"""Tests for production shadow mode — Task 46."""

from __future__ import annotations

from datetime import datetime, timedelta, timezone

from services.intelligence_pipeline_v3.shadow.runner import (
    DisagreementLevel,
    ShadowComparison,
    ShadowConfig,
    ShadowRunner,
)


class TestShadowRunner:
    """Task 46.1-46.4: Shadow mode operation and stability."""

    def test_start_shadow(self):
        runner = ShadowRunner(config=ShadowConfig())
        assert not runner.is_active
        runner.start()
        assert runner.is_active

    def test_record_comparison(self):
        runner = ShadowRunner(config=ShadowConfig(enabled=True))
        runner.started_at = datetime.now(timezone.utc)
        comp = ShadowComparison.create(
            document_id="doc-001",
            v2_output={"sentiment": "positive"},
            v3_output={"sentiment": "positive"},
            disagreement_level=DisagreementLevel.NONE,
        )
        runner.record_comparison(comp)
        assert runner.documents_processed == 1

    def test_critical_disagreements_tracked(self):
        runner = ShadowRunner(config=ShadowConfig(enabled=True))
        runner.started_at = datetime.now(timezone.utc)
        for i in range(3):
            runner.record_comparison(
                ShadowComparison.create(
                    document_id=f"doc-{i}",
                    v2_output={},
                    v3_output={},
                    disagreement_level=DisagreementLevel.CRITICAL,
                )
            )
        assert runner.critical_disagreements == 3

    def test_major_disagreement_rate(self):
        runner = ShadowRunner(config=ShadowConfig(enabled=True))
        runner.started_at = datetime.now(timezone.utc)
        # 2 major out of 10 = 20%
        for i in range(8):
            runner.record_comparison(
                ShadowComparison.create(
                    f"doc-{i}", {}, {},
                    disagreement_level=DisagreementLevel.MINOR,
                )
            )
        for i in range(2):
            runner.record_comparison(
                ShadowComparison.create(
                    f"doc-major-{i}", {}, {},
                    disagreement_level=DisagreementLevel.MAJOR,
                )
            )
        assert runner.major_disagreement_rate == 0.2

    def test_promotion_requires_min_duration(self):
        config = ShadowConfig(
            enabled=True,
            min_duration=timedelta(days=7),
            min_documents=10,
        )
        runner = ShadowRunner(config=config)
        runner.started_at = datetime.now(timezone.utc)  # Just started
        for i in range(20):
            runner.record_comparison(
                ShadowComparison.create(f"doc-{i}", {}, {})
            )
        # Not enough time elapsed
        assert not runner.meets_promotion_criteria()

    def test_promotion_requires_min_documents(self):
        config = ShadowConfig(
            enabled=True,
            min_duration=timedelta(seconds=0),
            min_documents=100,
        )
        runner = ShadowRunner(config=config)
        runner.started_at = datetime.now(timezone.utc) - timedelta(days=10)
        for i in range(50):  # Below minimum
            runner.record_comparison(
                ShadowComparison.create(f"doc-{i}", {}, {})
            )
        assert not runner.meets_promotion_criteria()

    def test_promotion_criteria_met(self):
        config = ShadowConfig(
            enabled=True,
            min_duration=timedelta(seconds=0),
            min_documents=5,
            max_critical_disagreements=10,
            max_major_disagreement_rate=0.5,
        )
        runner = ShadowRunner(config=config)
        runner.started_at = datetime.now(timezone.utc) - timedelta(days=10)
        for i in range(10):
            runner.record_comparison(
                ShadowComparison.create(f"doc-{i}", {}, {})
            )
        assert runner.meets_promotion_criteria()

    def test_fast_path_rate_tracking(self):
        runner = ShadowRunner(config=ShadowConfig(enabled=True))
        runner.started_at = datetime.now(timezone.utc)
        runner.record_processing(fast_path=True)
        runner.record_processing(fast_path=True)
        runner.record_processing(fast_path=False)
        assert runner.fast_path_rate == pytest.approx(2 / 3)

    def test_auto_disable_on_errors(self):
        config = ShadowConfig(
            enabled=True, auto_disable_on_errors=True, error_threshold=3
        )
        runner = ShadowRunner(config=config)
        runner.started_at = datetime.now(timezone.utc)
        for _ in range(3):
            runner.record_error()
        assert not runner.is_active

    def test_get_review_sample(self):
        runner = ShadowRunner(
            config=ShadowConfig(enabled=True, sample_review_rate=0.5)
        )
        runner.started_at = datetime.now(timezone.utc)
        for i in range(4):
            runner.record_comparison(
                ShadowComparison.create(
                    f"doc-{i}", {}, {},
                    disagreement_level=DisagreementLevel.MODERATE,
                    risk_score=0.5 + i * 0.1,
                )
            )
        sample = runner.get_review_sample()
        assert len(sample) == 2  # 50% of 4
        # Should be sorted by priority/risk
        assert sample[0].risk_score >= sample[1].risk_score

    def test_summary(self):
        runner = ShadowRunner(config=ShadowConfig(enabled=True))
        runner.started_at = datetime.now(timezone.utc)
        summary = runner.summary()
        assert summary["active"] is True
        assert "documents_processed" in summary


# Need this import for pytest.approx
import pytest  # noqa: E402