import unittest
from datetime import datetime, timezone

from fault_log_analyzer.parser import parse_log, parse_timestamp, templatize, tokenize


class TestParseTimestamp(unittest.TestCase):
    def test_iso_with_z(self):
        dt = parse_timestamp("2025-01-01T10:18:00Z")
        self.assertEqual(dt.year, 2025)
        self.assertEqual(dt.minute, 18)

    def test_epoch_seconds(self):
        dt = parse_timestamp(1735726680)  # 2025-01-01T10:18:00Z
        self.assertEqual(dt.year, 2025)

    def test_epoch_millis(self):
        dt = parse_timestamp(1735726680000)
        self.assertEqual(dt.year, 2025)

    def test_common_format(self):
        dt = parse_timestamp("2025-01-01 10:18:00")
        self.assertEqual(dt.year, 2025)
        self.assertEqual(dt.hour, 10)

    def test_invalid_returns_none(self):
        self.assertIsNone(parse_timestamp("not-a-date"))


class TestParseLog(unittest.TestCase):
    def test_structured_json(self):
        raw = {
            "timestamp": "2025-01-01T10:18:00Z",
            "level": "ERROR",
            "message": "No space left on device",
            "host_id": "h-001",
            "service": "app",
            "trace_id": "tr-1",
        }
        entry = parse_log(raw)
        self.assertEqual(entry.level, "ERROR")
        self.assertEqual(entry.host_id, "h-001")
        self.assertEqual(entry.trace_id, "tr-1")

    def test_level_extracted_from_message(self):
        entry = parse_log({"message": "ERROR: something bad"})
        self.assertEqual(entry.level, "ERROR")

    def test_json_message_expands_fields(self):
        raw = {"message": '{"message": "disk full", "level": "FATAL", "host_id": "h-2"}'}
        entry = parse_log(raw)
        self.assertEqual(entry.message, "disk full")
        self.assertEqual(entry.level, "FATAL")
        self.assertEqual(entry.host_id, "h-2")


class TestTemplatize(unittest.TestCase):
    def test_replace_variables(self):
        msg = "Connection from 10.0.0.11 port 8080 failed after 3 retries"
        tpl = templatize(msg)
        self.assertIn("<IP>", tpl)
        self.assertIn("<NUM>", tpl)

    def test_replace_uuid(self):
        tpl = templatize("request 123e4567-e89b-12d3-a456-426614174000 failed")
        self.assertIn("<UUID>", tpl)

    def test_tokenize(self):
        tokens = tokenize("No space left on device")
        self.assertIn("space", tokens)
        self.assertIn("device", tokens)


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