"""Match-statistics tests: Postgres persistence and the stats endpoints."""
from __future__ import annotations

import unittest
import uuid
from datetime import datetime, timezone

from httpx import ASGITransport, AsyncClient

from tavolo.platform.elo import INITIAL_RATING
from tavolo.platform.models import Match, MatchPlayer, PlayerRating
from tavolo.platform.stats import save_match_result
from helpers import DummyEngine, async_test, make_platform, oidc_user, use_db


def _finished_session(target: int = 2):
    """A started dummy session one play short of completion."""
    from tavolo.platform import GameSession, Seat

    engine = DummyEngine()
    session = GameSession(
        id="stats-game",
        game_type=engine.id,
        join_code="STATS1",
        creator_sub="alice",
        players=[Seat(user_sub="alice", display_name="alice", team="A")],
    )
    engine.create(session, {"target": target})
    engine.join(session, "bob", "bob")
    engine.handle_action(session, "alice", "play", {})
    return engine, session


class SaveMatchResultTest(unittest.TestCase):
    @async_test
    async def test_finished_match_is_persisted_once(self) -> None:
        _, _, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        engine, session = _finished_session()
        engine.handle_action(session, "alice", "play", {})
        self.assertTrue(engine.is_finished(session))

        with ctx:
            await save_match_result(session, engine)
            await save_match_result(session, engine)  # idempotent
            self.assertEqual(1, await Match.all().count())
            self.assertEqual(2, await MatchPlayer.all().count())

            match = await Match.all().first()
            assert match is not None
            # The game type travels from the session onto the row; the
            # engine's summary is stored verbatim as the result.
            self.assertEqual("dummy", match.game_type)
            self.assertEqual("alice", match.result["winner"])
            self.assertEqual(2, match.result["plays"])
            winners = await MatchPlayer.filter(won=True)
            self.assertEqual({"alice"}, {p.user_sub for p in winners})
            scores = {p.user_sub: p.score for p in await MatchPlayer.all()}
            self.assertEqual({"alice": 2.0, "bob": 0.0}, scores)

    @async_test
    async def test_finished_match_updates_elo_ratings(self) -> None:
        _, _, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        engine, session = _finished_session()
        engine.handle_action(session, "alice", "play", {})

        with ctx:
            await save_match_result(session, engine)

            ratings = {
                row.user_sub: row for row in await PlayerRating.all()
            }
            self.assertEqual(2, len(ratings))
            # Two players at 1500: winner gains K/2, loser loses it.
            self.assertEqual(INITIAL_RATING + 16, ratings["alice"].rating)
            self.assertEqual(1, ratings["alice"].matches_played)
            self.assertEqual(INITIAL_RATING - 16, ratings["bob"].rating)
            self.assertEqual(1, ratings["bob"].matches_played)

            # The per-match delta is recorded on each participation row.
            deltas = {
                p.user_sub: p.elo_delta for p in await MatchPlayer.all()
            }
            self.assertEqual({"alice": 16, "bob": -16}, deltas)

    @async_test
    async def test_elo_ratings_accumulate_across_matches(self) -> None:
        _, _, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        engine, session = _finished_session()
        engine.handle_action(session, "alice", "play", {})

        from tavolo.platform import GameSession, Seat

        engine2, session2 = DummyEngine(), GameSession(
            id="stats-game-2",
            game_type="dummy",
            join_code="STATS2",
            creator_sub="alice",
            players=[Seat(user_sub="alice", display_name="alice", team="A")],
        )
        engine2.create(session2, {"target": 2})
        engine2.join(session2, "bob", "bob")
        # Bob wins the second match.
        engine2.handle_action(session2, "bob", "play", {})
        engine2.handle_action(session2, "bob", "play", {})

        with ctx:
            await save_match_result(session, engine)
            await save_match_result(session2, engine2)

            ratings = {
                row.user_sub: row.rating for row in await PlayerRating.all()
            }
            # Match 1: even teams, alice wins (+16/-16). Match 2: alice
            # is now the favourite (1516 vs 1484), so losing costs 17.
            self.assertEqual(INITIAL_RATING - 1, ratings["alice"])
            self.assertEqual(INITIAL_RATING + 1, ratings["bob"])
            bob = await PlayerRating.get(user_sub="bob")
            self.assertEqual(2, bob.matches_played)

