"""Plain Python checks, including real FFmpeg encoding when installed."""
import binascii
import os
from pathlib import Path
import shutil
import struct
import sys
import tempfile
import unittest
import zlib

sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "Content/Python"))
from ue_workshop.paths import slug
from ue_workshop.video import encode


def png(path, rgb):
    def chunk(kind, data):
        return struct.pack(">I", len(data)) + kind + data + struct.pack(">I", binascii.crc32(kind + data) & 0xffffffff)
    path.write_bytes(b"\x89PNG\r\n\x1a\n" +
                     chunk(b"IHDR", struct.pack(">IIBBBBB", 4, 4, 8, 2, 0, 0, 0)) +
                     chunk(b"IDAT", zlib.compress((b"\x00" + bytes(rgb) * 4) * 4)) + chunk(b"IEND", b""))


class OfflineTests(unittest.TestCase):
    def test_generated_asset_name_cannot_escape_folder(self):
        for value in ["../Outside", "A/B", "", "A.B", "0Shot", "A B"]:
            with self.subTest(value=value), self.assertRaises(ValueError):
                slug(value)
        self.assertEqual(slug("MyShot_2"), "MyShot_2")

    def test_missing_frames_are_rejected_before_encoding(self):
        with tempfile.TemporaryDirectory() as directory:
            folder = Path(directory)
            png(folder / "frame_0001.png", (255, 0, 0))
            with self.assertRaisesRegex(RuntimeError, "numeracji"):
                encode(folder, 24)

    def test_incomplete_render_is_not_encoded(self):
        with tempfile.TemporaryDirectory() as directory:
            folder = Path(directory)
            png(folder / "frame_0000.png", (255, 0, 0))
            with self.assertRaisesRegex(RuntimeError, "zamiast 2"):
                encode(folder, 24, expected_frames=2)

    @unittest.skipUnless(shutil.which("ffmpeg") or os.environ.get("WORKSHOP_FFMPEG"), "FFmpeg missing")
    def test_real_mp4_encoding(self):
        with tempfile.TemporaryDirectory() as directory:
            folder = Path(directory) / "frames"
            folder.mkdir()
            png(folder / "frame_0000.png", (255, 0, 0))
            png(folder / "frame_0001.png", (0, 0, 255))
            movie = encode(folder, 24, expected_frames=2)
            self.assertGreater(movie.stat().st_size, 100)
            self.assertIn(b"ftyp", movie.read_bytes()[:32])


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