from pseudoku.grid import Grid
from pseudoku.grid.constraints import Diagonal

from pseudoku.tests import SudokuTestCase

class DiagonalGridTestCase(SudokuTestCase):
    """Tests that grids with extra Diagonal constraints are solved."""

    def test_main_diagonals(self):
        """Tests an easy puzzle with constraints along both main diagonals."""

        grid = Grid.from_string("""
            3...2...7 ...3.1...  ..6...4..
            89.....54 4...5...8 61.....32
            ..8...2..  ...5.9...  1...6...9
        """)
        grid.add_constraint(Diagonal(grid, direction='down', offset=0))
        grid.add_constraint(Diagonal(grid, direction='up', offset=0))
        self.assertSolvable(grid, "Main diagonals (Color Sudoku, page 8)")