#   Cell.py -- Cell and Total classes for k1.py, a kakuro solver.
#   Copyright (C) 2010 Collin Park
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   See <http://www.gnu.org/licenses/> for full license text. """

# A Cell has:
#   designator: row 1..99, column A..Z 
#   Type: gray, sums, 1-9, 0 (for unknown)
#   possible values (list)
#   2 possible totals:
#      across, down.  Each one has:
#                       backpointer to cell
#                       what kind am i (down or across)
#                       required sum
#                       list of cells
#                       "live" list of possible combos
#   array of 2 possible "totals":
#      across, down.  Each one has:
#                       backpointer to the 'total' structure
GRAY = 'gray'
SUMS = 'sums'
ACROSS = 'across'
DOWN = 'down'
col_name = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"     # no more than 26
class Cell:
    def __init__(self, myrow, mycol, mytype=GRAY, dtotal=0, atotal=0):
        self.row = myrow
        self.col = mycol
        self.type = mytype
        self.above = None
        self.below = None
        self.left = None
        self.right = None
        self.dtotal = None
        self.atotal = None
        if dtotal != 0:
            self.dtotal = Total(self, DOWN, dtotal)
        if atotal != 0:
            self.atotal = Total(self, ACROSS, atotal)
        self.possibles = None
        if mytype not in (GRAY, SUMS):
            self.possibles = range(1,10)                # 1..9
    def name(self):
        return `self.row` + col_name[self.col]

class Total:
    def __init__(self, mycell, mykind, mysum):
        self.cell = mycell
        self.kind = mykind
        self.sum = mysum
        # Fill these two in later.  Names here so I don't forget.
        self.cells = list()
        self.combos = list()      
        self.permutes = None
    def has_undecided(self):
        for acell in self.cells:
            if acell.type == 0:
                return True
        return False