"""Tests of the flash card view model over a real session and in-memory deck."""

from collections.abc import Sequence

from flash_card.application.use_cases.study_session import StudySession
from flash_card.constants import FINISHED_MESSAGE
from flash_card.domain.entities.card import Card
from flash_card.domain.entities.deck import Deck
from flash_card.domain.value_objects.language_pair import LanguagePair
from flash_card.presentation.features.flash_card.flash_card_view_model import (
    FlashCardViewModel,
    Side,
)

A = Card("aku", "mig")
B = Card("kau", "du")


def _first(cards: Sequence[Card]) -> Card:
    return cards[0]


class _RecordingProgress:
    def __init__(self) -> None:
        self.saved: list[tuple[Card, ...]] = []

    def load(self) -> Deck | None:
        return None

    def save(self, deck: Deck) -> None:
        self.saved.append(deck.cards)


def _session(
    code: str, *cards: Card, progress: _RecordingProgress | None = None
) -> StudySession:
    store = _RecordingProgress() if progress is None else progress
    return StudySession(Deck(LanguagePair(code, "da"), cards), _first, store)


def test_view_model_draws_first_card_on_construction() -> None:
    view_model = FlashCardViewModel(_session("ms", A, B))
    assert view_model.text == "aku"
    assert view_model.language_name == "Malay"
    assert not view_model.is_finished


def test_next_card_shows_next_card() -> None:
    view_model = FlashCardViewModel(_session("ms", A, B))
    view_model.next_card()
    assert view_model.text == "kau"


def test_language_name_shows_unknown_code_in_upper_case() -> None:
    view_model = FlashCardViewModel(_session("xx", A))
    assert view_model.language_name == "XX"


def test_language_name_uses_given_names() -> None:
    view_model = FlashCardViewModel(_session("ms", A), {"ms": "Melayu"})
    assert view_model.language_name == "Melayu"


def test_view_model_shows_finished_message_when_no_card_is_left() -> None:
    view_model = FlashCardViewModel(_session("ms"))
    assert view_model.is_finished
    assert view_model.language_name == ""
    assert view_model.text == FINISHED_MESSAGE


def test_view_model_starts_on_front_side() -> None:
    view_model = FlashCardViewModel(_session("ms", A))
    assert view_model.side is Side.FRONT


def test_flip_card_shows_back_language_and_translation() -> None:
    view_model = FlashCardViewModel(_session("ms", A))
    view_model.flip_card()
    assert view_model.side is Side.BACK
    assert view_model.language_name == "Danish"
    assert view_model.text == "mig"


def test_flip_card_twice_keeps_back_side() -> None:
    view_model = FlashCardViewModel(_session("ms", A))
    view_model.flip_card()
    view_model.flip_card()
    assert view_model.side is Side.BACK
    assert view_model.text == "mig"


def test_flip_card_does_nothing_when_finished() -> None:
    view_model = FlashCardViewModel(_session("ms"))
    view_model.flip_card()
    assert view_model.side is Side.FRONT
    assert view_model.language_name == ""
    assert view_model.text == FINISHED_MESSAGE


def test_next_card_resets_side_to_front() -> None:
    view_model = FlashCardViewModel(_session("ms", A, B))
    view_model.flip_card()
    view_model.next_card()
    assert view_model.side is Side.FRONT
    assert view_model.language_name == "Malay"
    assert view_model.text == "kau"


def test_is_known_saves_remaining_and_shows_next_front() -> None:
    progress = _RecordingProgress()
    view_model = FlashCardViewModel(_session("ms", A, B, progress=progress))
    view_model.flip_card()
    view_model.is_known()
    assert progress.saved == [(B,)]
    assert view_model.side is Side.FRONT
    assert view_model.text == "kau"
    assert not view_model.is_finished


def test_is_known_on_last_card_finishes() -> None:
    progress = _RecordingProgress()
    view_model = FlashCardViewModel(_session("ms", A, progress=progress))
    view_model.is_known()
    assert view_model.is_finished
    assert view_model.text == FINISHED_MESSAGE
    assert progress.saved == [()]


def test_is_known_does_nothing_when_finished() -> None:
    progress = _RecordingProgress()
    view_model = FlashCardViewModel(_session("ms", progress=progress))
    view_model.is_known()
    assert view_model.is_finished
    assert progress.saved == []


def test_next_card_does_nothing_when_finished() -> None:
    view_model = FlashCardViewModel(_session("ms"))
    view_model.next_card()
    assert view_model.is_finished
    assert view_model.text == FINISHED_MESSAGE


def test_next_card_never_saves() -> None:
    progress = _RecordingProgress()
    view_model = FlashCardViewModel(_session("ms", A, B, progress=progress))
    view_model.next_card()
    assert progress.saved == []