"""根因分析（RootCauseAnalyzer）单元测试。"""
import _bootstrap  # noqa: F401
import unittest
from datetime import datetime, timedelta, timezone

from fault_log_analyzer.models import Event, FaultLog
from fault_log_analyzer.root_cause import RootCauseAnalyzer, _as_aware

BASE = datetime(2025, 1, 1, 10, 0, 0, tzinfo=timezone.utc)
NAIVE_BASE = datetime(2025, 1, 1, 10, 0, 0)


def _log(message, occurred_at=BASE, host_id="h-1", fault_log_id="fl-1"):
    return FaultLog(
        fault_log_id=fault_log_id,
        host_id=host_id,
        message=message,
        level="ERROR",
        occurred_at=occurred_at,
    )


class TestAsAware(unittest.TestCase):
    def test_aware_kept(self):
        self.assertEqual(_as_aware(BASE), BASE)

    def test_naive_becomes_utc(self):
        out = _as_aware(NAIVE_BASE)
        self.assertEqual(out.tzinfo, timezone.utc)
        self.assertEqual(out, BASE)

    def test_none(self):
        self.assertIsNone(_as_aware(None))


class TestRootCauseAnalyzer(unittest.TestCase):
    def setUp(self):
        self.analyzer = RootCauseAnalyzer(window_minutes=5)

    def test_log_hint_only(self):
        rc = self.analyzer.analyze(_log("No space left on device /var"), [])
        self.assertEqual(rc.cause_type, "disk_full")
        self.assertEqual(rc.confidence, 0.6)
        self.assertEqual(rc.fault_log_id, "fl-1")

    def test_unknown_without_evidence(self):
        rc = self.analyzer.analyze(_log("some unrelated message"), [])
        self.assertEqual(rc.cause_type, "unknown")
        self.assertEqual(rc.confidence, 0.0)

    def test_matching_event_corroborates(self):
        event = Event(
            event_id="e-1",
            host_id="h-1",
            metric="disk_used_percent",
            value=97.2,
            threshold=90.0,
            fired_at=BASE,
        )
        rc = self.analyzer.analyze(_log("No space left on device"), [event])
        self.assertEqual(rc.cause_type, "disk_full")
        # 0.6（日志） + 0.25（指标） + 0.15（互相印证） = 1.0
        self.assertEqual(rc.confidence, 1.0)
        self.assertTrue(any(e["type"] == "event" and e["event_id"] == "e-1" for e in rc.evidence))

    def test_naive_datetime_aware_event(self):
        """naive 日志时间 + aware 事件时间混用不应抛异常（鲁棒性）。"""
        event = Event(
            event_id="e-1",
            host_id="h-1",
            metric="mem_used_percent",
            value=95.0,
            threshold=90.0,
            fired_at=BASE,
        )
        rc = self.analyzer.analyze(_log("out of memory", occurred_at=NAIVE_BASE), [event])
        self.assertEqual(rc.cause_type, "memory_exhausted")
        self.assertEqual(rc.confidence, 1.0)

    def test_naive_event_outside_window(self):
        """窗口外的 naive 事件不应被关联，也不应抛异常（鲁棒性）。"""
        outside = Event(
            event_id="e-1",
            host_id="h-1",
            metric="disk_used_percent",
            value=97.2,
            threshold=90.0,
            fired_at=NAIVE_BASE + timedelta(hours=1),
        )
        rc = self.analyzer.analyze(_log("No space left on device"), [outside])
        self.assertEqual(rc.cause_type, "disk_full")
        self.assertEqual(rc.confidence, 0.6)
        self.assertEqual(len(rc.evidence), 1)  # 仅日志证据，无事件证据

    def test_host_mismatch_excluded(self):
        event = Event(
            event_id="e-1",
            host_id="h-other",
            metric="disk_used_percent",
            value=97.2,
            threshold=90.0,
            fired_at=BASE,
        )
        rc = self.analyzer.analyze(_log("No space left on device"), [event])
        self.assertEqual(rc.cause_type, "disk_full")
        self.assertEqual(rc.confidence, 0.6)

    def test_event_only_cause(self):
        """日志无关键字但事件命中规则库时，以事件规则为准。"""
        event = Event(
            event_id="e-1",
            host_id="h-1",
            metric="cpu_usage",
            value=99.0,
            threshold=95.0,
            fired_at=BASE,
        )
        rc = self.analyzer.analyze(_log("service degraded"), [event])
        self.assertEqual(rc.cause_type, "cpu_saturation")
        self.assertEqual(rc.confidence, 0.25)


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