xiaoxia-saas/tests/unit/test_duration_compensation.py

"""Tests for duration compensation when source video is shorter than configured duration."""

from pathlib import Path

import pytest

from apps.worker.video_processing.unified_render_service import ResolvedClip, UnifiedRenderService


class TestClipEffectiveDurationWithSpeedCompensation:
    """Test _clip_effective_duration handles speed < 1 correctly."""

    def test_normal_speed_returns_min(self):
        """When speed=1.0, effective_duration = min(duration, actual_duration)."""
        clip = ResolvedClip(
            clip_id="c1",
            asset_id="a1",
            local_path=Path("/tmp/fake.mp4"),
            clip_type="main",
            order=0,
            start_time=0.0,
            duration=4.0,
            actual_duration=3.0,  # shorter than configured
            playback_speed=1.0,
        )
        # Without speed compensation, effective = min(4, 3) = 3
        assert UnifiedRenderService._clip_effective_duration(clip) == 3.0

    def test_compensated_speed_returns_configured_duration(self):
        """When speed < 1 (compensated), effective_duration = configured duration."""
        clip = ResolvedClip(
            clip_id="c1",
            asset_id="a1",
            local_path=Path("/tmp/fake.mp4"),
            clip_type="main",
            order=0,
            start_time=0.0,
            duration=4.0,
            actual_duration=3.0,  # shorter than configured
            playback_speed=0.75,  # compensated: 3/4 = 0.75
        )
        # With speed compensation, effective = configured duration = 4.0
        assert UnifiedRenderService._clip_effective_duration(clip) == 4.0

    def test_zero_actual_duration_returns_configured(self):
        """When actual_duration=0, effective_duration = configured duration."""
        clip = ResolvedClip(
            clip_id="c1",
            asset_id="a1",
            local_path=Path("/tmp/fake.mp4"),
            clip_type="main",
            order=0,
            start_time=0.0,
            duration=4.0,
            actual_duration=0.0,
            playback_speed=1.0,
        )
        assert UnifiedRenderService._clip_effective_duration(clip) == 4.0

    def test_compensated_speed_with_actual_zero(self):
        """When speed < 1 and actual=0, still returns configured duration."""
        clip = ResolvedClip(
            clip_id="c1",
            asset_id="a1",
            local_path=Path("/tmp/fake.mp4"),
            clip_type="main",
            order=0,
            start_time=0.0,
            duration=4.0,
            actual_duration=0.0,
            playback_speed=0.5,
        )
        assert UnifiedRenderService._clip_effective_duration(clip) == 4.0


class TestClipAdjustedDurationWithSpeedCompensation:
    """Test _clip_adjusted_duration accounts for compensated speed."""

    def test_adjusted_duration_with_compensation(self):
        """Adjusted duration = min(duration, actual) / speed.
        With compensation: min(4,3)/0.75 = 3/0.75 = 4.0
        This equals the configured duration, which is the goal.
        """
        clip = ResolvedClip(
            clip_id="c1",
            asset_id="a1",
            local_path=Path("/tmp/fake.mp4"),
            clip_type="main",
            order=0,
            start_time=0.0,
            duration=4.0,
            actual_duration=3.0,
            playback_speed=0.75,  # compensated
        )
        adjusted = UnifiedRenderService._clip_adjusted_duration(clip)
        # min(4,3)/0.75 = 3/0.75 = 4.0 (matches configured duration)
        assert abs(adjusted - 4.0) < 0.01