from puga import route

# Small synthetic graph: A-B-C in a line, A-D direct (shorter), D-C (closes a loop so Dijkstra has a choice)
GRAPH = {
    "A": {"name": "A", "natural_id": "A", "pos": None, "neighbors": {"B": 10.0, "D": 3.0}},
    "B": {"name": "B", "natural_id": "B", "pos": None, "neighbors": {"A": 10.0, "C": 10.0}},
    "C": {"name": "C", "natural_id": "C", "pos": None, "neighbors": {"B": 10.0, "D": 10.0}},
    "D": {"name": "D", "natural_id": "D", "pos": None, "neighbors": {"A": 3.0, "C": 10.0}},
}


def test_shortest_path_picks_lower_total_distance_not_fewer_jumps():
    r = route.shortest_path("A", "C", graph=GRAPH)
    assert r["path"] == ["A", "D", "C"]      # 3+10=13, beats A-B-C's 10+10=20 despite same jump count
    assert r["jumps"] == 2
    assert r["distance_ly"] == 13.0


def test_same_system_is_zero_jumps():
    r = route.shortest_path("A", "A", graph=GRAPH)
    assert r["jumps"] == 0
    assert r["distance_ly"] == 0.0


def test_no_route_returns_none():
    graph = dict(GRAPH)
    graph["E"] = {"name": "E", "natural_id": "E", "pos": None, "neighbors": {}}
    assert route.shortest_path("A", "E", graph=graph) is None