from __future__ import annotations

from app.journey import _filter_dominated_journeys
from app.journey_search import _rank_journeys, _select_diverse_journeys


def test_progressive_selection_keeps_fast_and_low_walk_transit_options():
    fast_with_walk = _journey(
        "fast",
        arrival=30_000,
        transfers=0,
        legs=[
            _leg("tram", "22", "A", "B"),
            _leg("walk", "walk", "B", "Z", distance_m=1200),
        ],
    )
    slower_low_walk = _journey(
        "low-walk",
        arrival=31_200,
        transfers=1,
        legs=[
            _leg("tram", "22", "A", "Hbf"),
            _leg("bus", "34", "Hbf", "Y"),
            _leg("walk", "walk", "Y", "Z", distance_m=120),
        ],
    )
    walk_only = _journey(
        "walk-only",
        arrival=30_900,
        transfers=0,
        legs=[_leg("walk", "walk", "A", "Z", distance_m=1800)],
    )

    ranked = _rank_journeys([slower_low_walk, walk_only, fast_with_walk], "recommended")
    selected = _select_diverse_journeys(ranked, limit=3)

    assert len(selected) <= 3
    assert {journey["id"] for journey in selected} == {"fast", "low-walk", "walk-only"}


def test_progressive_selection_collapses_same_journey_from_duplicate_gtfs_feeds():
    rnv = _journey(
        "rnv",
        arrival=29_820,
        transfers=0,
        legs=[
            _leg("walk", "walk", "Jakob-Neu-Straße 2", "Eppelheim Rathaus", dataset_id=10, source_name=None),
            _leg("tram", "RNV 22", "Eppelheim Rathaus", "Heidelberg Hbf", dataset_id=10, source_name="DE Verkehrsverbund Rhein-Neckar GTFS"),
        ],
    )
    delfi = _journey(
        "delfi",
        arrival=29_820,
        transfers=0,
        legs=[
            _leg("walk", "walk", "Jakob-Neu-Straße 2", "Eppelheim Rathaus", dataset_id=4, source_name=None),
            _leg("tram", "RNV 22", "Eppelheim Rathaus", "Heidelberg Hbf", dataset_id=4, source_name="DELFI / GTFS.de Germany", stop_count=8),
        ],
    )

    ranked = _rank_journeys([rnv, delfi], "recommended")
    selected = _select_diverse_journeys(ranked, limit=3)

    assert [journey["id"] for journey in selected] == ["delfi"]


def test_dominance_removes_only_slower_more_transfer_same_endpoint_options():
    direct = _journey(
        "direct",
        arrival=30_000,
        transfers=0,
        legs=[
            _leg("tram", "22", "A", "platform-a", canonical_to=500),
            _leg("walk", "walk", "platform-a", "Z", distance_m=800),
        ],
    )
    faster_transfer = _journey(
        "faster-transfer",
        arrival=29_500,
        transfers=1,
        legs=[
            _leg("bus", "34", "A", "X"),
            _leg("tram", "5", "X", "platform-b", canonical_to=500),
            _leg("walk", "walk", "platform-b", "Z", distance_m=800),
        ],
    )
    slower_transfer = _journey(
        "slower-transfer",
        arrival=31_000,
        transfers=1,
        legs=[
            _leg("bus", "713", "A", "Y"),
            _leg("tram", "22", "Y", "platform-c", canonical_to=500),
            _leg("walk", "walk", "platform-c", "Z", distance_m=800),
        ],
    )

    filtered = _filter_dominated_journeys([slower_transfer, faster_transfer, direct])

    assert {journey["id"] for journey in filtered} == {"direct", "faster-transfer"}


def _journey(journey_id: str, *, arrival: int, transfers: int, legs: list[dict]) -> dict:
    departure = 28_800
    return {
        "id": journey_id,
        "departure_seconds": departure,
        "arrival_seconds": arrival,
        "duration_seconds": arrival - departure,
        "duration_minutes": (arrival - departure + 59) // 60,
        "transfers": transfers,
        "legs": legs,
    }


def _leg(
    mode: str,
    route: str,
    from_stop: str,
    to_stop: str,
    *,
    distance_m: float = 0,
    canonical_to: int | None = None,
    dataset_id: int = 1,
    source_name: str | None = "Test GTFS",
    stop_count: int = 2,
) -> dict:
    to_payload = {"stop_id": to_stop}
    stops = [{"stop_id": from_stop}, {"stop_id": to_stop}]
    if canonical_to is not None:
        stops[-1]["canonical_stop"] = {"id": canonical_to}
    return {
        "dataset_id": dataset_id,
        "source_name": source_name,
        "mode": mode,
        "route_id": route,
        "route_ref": route,
        "trip_id": f"{route}-trip" if mode != "walk" else None,
        "from": {"stop_id": from_stop},
        "to": to_payload,
        "departure_time": "08:00:00",
        "arrival_time": "08:10:00",
        "distance_m": distance_m,
        "stop_count": stop_count if mode != "walk" else None,
        "intermediate_stop_count": max(0, stop_count - 2) if mode != "walk" else None,
        "stops": stops,
    }