"""
缩略图生成器纯函数测试.

覆盖 _format_seek_time 等纯逻辑.
FFmpeg 抽帧与 OSS 上传由集成测试覆盖.
"""

from __future__ import annotations

import pytest
from video_processing.thumbnail_generator import _format_seek_time


class TestFormatSeekTime:
    """_format_seek_time 时间格式化."""

    def test_zero(self):
        assert _format_seek_time(0.0) == "00:00:00.00"

    def test_seconds_only(self):
        assert _format_seek_time(5.5) == "00:00:05.50"

    def test_minutes(self):
        assert _format_seek_time(65.25) == "00:01:05.25"

    def test_hours(self):
        assert _format_seek_time(3661.5) == "01:01:01.50"

    def test_exact_minute(self):
        assert _format_seek_time(60.0) == "00:01:00.00"

    def test_exact_hour(self):
        assert _format_seek_time(3600.0) == "01:00:00.00"

    def test_very_short(self):
        assert _format_seek_time(0.1) == "00:00:00.10"

    def test_long_video(self):
        # 超过1小时
        assert _format_seek_time(7200.0) == "02:00:00.00"

    def test_sub_second_precision(self):
        result = _format_seek_time(1.234)
        parts = result.split(":")
        assert len(parts) == 3
        sec_part = parts[2]
        assert "." in sec_part
        decimals = sec_part.split(".")[1]
        assert len(decimals) == 2

    def test_zero_padded_hours(self):
        # 小时始终是2位
        result = _format_seek_time(5.0)
        assert result.startswith("00:")

    def test_zero_padded_minutes(self):
        # 分钟始终是2位
        result = _format_seek_time(5.0)
        parts = result.split(":")
        assert len(parts[1]) == 2