import _bootstrap  # noqa: F401

import unittest
from datetime import datetime, timezone

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


def make_log(message="No space left on device", fid="fl-1", host="h-1", trace_id=""):
    return FaultLog(
        fault_log_id=fid,
        host_id=host,
        fingerprint="fp",
        level="ERROR",
        message=message,
        occurred_at=datetime(2025, 1, 1, 10, 0, 0, tzinfo=timezone.utc),
        trace_id=trace_id,
    )


def make_event(event_id="e-1", host="h-1", metric="disk_used_percent", value=97.2, minute=1):
    return Event(
        event_id=event_id,
        host_id=host,
        metric=metric,
        value=value,
        fired_at=datetime(2025, 1, 1, 10, minute, 0, tzinfo=timezone.utc),
    )


class TestRootCauseRule(unittest.TestCase):
    def test_match_log(self):
        rule = RootCauseRule("disk_full", r"no space left on device")
        self.assertTrue(rule.match_log("No space left on device"))
        self.assertFalse(rule.match_log("connection refused"))

    def test_match_metric_threshold(self):
        rule = RootCauseRule("disk_full", metric_pattern=r"disk.*used", metric_threshold=90.0)
        self.assertTrue(rule.match_metric("disk_used_percent", 95.0))
        self.assertFalse(rule.match_metric("disk_used_percent", 80.0))
        self.assertFalse(rule.match_metric("cpu_usage", 95.0))


class TestRootCauseAnalyzer(unittest.TestCase):
    def test_disk_full_with_metric_event(self):
        rc = RootCauseAnalyzer().analyze(
            make_log("No space left on device"),
            [make_event()],
        )
        self.assertEqual(rc.cause_type, "disk_full")
        self.assertGreaterEqual(rc.confidence, 0.95)
        self.assertTrue(any(e.type == "event" for e in rc.evidence))
        self.assertTrue(any(e.type == "log" for e in rc.evidence))

    def test_rule_without_matching_event(self):
        rc = RootCauseAnalyzer().analyze(
            make_log("No space left on device"),
            [make_event(metric="cpu_usage", value=80.0)],
        )
        self.assertEqual(rc.cause_type, "disk_full")
        # 日志规则命中但指标事件不匹配，置信度为基础值
        self.assertAlmostEqual(rc.confidence, 0.95)

    def test_unknown_with_related_event(self):
        rc = RootCauseAnalyzer().analyze(
            make_log("mysterious failure"),
            [make_event(metric="cpu_usage", value=50.0)],
        )
        self.assertEqual(rc.cause_type, "related_cpu_usage")
        self.assertEqual(rc.confidence, 0.4)

    def test_unknown_with_trace_only(self):
        rc = RootCauseAnalyzer().analyze(make_log("mysterious failure", trace_id="t-1"), [])
        self.assertEqual(rc.cause_type, "trace_linked")
        self.assertEqual(rc.confidence, 0.3)

    def test_event_out_of_window_ignored(self):
        old_event = make_event(event_id="e-old", minute=20)  # 超出 ±5 分钟窗口
        rc = RootCauseAnalyzer().analyze(make_log("No space left on device"), [old_event])
        # 日志规则仍命中，但没有指标事件证据增强
        self.assertEqual(rc.cause_type, "disk_full")
        self.assertFalse(any(e.type == "event" for e in rc.evidence))


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