    @async_test
    async def test_unfinished_match_is_not_persisted(self) -> None:
        _, _, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        engine, session = _finished_session()
        with ctx:
            await save_match_result(session, engine)
            self.assertEqual(0, await Match.all().count())


async def _seed_two_matches(
    tortoise_mixin, game_types: tuple = ("dummy", "dummy")
) -> None:
    ctx = await use_db(tortoise_mixin)
    with ctx:
        for index, (winner, finished) in enumerate(
            [
                ("alice", datetime(2026, 1, 1, 10, tzinfo=timezone.utc)),
                ("bob", datetime(2026, 1, 2, 10, tzinfo=timezone.utc)),
            ]
        ):
            match = await Match.create(
                id=uuid.uuid4(),
                game_type=game_types[index],
                started_at=datetime(2025, 12, 31, tzinfo=timezone.utc),
                finished_at=finished,
                result={"winner": winner, "plays": 3 + index},
            )
            for seat, sub in enumerate(("alice", "bob")):
                await MatchPlayer.create(
                    id=uuid.uuid4(),
                    match=match,
                    user_sub=sub,
                    display_name=sub,
                    seat=seat,
                    team="A" if seat == 0 else "B",
                    won=(sub == winner),
                    score=2.0 + index if sub == winner else 1.0,
                )


class StatsRouteTest(unittest.TestCase):
    @async_test
    async def test_my_matches_newest_first(self) -> None:
        app, platform, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin)
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            with oidc_user(platform.oidc, "alice"):
                response = await client.get("/api/me/matches")
            self.assertEqual(200, response.status_code)
            results = response.json()["results"]
            self.assertEqual(2, len(results))
            self.assertEqual("bob", results[0]["result"]["winner"])  # newest first
            self.assertFalse(results[0]["you_won"])
            self.assertTrue(results[1]["you_won"])
            self.assertEqual(2, len(results[0]["players"]))
            self.assertIn("next_cursor", response.json())

    @async_test
    async def test_my_matches_pagination(self) -> None:
        app, platform, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin)
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            with oidc_user(platform.oidc, "alice"):
                first = await client.get("/api/me/matches?limit=1")
                cursor = first.json()["next_cursor"]
                self.assertIsNotNone(cursor)
                second = await client.get(f"/api/me/matches?limit=1&cursor={cursor}")
            self.assertEqual(1, len(first.json()["results"]))
            self.assertEqual(1, len(second.json()["results"]))
            self.assertNotEqual(
                first.json()["results"][0]["id"],
                second.json()["results"][0]["id"],
            )

    @async_test
    async def test_my_matches_requires_auth(self) -> None:
        app, _, _ = make_platform()
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            response = await client.get("/api/me/matches")
        self.assertEqual(401, response.status_code)

    @async_test
    async def test_leaderboard_aggregates(self) -> None:
        app, _, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin)
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            response = await client.get("/api/leaderboard")
        self.assertEqual(200, response.status_code)
        by_sub = {row["user_sub"]: row for row in response.json()["results"]}
        self.assertEqual(2, by_sub["alice"]["matches"])
        self.assertEqual(1, by_sub["alice"]["wins"])  # alice won match 1
        self.assertEqual(3.0, by_sub["alice"]["points"])  # 2.0 + 1.0
        self.assertEqual(1, by_sub["bob"]["wins"])  # bob won match 2
        self.assertEqual(4.0, by_sub["bob"]["points"])  # 1.0 + 3.0
        # Bob leads on points after tying Alice on wins.
        self.assertEqual("bob", response.json()["results"][0]["user_sub"])

    @async_test
    async def test_leaderboard_includes_elo_and_sorts_by_it(self) -> None:
        app, _, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin)
        ctx = await use_db(tortoise_mixin)
        with ctx:
            # Alice outranks everyone despite Bob leading on points.
            await PlayerRating.create(
                id=uuid.uuid4(),
                user_sub="alice",
                game_type="dummy",
                rating=1600,
                matches_played=2,
            )
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            response = await client.get("/api/leaderboard")
        self.assertEqual(200, response.status_code)
        results = response.json()["results"]
        by_sub = {row["user_sub"]: row for row in results}
        self.assertEqual(1600, by_sub["alice"]["elo"])
        # Players without a rating row report the initial rating.
        self.assertEqual(INITIAL_RATING, by_sub["bob"]["elo"])
        # Elo outranks wins/points.
        self.assertEqual("alice", results[0]["user_sub"])

