import unittest
from io import BytesIO
from types import SimpleNamespace
from unittest.mock import patch

import cv2

from ffmpeg_capture import FFmpegCapture, _parse_float, _parse_int, _parse_rate
from helpers import open_source


class FFmpegCaptureTests(unittest.TestCase):
    def test_parse_fractional_rate(self):
        self.assertAlmostEqual(_parse_rate("30000/1001"), 29.97002997)

    def test_parse_invalid_rate(self):
        self.assertEqual(_parse_rate("0/0"), 0.0)
        self.assertEqual(_parse_rate("unknown"), 0.0)

    def test_unknown_frame_count_and_duration_are_zero(self):
        self.assertEqual(_parse_int("N/A"), 0)
        self.assertEqual(_parse_int(None), 0)
        self.assertEqual(_parse_float("N/A"), 0.0)

    def test_raw_reader_does_not_duplicate_frames(self):
        cap = FFmpegCapture.__new__(FFmpegCapture)
        cap.source = "source.mp4"
        cap.width = 640
        cap.height = 480
        with patch("ffmpeg_capture.subprocess.Popen") as popen:
            cap._start()
        command = popen.call_args.args[0]
        self.assertEqual(command[command.index("-vsync") + 1], "0")

    def test_reads_buffered_frame_after_ffmpeg_process_exits(self):
        cap = FFmpegCapture.__new__(FFmpegCapture)
        cap.width = 1
        cap.height = 1
        cap.frames_read = 0
        cap.process = SimpleNamespace(
            stdout=BytesIO(b"\x01\x02\x03"),
            poll=lambda: 0,
        )

        ok, frame = cap.read()

        self.assertTrue(ok)
        self.assertEqual(frame.shape, (1, 1, 3))
        self.assertEqual(frame.tolist(), [[[1, 2, 3]]])

    @patch("helpers.FFmpegCapture")
    def test_open_source_creates_ffmpeg_reader_with_file_path_only(self, capture):
        reader = SimpleNamespace(isOpened=lambda: True)
        capture.return_value = reader

        opened, source_kind = open_source("clip.avi", cv2.CAP_FFMPEG)

        capture.assert_called_once_with("clip.avi")
        self.assertIs(opened, reader)
        self.assertEqual(source_kind, "file")


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