import json
import shutil
import subprocess
from pathlib import Path

import pytest

from spelunkai_recording.frames import FrameExtractionResult, extract_frames
from spelunkai_recording.session import session_paths

FFMPEG_AVAILABLE = shutil.which("ffmpeg") is not None


def test_is_in_sync_true_when_counts_match():
    result = FrameExtractionResult(
        frames_dir=Path("."), extracted_frame_count=3, manifest_frame_count=3, input_log_line_count=3,
    )
    assert result.is_in_sync


def test_is_in_sync_false_when_counts_differ():
    result = FrameExtractionResult(
        frames_dir=Path("."), extracted_frame_count=3, manifest_frame_count=3, input_log_line_count=2,
    )
    assert not result.is_in_sync


@pytest.mark.skipif(not FFMPEG_AVAILABLE, reason="ffmpeg not installed")
def test_extract_frames_matches_synthetic_video(tmp_path: Path):
    paths = session_paths(tmp_path, "synthetic")
    frame_count = 5

    subprocess.run(
        [
            "ffmpeg", "-y",
            "-f", "lavfi", "-i", "testsrc=size=64x64:rate=10",
            "-frames:v", str(frame_count),
            "-c:v", "libx264rgb", "-qp", "0",
            str(paths.video),
        ],
        check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
    )

    paths.manifest.write_text(
        json.dumps({
            "started_at": "2026-01-01T00:00:00+00:00",
            "video_file": paths.video.name,
            "input_log_file": paths.input_log.name,
            "fps": 10,
            "width": 64,
            "height": 64,
            "frame_count": frame_count,
        }),
        encoding="utf-8",
    )

    with paths.input_log.open("w", encoding="utf-8") as f:
        for i in range(frame_count):
            f.write(json.dumps({"frame": i, "t": i / 10, "keys": []}) + "\n")

    frames_dir = tmp_path / "synthetic_frames"
    result = extract_frames(paths, frames_dir)

    assert result.is_in_sync
    assert result.extracted_frame_count == frame_count
    assert (frames_dir / "frame_000000.png").exists()
    assert (frames_dir / f"frame_{frame_count - 1:06d}.png").exists()