"""
Тесты для update_skill_mastery.
Проверяют формулы расчёта mastery, retention, trend.
"""
import pytest
from datetime import datetime, timedelta


# ─────────────────────────────────────────────
# ХЕЛПЕР: вставить ответ напрямую в БД
# ─────────────────────────────────────────────

async def insert_answer(
    conn,
    user_id: int,
    session_id: int,
    skill_tag: str,
    correct: bool,
    question_type: str = "recognition",
    wrong_because: str | None = None,
    days_ago: int = 0,
):
    """Вставляет один ответ в user_learning_answers."""
    created_at = datetime.now() - timedelta(days=days_ago)
    await conn.execute("""
        INSERT INTO user_learning_answers (
            user_id, session_id, level_code, topic_id, question_id,
            selected_answer, correct, skill_tag, question_type,
            context_type, difficulty, time_taken_ms, hint_used,
            wrong_because, is_final_answer, created_at
        ) VALUES (
            $1, $2, 'A2', 'test_topic', 'test_q', 
            'x', $3, $4, $5, 
            'lesson_practice', 1, 5000, FALSE, 
            $6, TRUE, $7
        )
    """, user_id, session_id, correct, skill_tag, question_type, wrong_because, created_at)


# ─────────────────────────────────────────────
# ТЕСТЫ
# ─────────────────────────────────────────────

async def test_mastery_no_answers_returns_none(conn, test_user, clean_mastery):
    """Если у юзера нет ответов по skill_tag — функция возвращает None."""
    from routers.learning import update_skill_mastery
    
    result = await update_skill_mastery(conn, test_user, "nonexistent_skill")
    assert result is None


async def test_mastery_100_percent_accuracy(conn, test_user, test_session, clean_mastery):
    """Если все ответы правильные — accuracy = 100, mastery = высокая."""
    from routers.learning import update_skill_mastery
    
    for _ in range(5):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=True)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result is not None
    assert result["attempts"] == 5
    assert result["accuracy"] == 100.0
    assert result["mastery"] >= 90.0


async def test_mastery_0_percent_accuracy(conn, test_user, test_session, clean_mastery):
    """Если все ответы неправильные — accuracy = 0, mastery = низкая."""
    from routers.learning import update_skill_mastery
    
    for _ in range(5):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=False, wrong_because="wrong_case")
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result is not None
    assert result["accuracy"] == 0.0
    assert result["mastery"] <= 30.0


async def test_mastery_50_percent_accuracy(conn, test_user, test_session, clean_mastery):
    """50% accuracy → mastery в среднем диапазоне."""
    from routers.learning import update_skill_mastery
    
    for i in range(6):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=(i % 2 == 0))
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result is not None
    assert 40.0 <= result["accuracy"] <= 60.0
    assert 40.0 <= result["mastery"] <= 80.0


async def test_mastery_retention_fresh(conn, test_user, test_session, clean_mastery):
    """Если последний ответ был сегодня — retention_status = 'fresh'."""
    from routers.learning import update_skill_mastery
    
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=0)
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=0)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result["retention_status"] == "fresh"


async def test_mastery_retention_needs_review(conn, test_user, test_session, clean_mastery):
    """Если последний ответ 10 дней назад — retention_status = 'needs_review'."""
    from routers.learning import update_skill_mastery
    
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=10)
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=10)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result["retention_status"] == "needs_review"


async def test_mastery_retention_overdue(conn, test_user, test_session, clean_mastery):
    """Если последний ответ 20 дней назад — retention_status = 'overdue'."""
    from routers.learning import update_skill_mastery
    
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=20)
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=20)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result["retention_status"] == "overdue"


async def test_mastery_trend_improving(conn, test_user, test_session, clean_mastery):
    """Если последние 3 ответа лучше, чем общая точность — trend = 'improving'."""
    from routers.learning import update_skill_mastery
    
    # 7 старых неправильных, 3 свежих правильных
    for _ in range(7):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=False, days_ago=5)
    for _ in range(3):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=0)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    # 3 правильных из 10 = 30% accuracy, но recent_accuracy = 100% → improving
    assert result["trend"] == "improving"


async def test_mastery_trend_declining(conn, test_user, test_session, clean_mastery):
    """Если последние 3 ответа хуже, чем общая точность — trend = 'declining'."""
    from routers.learning import update_skill_mastery
    
    # 7 старых правильных, 3 свежих неправильных
    for _ in range(7):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=True, days_ago=5)
    for _ in range(3):
        await insert_answer(conn, test_user, test_session, "test_skill", correct=False, days_ago=0)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result["trend"] == "declining"


async def test_mastery_trend_insufficient_data(conn, test_user, test_session, clean_mastery):
    """Если меньше 3 ответов — trend = 'insufficient_data'."""
    from routers.learning import update_skill_mastery
    
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True)
    await insert_answer(conn, test_user, test_session, "test_skill", correct=True)
    
    result = await update_skill_mastery(conn, test_user, "test_skill")
    
    assert result["trend"] == "insufficient_data"