xiaoxia-saas/apps/worker/video_processing/render_subtitles.py

"""ASS 字幕生成模块 — 薄包装，实际逻辑在 packages/domain/ass_subtitle_builder.py.

职责：
- 将 title / subtitle 配置转换为 ASS 字幕文件
- 文件IO 在此模块，纯逻辑已抽离到 domain
- 供 UnifiedRenderService._maybe_generate_ass 调用
"""

from __future__ import annotations

import logging
from pathlib import Path
from typing import Any

from packages.domain.ass_subtitle_builder import (
    TITLE_MARGIN_BOTTOM,
    TITLE_MARGIN_SIDE,
    TITLE_MARGIN_TOP,
    build_ass_content,
)
from packages.domain.ass_subtitle_builder import build_ass_style as _build_ass_style_base  # noqa: F401 — 向后兼容
from packages.domain.ass_subtitle_builder import escape_ass_text as _escape_ass_text_base
from packages.domain.ass_subtitle_builder import format_ass_time as _format_ass_time_base
from packages.domain.ass_subtitle_builder import hex_to_ass_color as _hex_to_ass_color_base
from packages.domain.ass_subtitle_builder import position_to_ass_alignment as _position_to_ass_alignment_base

logger = logging.getLogger(__name__)


# 向后兼容：模块级函数保留为薄包装
def _hex_to_ass_color(hex_color: str) -> str:
    return _hex_to_ass_color_base(hex_color)


def _position_to_ass_alignment(position: str) -> int:
    return _position_to_ass_alignment_base(position)


def _build_ass_style(*args, **kwargs) -> str:
    return _build_ass_style_base(*args, **kwargs)


def _escape_ass_text(text: str) -> str:
    return _escape_ass_text_base(text)


def _format_ass_time(seconds: float) -> str:
    return _format_ass_time_base(seconds)


def generate_ass_subtitles(
    output_path: Path,
    *,
    video_width: int,
    video_height: int,
    video_duration: float,
    title_text: str = "",
    title_config: dict[str, Any] | None = None,
    subtitle_text: str = "",
    subtitle_config: dict[str, Any] | None = None,
) -> Path:
    """生成 ASS 字幕文件.

    Args:
        output_path: 输出 ASS 文件路径
        video_width: 视频宽度
        video_height: 视频高度
        video_duration: 视频总时长（秒）
        title_text: 标题文本
        title_config: 标题样式配置
        subtitle_text: 字幕文本
        subtitle_config: 字幕样式配置

    Returns:
        生成的 ASS 文件路径
    """
    content = build_ass_content(
        video_width=video_width,
        video_height=video_height,
        video_duration=video_duration,
        title_text=title_text,
        title_config=title_config,
        subtitle_text=subtitle_text,
        subtitle_config=subtitle_config,
    )

    output_path.parent.mkdir(parents=True, exist_ok=True)
    output_path.write_text(content, encoding="utf-8")
    return output_path