#!/usr/bin/python3
# -*- coding: utf-8 -*-

"""
:mod: module
:author: `Éric W`
:date: 2016, october

"""

GRID='''
   +-------+-------+-------+
   | 9 . 6 | . 2 8 | . . 3 |
   | . 4 . | 5 . . | . . 1 |
   | . 8 . | 9 . . | . 4 . |
   +-------+-------+-------+
   | 6 . . | . . . | . 7 . |
   | . . 8 | 2 . 6 | 9 . . |
   | . 3 . | . . . | . . 5 |
   +-------+-------+-------+
   | . 5 . | . . 3 | . 6 . |
   | 1 . . | . . 2 | . 8 . |
   | 2 . . | 8 7 . | 5 . . |
   +-------+-------+-------+
'''

def usage():
    print('Usage: {:s} <grid> <dot_filename>'.format(sys.argv[0]))
    print('where\n\t<grid> is a 81 characters string describing a valid sudoku grid')
    print('\t<dot_filename> is the name of the file containing the resolution\'s tree description')
    print('\nExample: with the grid')
    print(GRID)
    print('$ {:s} 906028003040500001080900040600000070008206900030000005050003060100002080200870500 tree_resolution'.format(sys.argv[0]))
    exit(1)
    
if __name__ == '__main__':
    import sys, os
    import sudoku_grid, sudoku_solver

    if len(sys.argv) != 3:
        usage()
    else:
        strgrid = sys.argv[1]
        try:
            grid = sudoku_grid.SudokuGrid(strgrid)
        except sudoku_grid.SudokuGridError:
            usage()
        filename = sys.argv[2]
        print('Sudoku to solve')
        grid.pretty_print()
        with open(filename + '.dot', 'w') as output:
            node = 'START'
            output.write(
'''/*
        Resolution tree for sudoku number
*/
digraph T {{
\tbgcolor="#FFFF00";
\tnode[style=filled];
\t{:s}[shape=hexagon, fillcolor="#FF0000"];
'''.format(node))
            sols = sudoku_solver.solve(grid, output, node)
            output.write('}\n')
        nb_sols = len(sols)
        print('Number of solution(s): {:d}'.format(nb_sols))
        print('--')
        for i in range(nb_sols):
            print('Solution {:d}'.format(i + 1))
            sols[i].pretty_print()
            print('--')

    os.system('dot -Tpng -o {0:s}.png {0:s}.dot'.format(filename))
    exit(0)