#!/usr/bin/env python3

import importlib.util
import sys
import unittest
from pathlib import Path


PROJECT_ROOT = Path(__file__).resolve().parents[1]
MODULE_PATH = PROJECT_ROOT / "tools" / "performance-baseline.py"
SPEC = importlib.util.spec_from_file_location(
    "performance_baseline",
    MODULE_PATH,
)
MODULE = importlib.util.module_from_spec(SPEC)
assert SPEC.loader is not None
sys.modules[SPEC.name] = MODULE
SPEC.loader.exec_module(MODULE)


class StatisticsTests(unittest.TestCase):
    def test_percentile_interpolates_sorted_values(self):
        self.assertEqual(MODULE.percentile([40, 10, 30, 20], 50), 25)
        self.assertEqual(MODULE.percentile([10, 20], 95), 19.5)

    def test_percentile_rejects_empty_samples(self):
        with self.assertRaisesRegex(ValueError, "at least one"):
            MODULE.percentile([], 50)

    def test_summary_exposes_required_latency_percentiles(self):
        value = MODULE.summarize_ms([1.0, 2.0, 3.0, 20.0])
        self.assertEqual(value["samples"], 4)
        self.assertEqual(value["p50_ms"], 2.5)
        self.assertEqual(value["max_ms"], 20.0)


class TelemetryAnalysisTests(unittest.TestCase):
    def test_prefixed_telemetry_line_is_parsed(self):
        value = MODULE.parse_telemetry_line(
            '2026-10-14 INFO telemetry '
            '{"name":"ocr.scan","status":"ok","elapsed_ms":12.5}'
        )
        self.assertEqual(value["name"], "ocr.scan")
        self.assertEqual(value["elapsed_ms"], 12.5)

    def test_unrelated_or_invalid_lines_are_ignored(self):
        self.assertIsNone(MODULE.parse_telemetry_line("ordinary log line"))
        self.assertIsNone(MODULE.parse_telemetry_line("telemetry not-json"))
        self.assertIsNone(MODULE.parse_telemetry_line('{"elapsed_ms":12}'))

    def test_summary_ranks_stages_by_p95_and_counts_statuses(self):
        records = [
            {
                "name": "edge.ack.prepared",
                "status": "ok",
                "elapsed_ms": 2.0,
                "event_hash": "event-a",
            },
            {
                "name": "edge.ack.prepared",
                "status": "ok",
                "elapsed_ms": 4.0,
                "event_hash": "event-b",
            },
            {
                "name": "ocr.scan",
                "status": "ok",
                "elapsed_ms": 5000.0,
            },
            {
                "name": "ocr.scan",
                "status": "error",
                "elapsed_ms": "private-invalid-value",
            },
        ]

        value = MODULE.summarize_telemetry(records)

        self.assertEqual(value["records"], 4)
        self.assertEqual(value["events"], 2)
        self.assertEqual(value["stages"][0]["name"], "ocr.scan")
        self.assertEqual(value["stages"][1]["name"], "edge.ack.prepared")
        self.assertEqual(value["statuses"]["ocr.scan:error"], 1)


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