"""Tests for cht.stream.tracker — RecordingTracker."""

import time
from pathlib import Path
from unittest.mock import patch, MagicMock

import pytest

from cht.stream.tracker import RecordingTracker


class TestRecordingTracker:
    def test_initial_duration_is_zero(self):
        tracker = RecordingTracker(get_segments=lambda: [])
        assert tracker.duration == 0.0

    def test_callback_called_on_update(self, tmp_path):
        seg = tmp_path / "rec.mp4"
        seg.write_bytes(b"\x00" * 100_000)

        cb = MagicMock()
        tracker = RecordingTracker(
            get_segments=lambda: [seg],
            on_duration_update=cb,
        )
        with patch.object(tracker, "_probe_duration", return_value=10.0):
            tracker.start()
            time.sleep(3)
            tracker.stop()

        cb.assert_called()
        assert cb.call_args[0][0] > 0

    def test_no_callback_if_no_segments(self):
        cb = MagicMock()
        tracker = RecordingTracker(get_segments=lambda: [], on_duration_update=cb)
        tracker.start()
        time.sleep(3)
        tracker.stop()
        cb.assert_not_called()

    def test_no_callback_if_file_missing(self, tmp_path):
        cb = MagicMock()
        tracker = RecordingTracker(
            get_segments=lambda: [tmp_path / "nonexistent.mp4"],
            on_duration_update=cb,
        )
        tracker.start()
        time.sleep(3)
        tracker.stop()
        cb.assert_not_called()

    def test_duration_only_increases(self, tmp_path):
        seg = tmp_path / "rec.mp4"
        seg.write_bytes(b"\x00" * 100_000)
        durations = []

        def on_update(d):
            durations.append(d)

        probe_values = iter([5.0, 3.0, 7.0])  # 3.0 is a regression — should be ignored

        tracker = RecordingTracker(
            get_segments=lambda: [seg],
            on_duration_update=on_update,
        )
        with patch.object(tracker, "_probe_duration", side_effect=probe_values):
            tracker.start()
            time.sleep(7)
            tracker.stop()

        # Duration should never go backwards
        for i in range(1, len(durations)):
            assert durations[i] >= durations[i - 1], "Duration regressed"