#!/usr/bin/env python3
# todo list:
# - fix all the todos in the document
# - move 'position' data to its own class with dynamic conversion between

class Board:
    unplayed = 0
    cross = 1
    nought = 2
    mappings = {
            'a': 0,
            'b': 1,
            'c': 2,
            'd': 3,
            'e': 4,
            'f': 5,
            'g': 6,
            'h': 7,
            'i': 8,
    }
    reverse = {i[1]:i[0] for i in mappings.items()}
    def __init__(self):
        self.board = [[[
            [Board.unplayed for i in range(3)] for j in range(3)
        ] for k in range(3) ] for l in range(3) ]
        self.movestring = []
        self.turn = Board.cross
    def push(self, movestring):
        pos = self.translateGlobal(movestring)
        self.movestring.append(movestring)
        self.board[pos[0]][pos[1]][pos[2]][pos[3]] = self.turn

        if self.turn == Board.cross:
            self.turn = Board.nought
        else:
            self.turn = Board.cross
    def subboardWin(self, x, y):
        b = self.board
        for i in range(3):
            if b[x][y][i][0] == b[x][y][i][1] == b[x][y][i][2]:
                if b[x][y][i][0] != Board.unplayed:
                    return b[x][y][i][0]
            if b[x][y][0][i] == b[x][y][1][i] == b[x][y][2][i]:
                if b[x][y][0][i] != Board.unplayed:
                    return b[x][y][0][i]
        if b[x][y][0][0] == b[x][y][1][1] == b[x][y][2][2]:
            if b[x][y][0][0] != Board.unplayed:
                return b[x][y][0][0]
        if b[x][y][2][0] == b[x][y][1][1] == b[x][y][0][2]:
            if b[x][y][2][0] != Board.unplayed:
                return b[x][y][2][0]
        return Board.unplayed
    def allEmpty(self):
        buf = []
        for i in range(3):
            for j in range(3):
                for k in range(3):
                    for l in range(3):
                        if self.board[i][j][k][l] == Board.unplayed:
                            buf.append(self.translateLocal((i, j, k, l)))
    def possibleMoves(self):
        # get last move
        try:
            lastpos = self.movestring[-1]
        except IndexError:
            # if no moves have been made, return the whole board
            ret = []
            for i in range(9):
                for j in range(9):
                    buf = []
                    buf.append(Board.reverse[i])
                    buf.append(str(j))
                    ret.append(''.join(buf))

            return ret

        # get global tuple
        lastpos = self.translateGlobal(lastpos)
        # check for a subboard win condition in the indicated
        # position; if so, just return self.allEmpty()

        # WARNING: this will select positions in already won boards that are empty
        # needs to be fixed
        if self.subboardWin(lastpos[0], lastpos[1]):
            return self.allEmpty()

        # get all squares in metasquare
        # this doesn't work because it's getting the *current* square
        # and not the square the move is referring to
        # this needs to be fixed
        square = self.returnInSquare(self.movestring[-1])
        buf = []
        for i in square:
            # if empty, we can move
            if self.isEmpty(i):
                buf.append(i)

        return buf
    def translateGlobal(self, movestring):
        globcoords = (
                Board.mappings[movestring[0]],
                int(movestring[1]) - 1,
        )

        subboard = (
                int(globcoords[0] / 3),
                int(globcoords[1] / 3),
        )

        localpos = (
                globcoords[0] % 3,
                globcoords[1] % 3,
        )

        return (subboard[0], subboard[1], localpos[0], localpos[1])

    def translateLocal(self, globaltuple):
        globcoords = (
                globaltuple[0] * 3 + globaltuple[2],
                globaltuple[1] * 3 + globaltuple[3] + 1,
        )

        movestring = []
        movestring.append(Board.reverse[globcoords[0]])
        movestring.append(str(globcoords[1]))

        return ''.join(movestring)

    def returnInSquare(self, movestring, convert=True):
        orig = self.translateGlobal(movestring)
        buf = []
        for i in range(3):
            for j in range(3):
                buf.append((orig[0], orig[1], i, j))

        if convert:
            rbuf = []
            for i in buf:
                rbuf.append(Board.translateLocal(self, i))

            return rbuf

        return buf
    def isEmpty(self, movestring):
        orig = self.translateGlobal(movestring)
        item = self.board[orig[0]][orig[1]][orig[2]][orig[3]]
        if item == Board.unplayed:
            return True
        return False
    def isFull(self, movestring):
        return not self.isEmpty(movestring)
    def getInnerBoard(self, x, y):
        pass