"""节奏模板单元测试（Issue #1764）。

覆盖：
- RHYTHM_TEMPLATES 池定义（8 种模板，#1764 原始 6 种 + #1768 新增 2 种）
- get_rhythm_template：根据 seed 选择模板
- adapt_template_length：适配不同片段数
- plan_clip_durations：按权重分配时长
- 时长约束：总时长 ≈ 配音时长，每段 >= 2s
"""

from __future__ import annotations

import pytest

from packages.domain.voice_duration_planner import (
    MIN_CLIP_DURATION,
    RHYTHM_TEMPLATES,
    adapt_template_length,
    get_rhythm_template,
    plan_clip_durations,
    total_output_duration,
)


class TestRhythmTemplates:
    """节奏模板池测试。"""

    def test_six_templates_defined(self):
        """预设 8 种节奏模板（#1764 原始 6 种 + #1768 新增 2 种）。"""
        assert len(RHYTHM_TEMPLATES) == 8

    def test_average_template_is_all_ones(self):
        """第一种模板是平均（全 1）。"""
        assert RHYTHM_TEMPLATES[0] == [1, 1, 1, 1, 1]

    def test_all_templates_have_5_elements(self):
        """所有模板长度为 5（会被 adapt 适配）。"""
        for tpl in RHYTHM_TEMPLATES:
            assert len(tpl) == 5


class TestGetRhythmTemplate:
    """get_rhythm_template 测试。"""

    def test_none_seed_returns_average(self):
        """None seed 返回平均模板。"""
        assert get_rhythm_template(None) == [1, 1, 1, 1, 1]

    def test_same_seed_same_template(self):
        """相同 seed 返回相同模板。"""
        tpl1 = get_rhythm_template(42)
        tpl2 = get_rhythm_template(42)
        assert tpl1 == tpl2

    def test_different_seeds_may_differ(self):
        """不同 seed 可能返回不同模板。"""
        templates_seen = set()
        for seed in range(100):
            tpl = tuple(get_rhythm_template(seed))
            templates_seen.add(tpl)
        # 100 个 seed 应该至少看到 3 种不同模板
        assert len(templates_seen) >= 3


class TestAdaptTemplateLength:
    """adapt_template_length 测试。"""

    def test_same_length(self):
        """片段数 == 模板长度时直接返回。"""
        tpl = [2, 1, 3, 1, 2]
        assert adapt_template_length(tpl, 5) == [2, 1, 3, 1, 2]

    def test_shorter_clip_count(self):
        """片段数 < 模板长度时截断。"""
        tpl = [2, 1, 3, 1, 2]
        assert adapt_template_length(tpl, 3) == [2, 1, 3]

    def test_longer_clip_count(self):
        """片段数 > 模板长度时循环填充。"""
        tpl = [2, 1, 3]
        result = adapt_template_length(tpl, 7)
        assert result == [2, 1, 3, 2, 1, 3, 2]

    def test_zero_clip_count(self):
        """片段数 0 返回空列表。"""
        assert adapt_template_length([1, 2, 3], 0) == []


class TestPlanClipDurationsWithRhythm:
    """plan_clip_durations 节奏模板测试。"""

    def test_average_template_equals_old_behavior(self):
        """全 1 模板 = 原来的平均分配。"""
        voice = 20.0
        clips = 4
        result = plan_clip_durations(clips, voice, rhythm_template=[1, 1, 1, 1])
        # 每段应该 ≈ 5s
        assert all(abs(d - 5.0) < 0.1 for d in result)
        assert abs(sum(result) - voice) < 0.1

    def test_weighted_template_different_durations(self):
        """权重模板产生不同时长的片段。"""
        voice = 18.0
        clips = 5
        # 权重 [2, 1, 3, 1, 2]：第 3 段最长，第 2/4 段最短
        template = [2, 1, 3, 1, 2]
        result = plan_clip_durations(clips, voice, rhythm_template=template)

        # 总时长 ≈ 配音时长
        assert abs(sum(result) - voice) < 0.5

        # 第 3 段应该最长
        assert result[2] > result[1]
        assert result[2] > result[3]

    def test_min_clip_duration_enforced(self):
        """每段 >= MIN_CLIP_DURATION (2s)。"""
        voice = 15.0
        clips = 5
        # 极端权重：某段权重极低
        template = [10, 1, 1, 1, 1]
        result = plan_clip_durations(clips, voice, rhythm_template=template)

        for d in result:
            assert d >= MIN_CLIP_DURATION

    def test_total_duration_with_transitions(self):
        """含转场时总时长仍然正确。"""
        voice = 20.0
        clips = 4
        effects = [None, "xfade", "fade", "cut"]
        durations = [0.0, 0.5, 0.3, 0.0]
        template = [2, 1, 1, 2]

        result = plan_clip_durations(
            clips,
            voice,
            transition_effects=effects,
            transition_durations=durations,
            rhythm_template=template,
        )

        # 成片净时长 = Σ段长 - Σ转场重叠 ≈ 配音时长
        output = total_output_duration(result, effects, durations)
        assert abs(output - voice) < 0.5

    def test_no_template_backward_compatible(self):
        """不传模板时行为与旧版一致（平均分配）。"""
        voice = 16.0
        clips = 4
        result = plan_clip_durations(clips, voice)
        assert all(abs(d - 4.0) < 0.1 for d in result)

    def test_six_templates_produce_different_structures(self):
        """6 种模板产生不同的时长结构。"""
        voice = 25.0
        clips = 5
        structures = set()

        for tpl in RHYTHM_TEMPLATES:
            result = plan_clip_durations(clips, voice, rhythm_template=tpl)
            # 用 round 后的元组作为结构指纹
            structure = tuple(round(d, 1) for d in result)
            structures.add(structure)

        # 至少 4 种不同结构
        assert len(structures) >= 4


class TestIssue1764Acceptance:
    """Issue #1764 验收测试。"""

    def test_batch_3_variants_at_least_2_different(self):
        """批量 3 个变体，至少 2 组不同片段时长序列。"""
        voice = 20.0
        clips = 5

        # 模拟 3 个变体用不同 seed
        seeds = [100, 200, 300]
        structures = []

        for seed in seeds:
            template = get_rhythm_template(seed)
            adapted = adapt_template_length(template, clips)
            durations = plan_clip_durations(clips, voice, rhythm_template=adapted)
            structures.append(tuple(round(d, 1) for d in durations))

        # 至少 2 种不同结构
        unique = len(set(structures))
        assert unique >= 2, f"Expected >= 2 unique structures, got {unique}: {structures}"