
    boardState[`${point.pos.x}-${point.pos.y}`] = point;
  }
  return boardState;
}

// returns Game object
const Game = ({gameData, gameRecord} = {}) => ({
  winner:       gameData ? gameData.winner    : null,
  turn:         gameData ? gameData.turn      : 1, // turn logic depends on handicap stones
  pass:         gameData ? gameData.pass      : 0, // -1 represents state in which resignation has been submitted, not confirmed
  komi:         gameData ? gameData.komi      : 6.5, // komi depends on handicap stones + player rank
  handicap:     gameData ? gameData.handicap  : 0,
  boardSize:    gameData ? gameData.boardSize : 19,
  groups:       {},
  boardState:   {},
  gameRecord:   gameRecord || [],
  playerState:  gameData ? gameData.playerState : {
    bCaptures: 0,
    wCaptures: 0,
    bScore: 0,
    wScore: 0
  },

  initGame: function() {
    this.winner =     null;
    this.pass =       0;
    this.turn =       this.handicap ? -1 : 1;
    this.boardState = initBoard(this.boardSize)
    return getBoardState(this);
  }
});

const Point = ({x, y, boardSize = 19}) => ({
  pos:          {x, y},
  stone:        0, // can be 1, -1, 0, or 'k' for ko
  legal:        0,
  territory:    0,
  capturing:    [],
  groupMembers: [ this ],
  neighbors: {
    top: x > 1          ? `${ x - 1 }-${ y }` : null,
    btm: x < boardSize  ? `${ x + 1 }-${ y }` : null,
    rgt: y < boardSize  ? `${ x }-${ y + 1 }` : null,
    lft: y > 1          ? `${ x }-${ y - 1 }` : null
  }
});

module.exports = {
  Game,
  Point
}