import unittest

from pygraph.graphdemo import Graph


class GraphTestCase(unittest.TestCase):
    def test_construct_a_graph(self):
        g = Graph()
        g.add_edge(1, 2)
        g.add_edge(1, 3)
        g.add_edge(2, 3)
        g.add_edge(2, 4)
        txt = str(g)
        expected = '''1 → [2, 3]
2 → [1, 3, 4]
3 → [1, 2]
4 → [2]'''
        self.assertEqual(expected, txt)
        vertices = [1, 2, 3, 4]
        # def action(v): self.assertTrue(v in vertices)
        g.for_each_vertices(lambda v : self.assertTrue(v in vertices))

    def test_iterate_all_edges(self):
        g = Graph()
        g.add_edge(1, 2)
        g.add_edge(1, 3)
        g.add_edge(2, 3)
        g.add_edge(2, 4)
        edges = [
            "1-2", "1-3", "2-3", "2-4"
        ]
        def action(a, b):
            (s,e) = (a,b) if a < b else (b,a)
            edge = f"{s}-{e}"
            self.assertTrue(edge in edges)
        g.for_each_edges(action)


if __name__ == '__main__':
    unittest.main()