    @async_test
    async def test_leaderboard_elo_scoped_by_game_type(self) -> None:
        app, platform, tortoise_mixin = make_platform(
            engines=(DummyEngine(), SecondEngine())
        )
        await _seed_two_matches(tortoise_mixin)
        ctx = await use_db(tortoise_mixin)
        with ctx:
            await PlayerRating.create(
                id=uuid.uuid4(),
                user_sub="bob",
                game_type="dummy",
                rating=1516,
                matches_played=1,
            )
            # Bob's rating in another game must not leak into the
            # dummy leaderboard.
            await PlayerRating.create(
                id=uuid.uuid4(),
                user_sub="bob",
                game_type="second",
                rating=1800,
                matches_played=1,
            )
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            response = await client.get("/api/leaderboard?game_type=dummy")
        self.assertEqual(200, response.status_code)
        results = response.json()["results"]
        by_sub = {row["user_sub"]: row for row in results}
        self.assertEqual(1516, by_sub["bob"]["elo"])
        self.assertEqual(INITIAL_RATING, by_sub["alice"]["elo"])
        self.assertEqual("second", platform.registry.all()[1].id)

    @async_test
    async def test_my_matches_include_elo_delta(self) -> None:
        app, platform, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        engine, session = _finished_session()
        engine.handle_action(session, "alice", "play", {})
        with ctx:
            await save_match_result(session, engine)
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            with oidc_user(platform.oidc, "alice"):
                response = await client.get("/api/me/matches")
        self.assertEqual(200, response.status_code)
        players = {
            p["user_sub"]: p
            for p in response.json()["results"][0]["players"]
        }
        self.assertEqual(16, players["alice"]["elo_delta"])
        self.assertEqual(-16, players["bob"]["elo_delta"])
        self.assertEqual(16, response.json()["results"][0]["your_elo_delta"])

    @async_test
    async def test_my_ratings_requires_auth(self) -> None:
        app, _, _ = make_platform()
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            response = await client.get("/api/me/ratings")
        self.assertEqual(401, response.status_code)

    @async_test
    async def test_my_ratings_returns_only_own_rows(self) -> None:
        app, platform, tortoise_mixin = make_platform()
        ctx = await use_db(tortoise_mixin)
        with ctx:
            await PlayerRating.create(
                id=uuid.uuid4(),
                user_sub="alice",
                game_type="dummy",
                rating=1516,
                matches_played=1,
            )
            await PlayerRating.create(
                id=uuid.uuid4(),
                user_sub="bob",
                game_type="dummy",
                rating=1484,
                matches_played=1,
            )
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            with oidc_user(platform.oidc, "alice"):
                response = await client.get("/api/me/ratings")
        self.assertEqual(200, response.status_code)
        self.assertEqual(
            [{"game_type": "dummy", "rating": 1516, "matches_played": 1}],
            response.json()["results"],
        )


class SecondEngine(DummyEngine):
    id = "second"
    name = "Second game"


class GameTypeFilterTest(unittest.TestCase):
    """Stats endpoints scope results by the match's game type."""

    @async_test
    async def test_my_matches_filter_by_game_type(self) -> None:
        # The second seed names a game the registry does not know; rows are
        # written directly, so this only exercises the SQL filter.
        app, platform, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin, game_types=("dummy", "other_game"))
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            with oidc_user(platform.oidc, "alice"):
                all_matches = await client.get("/api/me/matches")
                scoped = await client.get("/api/me/matches?game_type=dummy")
                unknown = await client.get("/api/me/matches?game_type=briscola")
            self.assertEqual(2, len(all_matches.json()["results"]))
            self.assertEqual(
                {"dummy", "other_game"},
                {m["game_type"] for m in all_matches.json()["results"]},
            )
            scoped_results = scoped.json()["results"]
            self.assertEqual(1, len(scoped_results))
            self.assertEqual("dummy", scoped_results[0]["game_type"])
            self.assertEqual(400, unknown.status_code)

    @async_test
    async def test_leaderboard_filter_by_game_type(self) -> None:
        app, platform, tortoise_mixin = make_platform()
        await _seed_two_matches(tortoise_mixin, game_types=("dummy", "other_game"))
        transport = ASGITransport(app=app)
        async with AsyncClient(transport=transport, base_url="http://127.0.0.1") as client:
            scoped = await client.get("/api/leaderboard?game_type=dummy")
            unknown = await client.get("/api/leaderboard?game_type=briscola")
        self.assertEqual(200, scoped.status_code)
        by_sub = {row["user_sub"]: row for row in scoped.json()["results"]}
        # Only the first match counts: one match per player, alice won.
        self.assertEqual(1, by_sub["alice"]["matches"])
        self.assertEqual(1, by_sub["alice"]["wins"])
        self.assertEqual(0, by_sub["bob"]["wins"])
        self.assertEqual(400, unknown.status_code)


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