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

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

search and print all solutions of a sudoku puzzle described by a string on the command line

"""

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>'.format(sys.argv[0]))
    print('where <grid> is a 81 characters string describing a valid sudoku grid')
    print('\nExample: with the grid')
    print(GRID)
    print('$ {:s} 906028003040500001080900040600000070008206900030000005050003060100002080200870500'.format(sys.argv[0]))
    exit(1)
    
if __name__ == '__main__':
    import sys
    import sudoku_grid, sudoku_solver

    if len(sys.argv) != 2:
        usage()
    else:
        strgrid = sys.argv[1]
        try:
            grid = sudoku_grid.SudokuGrid(strgrid)
        except sudoku_grid.SudokuGridError:
            usage()
        print('Sudoku to solve')
        grid.pretty_print()
        sols = sudoku_solver.solve(grid)
        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('--')
        
    exit(0)