"""Verifies clap detection analyzes whichever audio track mpv is actually
playing, not whichever one ffmpeg's own default-stream heuristic would
pick. Uses a synthetic fixture with two audio tracks with claps at very
different times (3s vs 7s) -- if detection ignored mpv's active track
selection, switching mpv to the second track would still incorrectly
report the first track's 3s clap instead of the second track's 7s one.

This directly tests the bug hypothesis from user report: 'sometimes too
early, sometimes too late, by different amounts' -- exactly what you'd
see if detection sometimes analyzed the wrong audio track on
multi-audio-track files, since a wrong-track clap position is essentially
unrelated to the true one (not a small timestamp-math error).
"""
import sys
import time
from pathlib import Path

from PyQt6.QtWidgets import QApplication

sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
import main as app_main

ROOT = Path(__file__).resolve().parent.parent
CLIP = str(ROOT / "test_media" / "sync_test_MULTITRACK.mp4")


def wait_for(predicate, qapp, timeout=20):
    deadline = time.time() + timeout
    while not predicate() and time.time() < deadline:
        qapp.processEvents()
        time.sleep(0.05)
    return predicate()


def main():
    qapp = QApplication(sys.argv)
    win = app_main.MainWindow()
    win.show()
    qapp.processEvents()

    win._load(CLIP)
    qapp.processEvents()
    time.sleep(0.3)
    qapp.processEvents()

    mpv = win.source_panel.player.mpv
    print(f"default aid: {mpv.aid}")
    default_index = win._current_audio_stream_index()
    print(f"resolved ff-index for default track: {default_index}")
    assert default_index == 1, f"expected default track's ff-index to be 1, got {default_index}"

    win.detect_all_button.click()
    qapp.processEvents()
    ok = wait_for(lambda: win.detect_all_button.isEnabled(), qapp)
    assert ok, "detection did not finish in time"
    markers = win.source_panel.marker_strip.markers()
    print(f"markers with default track selected: {markers}")
    assert any(abs(m - 3.0) < 0.5 for m in markers), f"expected a marker near 3.0s (default track's clap): {markers}"
    assert not any(abs(m - 7.0) < 0.5 for m in markers), f"should not see the OTHER track's 7.0s clap yet: {markers}"

    # Now switch mpv to the second audio track (aid=2), simulating a file
    # where the user is listening to a non-default track, and rerun
    # detection -- it must follow the switch, not keep reporting the first
    # track's clap.
    mpv.aid = 2
    qapp.processEvents()
    time.sleep(0.2)
    switched_index = win._current_audio_stream_index()
    print(f"resolved ff-index after switching to aid=2: {switched_index}")
    assert switched_index == 2, f"expected ff-index 2 after switching tracks, got {switched_index}"

    win.source_panel.marker_strip.clear()
    win.detect_all_button.click()
    qapp.processEvents()
    ok = wait_for(lambda: win.detect_all_button.isEnabled(), qapp)
    assert ok, "detection did not finish in time"
    markers = win.source_panel.marker_strip.markers()
    print(f"markers with second track selected: {markers}")
    assert any(abs(m - 7.0) < 0.5 for m in markers), f"expected a marker near 7.0s (second track's clap) after switching: {markers}"
    assert not any(abs(m - 3.0) < 0.5 for m in markers), f"should not see the FIRST track's 3.0s clap after switching: {markers}"

    win.close()
    qapp.processEvents()
    print("\nPASS: clap detection follows mpv's actual selected audio track, not ffmpeg's default")


if __name__ == "__main__":
    main()