"""Tests for audio helpers: speed parameters, chunk cleanup, and encoding."""

import tempfile
import unittest
from pathlib import Path

from converter import config
from converter.audio import _encode_args, build_ffmetadata, cleanup_chunks, speed_export_params


class SpeedExportParamsTests(unittest.TestCase):
    def test_normal_speed_no_filter(self):
        self.assertEqual(speed_export_params(1.0), [])

    def test_simple_speedup(self):
        self.assertEqual(speed_export_params(1.5), ["-filter:a", "atempo=1.5"])

    def test_simple_slowdown(self):
        self.assertEqual(speed_export_params(0.75), ["-filter:a", "atempo=0.75"])

    def test_chained_speedup_beyond_2x(self):
        self.assertEqual(speed_export_params(3.0), ["-filter:a", "atempo=2.0,atempo=1.5"])

    def test_chained_slowdown_below_half(self):
        self.assertEqual(speed_export_params(0.25), ["-filter:a", "atempo=0.5,atempo=0.5"])

    def test_zero_speed_rejected(self):
        with self.assertRaises(ValueError):
            speed_export_params(0)

    def test_negative_speed_rejected(self):
        with self.assertRaises(ValueError):
            speed_export_params(-1.5)


class CleanupChunksTests(unittest.TestCase):
    def test_removes_only_chunk_files(self):
        with tempfile.TemporaryDirectory() as tmp:
            chunks_dir = Path(tmp)
            (chunks_dir / "chunk_0001.wav").write_bytes(b"stale")
            (chunks_dir / "chunk_0002.wav").write_bytes(b"stale")
            (chunks_dir / "keep.txt").write_bytes(b"keep")

            original = config.CHUNKS_FOLDER
            config.CHUNKS_FOLDER = chunks_dir
            try:
                cleanup_chunks()
            finally:
                config.CHUNKS_FOLDER = original

            self.assertFalse((chunks_dir / "chunk_0001.wav").exists())
            self.assertFalse((chunks_dir / "chunk_0002.wav").exists())
            self.assertTrue((chunks_dir / "keep.txt").exists())

    def test_removes_chapter_files(self):
        with tempfile.TemporaryDirectory() as tmp:
            chunks_dir = Path(tmp)
            (chunks_dir / "chapter_0001.m4b").write_bytes(b"stale")
            (chunks_dir / "chunk_0001.wav").write_bytes(b"stale")

            original = config.CHUNKS_FOLDER
            config.CHUNKS_FOLDER = chunks_dir
            try:
                cleanup_chunks()
            finally:
                config.CHUNKS_FOLDER = original

            self.assertFalse((chunks_dir / "chapter_0001.m4b").exists())
            self.assertFalse((chunks_dir / "chunk_0001.wav").exists())


class EncodeArgsTests(unittest.TestCase):
    def test_mp3_uses_bitrate_only(self):
        self.assertEqual(_encode_args("mp3"), ["-b:a", config.AUDIO_BITRATE])

    def test_m4b_uses_aac(self):
        self.assertEqual(_encode_args("m4b"), ["-c:a", "aac", "-b:a", config.AUDIO_BITRATE])


class BuildFFMetadataTests(unittest.TestCase):
    def test_writes_chapters(self):
        chapters = [(0, 1200, "One"), (1200, 2500, "Two")]
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "meta.txt"
            build_ffmetadata(chapters, path)
            content = path.read_text(encoding="utf-8")

        self.assertTrue(content.startswith(";FFMETADATA1\n"))
        self.assertIn("[CHAPTER]", content)
        self.assertIn("TIMEBASE=1/1000", content)
        self.assertIn("START=0", content)
        self.assertIn("END=1200", content)
        self.assertIn("title=One", content)
        self.assertIn("START=1200", content)
        self.assertIn("title=Two", content)


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