xiaoxia-saas/tests/unit/test_title_render_consistency.py

"""标题渲染前后端一致性测试。

验证 build_ass_content 生成的 ASS 样式参数与前端 drawTitleOnCanvas.ts 一致：
- 字号上限 36px
- 描边宽度 2px
- 阴影 blur=4, offset=2
- boolean stroke/shadow 自动转换
"""

import sys
from pathlib import Path

# Ensure packages is importable
sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "packages"))

from domain.ass_subtitle_builder import build_ass_content, build_ass_style


class TestFontSizeCap:
    """字号上限应与前端 Math.min(settings.size, 36) 一致。"""

    def test_default_font_size_is_36(self):
        """无 size 字段时，默认字号应为 36。"""
        config = {"text": "test"}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        assert ",36," in content, f"默认字号应为36，实际内容: {content}"

    def test_size_32_preserved(self):
        """size=32 应原样使用。"""
        config = {"size": 32}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        assert ",32," in content

    def test_size_60_capped_at_36(self):
        """size=60 应被 cap 到 36。"""
        config = {"size": 60}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        # 解析 Style 行的 Fontsize 字段（第3个字段，索引2）
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        font_size = int(fields[2])
        assert font_size == 36, f"字号60应被cap到36, 实际={font_size}"

    def test_size_24_preserved(self):
        """size=24 应原样使用（小于36，不cap）。"""
        config = {"size": 24}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        assert ",24," in content


class TestBooleanStrokeNormalization:
    """前端 stroke=true/false 应自动转换为标准 dict。"""

    def test_stroke_true_enables_outline(self):
        """stroke=true 应生成 outline_width=2 的样式。"""
        config = {"stroke": True}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        # 解析 Style 行的 Outline 字段（第17个字段，索引16）
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        outline_width = float(fields[16])
        assert outline_width == 2.0, f"stroke=true 应产生 outline_width=2, 实际={outline_width}"

    def test_stroke_false_no_outline(self):
        """stroke=false 应生成 outline_width=0 的样式。"""
        config = {"stroke": False}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        outline_width = float(fields[16])
        assert outline_width == 0.0, f"stroke=false 应产生 outline_width=0, 实际={outline_width}"

    def test_stroke_dict_still_works(self):
        """stroke={enabled:true, width:3} 仍应正常工作。"""
        config = {"stroke": {"enabled": True, "width": 3, "color": "#FF0000"}}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        outline_width = float(fields[16])
        assert outline_width == 3.0, f"自定义stroke width=3 应保留, 实际={outline_width}"


class TestBooleanShadowNormalization:
    """前端 shadow=true/false 应自动转换为标准 dict。"""

    def test_shadow_true_enables_shadow(self):
        """shadow=true 应生成 shadow_depth=2 的样式。"""
        config = {"shadow": True}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        # Shadow 字段是第18个（索引17）
        shadow_depth = int(fields[17])
        assert shadow_depth == 2, f"shadow=true 应产生 shadow_depth=2, 实际={shadow_depth}"

    def test_shadow_false_no_shadow(self):
        """shadow=false 应生成 shadow_depth=0 的样式。"""
        config = {"shadow": False}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        shadow_depth = int(fields[17])
        assert shadow_depth == 0, f"shadow=false 应产生 shadow_depth=0, 实际={shadow_depth}"

    def test_shadow_dict_still_works(self):
        """shadow={enabled:true, blur:8} 仍应正常工作。"""
        config = {"shadow": {"enabled": True, "blur": 8, "offset_x": 3, "offset_y": 3}}
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="测试标题",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]
        shadow_depth = int(fields[17])
        assert shadow_depth == 3, f"自定义shadow offset_y=3 应保留, 实际={shadow_depth}"


class TestFullStyleConsistency:
    """完整样式参数一致性测试。"""

    def test_frontend_default_style_matches_backend(self):
        """前端默认样式参数应在后端产生一致的 ASS 输出。

        前端默认：font_size=24(或用户设置), bold=false, stroke=true, shadow=true, color=#FFFFFF
        """
        config = {
            "text": "标题文本",
            "font": "思源黑体",
            "size": 28,
            "color": "#FFFFFF",
            "bold": True,
            "italic": False,
            "stroke": True,
            "shadow": True,
            "position": "top",
        }
        content = build_ass_content(
            video_width=1080,
            video_height=1920,
            video_duration=10.0,
            title_text="标题文本",
            title_config=config,
        )
        style_line = [l for l in content.splitlines() if l.startswith("Style: TitleStyle")][0]
        fields = [f.strip() for f in style_line.split(",")]

        # Fontname
        assert fields[1] == "思源黑体"
        # Fontsize = 28 (小于36，不cap)
        assert fields[2] == "28"
        # Bold = -1 (True)
        assert fields[7] == "-1"
        # Outline width = 2 (前端默认 stroke width)
        assert float(fields[16]) == 2.0
        # Shadow depth = 2 (offset_y)
        assert int(fields[17]) == 2
        # Alignment = 8 (top)
        assert int(fields[18]) == 8