xiaoxia-saas/tests/unit/test_1970_atom_clip_service.py

"""#1970 素材原子化切片逻辑单元测试（纯函数，不依赖 DB）."""

from __future__ import annotations

import random

import pytest

from packages.domain.asset_atom_clip import AssetAtomClip
from packages.domain.atom_clip_service import (
    MAX_CLIP_SECONDS,
    MIN_CLIP_SECONDS,
    compute_atom_clips,
    compute_fallback_clips,
)


class TestComputeAtomClips:
    def test_short_asset_under_6s_single_clip(self):
        """<6 秒素材整条作为一个片段，不切。"""
        for dur in (0.1, 3.0, 5.99):
            clips = compute_atom_clips("a1", dur, rng=random.Random(1))
            assert len(clips) == 1
            assert clips[0].start_time == 0.0
            assert abs(clips[0].end_time - dur) < 0.01
            assert clips[0].clip_index == 0

    def test_exactly_6s_single_clip(self):
        clips = compute_atom_clips("a1", 6.0, rng=random.Random(1))
        assert len(clips) == 1
        assert clips[0].start_time == 0.0

    def test_zero_and_negative_duration_returns_empty(self):
        assert compute_atom_clips("a1", 0) == []
        assert compute_atom_clips("a1", -1.0) == []

    @pytest.mark.parametrize("seed", range(30))
    def test_clips_in_3_to_6_range(self, seed):
        """除末段外，每段时长在 3~6 秒；末段 >=3 秒。"""
        clips = compute_atom_clips("a1", 60.0, rng=random.Random(seed))
        assert len(clips) >= 2
        for clip in clips[:-1]:
            assert MIN_CLIP_SECONDS - 0.06 <= clip.duration <= MAX_CLIP_SECONDS + 0.06
        # 末段 >=3（不足 3 应已合并）
        assert clips[-1].duration >= MIN_CLIP_SECONDS - 0.06

    @pytest.mark.parametrize("dur", [6.01, 7.0, 9.0, 12.3, 30.0, 45.3, 100.0])
    def test_full_coverage_no_gaps_no_overlap(self, dur):
        clips = compute_atom_clips("a1", dur, rng=random.Random(int(dur * 100) % 10000))
        assert abs(clips[0].start_time) < 0.001
        assert abs(clips[-1].end_time - dur) < 0.01
        for prev, nxt in zip(clips, clips[1:], strict=False):
            assert abs(prev.end_time - nxt.start_time) < 0.001

    def test_clip_index_sequential(self):
        clips = compute_atom_clips("a1", 40.0, rng=random.Random(5))
        assert [c.clip_index for c in clips] == list(range(len(clips)))

    def test_tail_shorter_than_3s_merges_into_previous(self):
        """末段不足 3 秒必须合并到前一段。"""
        # 多跑种子，保证任何随机结果都不存在 <3s 的末段
        for seed in range(100):
            clips = compute_atom_clips("a1", 7.5, rng=random.Random(seed))
            assert clips[-1].duration >= MIN_CLIP_SECONDS - 0.06
            assert abs(clips[-1].end_time - 7.5) < 0.01

    def test_tail_between_3_and_6_stands_alone(self):
        """末段 >=3 秒独立成段。"""
        found_standalone = False
        for seed in range(100):
            clips = compute_atom_clips("a1", 9.5, rng=random.Random(seed))
            if len(clips) == 2:
                found_standalone = True
                assert clips[-1].duration >= MIN_CLIP_SECONDS - 0.06
        assert found_standalone, "9.5s 至少在某些种子下应切为两段"

    def test_scene_change_snap_within_window(self):
        """切点 0.5s 窗口内有切换点时，切点对齐到切换处。"""
        aligned = 0
        for seed in range(500):
            clips = compute_atom_clips("a1", 20.0, scene_change_points=[4.52], rng=random.Random(seed))
            if any(c.scene_change_at == 4.52 for c in clips):
                aligned += 1
                hit = next(c for c in clips if c.scene_change_at == 4.52)
                # 命中片段的右边界即切换点
                assert abs(hit.end_time - 4.52) < 0.001
        assert aligned > 0

    def test_scene_change_outside_window_not_force_aligned(self):
        """窗口外的切换点不应强行对齐。"""
        clips = compute_atom_clips("a1", 30.0, scene_change_points=[15.0], rng=random.Random(1))
        for c in clips:
            if c.scene_change_at is not None:
                assert abs(c.end_time - c.scene_change_at) < 0.001

    def test_scene_snap_never_creates_sub_3s_clip(self):
        """对齐不能导致片段短于 3 秒。"""
        for seed in range(100):
            clips = compute_atom_clips("a1", 40.0, scene_change_points=[3.2, 6.3, 9.4], rng=random.Random(seed))
            for c in clips:
                assert c.duration >= MIN_CLIP_SECONDS - 0.06

    def test_scene_points_out_of_duration_ignored(self):
        clips = compute_atom_clips("a1", 20.0, scene_change_points=[-1.0, 25.0, 4.0], rng=random.Random(3))
        assert all(c.scene_change_at != -1.0 and c.scene_change_at != 25.0 for c in clips)

    def test_tags_inherited(self):
        clips = compute_atom_clips("a1", 30.0, tags=["t1", "t2"], rng=random.Random(2))
        assert all(c.tags == ["t1", "t2"] for c in clips)

    def test_random_not_fixed_rhythm(self):
        """随机切片：不同种子产出的切点集合应不同（避免固定节奏）。"""
        cuts1 = [c.end_time for c in compute_atom_clips("a1", 60.0, rng=random.Random(1))]
        cuts2 = [c.end_time for c in compute_atom_clips("a1", 60.0, rng=random.Random(2))]
        assert cuts1 != cuts2

    def test_seed_reproducible(self):
        """相同种子结果可复现。"""
        a = [(c.start_time, c.end_time) for c in compute_atom_clips("a1", 60.0, rng=random.Random(42))]
        b = [(c.start_time, c.end_time) for c in compute_atom_clips("a1", 60.0, rng=random.Random(42))]
        assert a == b


class TestComputeFallbackClips:
    def test_fallback_marked_and_uniform(self):
        clips = compute_fallback_clips("a1", 20.0, clip_seconds=4.5)
        assert clips
        assert all(c.is_fallback for c in clips)
        for prev, nxt in zip(clips, clips[1:], strict=False):
            assert abs(prev.end_time - nxt.start_time) < 0.001
        assert abs(clips[-1].end_time - 20.0) < 0.01

    def test_fallback_tail_merge(self):
        """11.5s = 4.5+4.5+2.5 → 末段 2.5<3 合并 → 4.5+7.0。"""
        clips = compute_fallback_clips("a1", 11.5, clip_seconds=4.5)
        assert len(clips) == 2
        assert abs(clips[-1].duration - 7.0) < 0.01

    def test_fallback_short_asset(self):
        clips = compute_fallback_clips("a1", 2.0)
        assert len(clips) == 1
        assert clips[0].is_fallback

    def test_fallback_invalid_duration(self):
        assert compute_fallback_clips("a1", 0) == []
        assert compute_fallback_clips("a1", -5) == []

    def test_fallback_clip_has_no_persisted_id(self):
        clips = compute_fallback_clips("a1", 10.0)
        # 兜底片段仍有运行时 id（dataclass 生成），但 is_fallback 是判别标记
        assert all(isinstance(c, AssetAtomClip) for c in clips)