"""Unit tests for consecutive-failure Sentry alert in scrape_runs.

All tests use a fully mocked DB session — no live DB required.
The mock simulates db.execute(...).fetchall() and db.execute(...).fetchone()
to control which run statuses are returned for the query in
_alert_if_consecutive_failures / _alert_on_run_id.
"""

from __future__ import annotations

from types import SimpleNamespace
from unittest.mock import MagicMock, patch

from app.services.scrape_runs import (
    CONSECUTIVE_FAILURE_ALERT_THRESHOLD,
    _alert_if_consecutive_failures,
    mark_banned,
    mark_failed,
)

N = CONSECUTIVE_FAILURE_ALERT_THRESHOLD  # 3


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


def _make_rows(*statuses: str) -> list[SimpleNamespace]:
    """Build a list of fake row objects with .status attribute."""
    return [SimpleNamespace(status=s) for s in statuses]


def _make_db(streak_rows: list[SimpleNamespace]) -> MagicMock:
    """Return a mock Session whose execute().fetchall() returns streak_rows."""
    execute_result = MagicMock()
    execute_result.fetchall.return_value = streak_rows
    db = MagicMock()
    db.execute.return_value = execute_result
    return db


# ---------------------------------------------------------------------------
# _alert_if_consecutive_failures — unit tests
# ---------------------------------------------------------------------------


class TestAlertIfConsecutiveFailures:
    def test_no_alert_when_fewer_than_n_runs(self) -> None:
        """< N finished runs → no alert regardless of status."""
        db = _make_db(_make_rows(*["failed"] * (N - 1)))
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_not_called()

    def test_no_alert_when_streak_is_n_minus_1(self) -> None:
        """N-1 consecutive failures (plus one older success) → no alert."""
        # Rows ordered newest-first: N-1 failures, then one 'done'
        rows = _make_rows(*["failed"] * (N - 1), "done")
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_not_called()

    def test_alert_fires_exactly_at_n(self) -> None:
        """Exactly N consecutive failures (no older run) → alert sent once."""
        rows = _make_rows(*["failed"] * N)
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_called_once()
        (msg,) = mock_sentry.capture_message.call_args.args
        assert "avito" in msg
        assert str(N) in msg

    def test_alert_fires_with_mixed_failed_banned(self) -> None:
        """Mix of 'failed' and 'banned' within N streak → alert sent."""
        rows = _make_rows("banned", "failed", "banned")
        assert len(rows) == N
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "cian")
        mock_sentry.capture_message.assert_called_once()

    def test_alert_fires_when_n_plus_1_is_done(self) -> None:
        """N failures newest + 1 older 'done' → alert (streak just reached N)."""
        rows = _make_rows(*["failed"] * N, "done")
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "yandex")
        mock_sentry.capture_message.assert_called_once()

    def test_no_alert_when_n_plus_1_is_also_failed(self) -> None:
        """N failures newest + 1 older 'failed' → no alert (streak > N, already fired)."""
        rows = _make_rows(*["failed"] * (N + 1))
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_not_called()

    def test_no_alert_when_first_n_has_success(self) -> None:
        """If any of the N newest runs is 'done' → no alert."""
        # 2 failures then 1 success in newest N
        rows = _make_rows("failed", "done", "failed")
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_not_called()

    def test_sentry_exception_does_not_propagate(self) -> None:
        """If sentry_sdk.capture_message raises, the function must NOT raise."""
        rows = _make_rows(*["failed"] * N)
        db = _make_db(rows)
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            mock_sentry.capture_message.side_effect = RuntimeError("sentry down")
            # Should not raise
            _alert_if_consecutive_failures(db, "avito")

    def test_db_query_exception_does_not_propagate(self) -> None:
        """If db.execute raises, the function must NOT raise."""
        db = MagicMock()
        db.execute.side_effect = Exception("connection lost")
        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            _alert_if_consecutive_failures(db, "avito")
        mock_sentry.capture_message.assert_not_called()


# ---------------------------------------------------------------------------
# mark_failed / mark_banned integration — verify alert hook is called
# ---------------------------------------------------------------------------


def _make_db_for_mark(source: str, streak_rows: list[SimpleNamespace]) -> MagicMock:
    """Mock DB for mark_failed/mark_banned.

    Sequence of execute() calls in mark_failed:
      1. UPDATE scrape_runs SET status='failed' ... RETURNING id  → .first()
      2. (after rollback) SELECT source FROM scrape_runs WHERE id=... → .fetchone()
      3. SELECT status FROM scrape_runs WHERE source=... LIMIT N+1 → .fetchall()
    """
    db = MagicMock()

    # Call 1 (mark_failed UPDATE): .first() returns a row with id
    update_result = MagicMock()
    update_result.first.return_value = SimpleNamespace(id=42)

    # Call 2 (_alert_on_run_id SELECT source): .fetchone() returns source row
    source_result = MagicMock()
    source_result.fetchone.return_value = SimpleNamespace(source=source)

    # Call 3 (_alert_if_consecutive_failures SELECT statuses): .fetchall()
    streak_result = MagicMock()
    streak_result.fetchall.return_value = streak_rows

    db.execute.side_effect = [update_result, source_result, streak_result]
    return db


class TestMarkFailedAlertIntegration:
    def test_mark_failed_triggers_alert_on_nth_failure(self) -> None:
        """mark_failed integrates with alert helper: alert fires on Nth streak."""
        rows = _make_rows(*["failed"] * N)
        db = _make_db_for_mark("avito", rows)

        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            mark_failed(db, 42, "timeout", {})

        mock_sentry.capture_message.assert_called_once()

    def test_mark_failed_no_alert_below_threshold(self) -> None:
        """mark_failed: no alert when streak < N."""
        rows = _make_rows(*["failed"] * (N - 1))
        db = _make_db_for_mark("avito", rows)

        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            mark_failed(db, 42, "timeout", {})

        mock_sentry.capture_message.assert_not_called()


class TestMarkBannedAlertIntegration:
    def test_mark_banned_triggers_alert_on_nth_failure(self) -> None:
        """mark_banned integrates with alert helper: alert fires on Nth streak."""
        rows = _make_rows(*["banned"] * N)
        # Reuse the same mock builder — mark_banned has same execute sequence
        db = _make_db_for_mark("cian", rows)

        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            mark_banned(db, 42, "403 Forbidden", {})

        mock_sentry.capture_message.assert_called_once()
        (msg,) = mock_sentry.capture_message.call_args.args
        assert "cian" in msg

    def test_mark_banned_no_alert_below_threshold(self) -> None:
        """mark_banned: no alert when streak < N."""
        rows = _make_rows(*["banned"] * (N - 1))
        db = _make_db_for_mark("cian", rows)

        with patch("app.services.scrape_runs.sentry_sdk") as mock_sentry:
            mark_banned(db, 42, "403 Forbidden", {})

        mock_sentry.capture_message.assert_not_called()