# -*- coding: utf-8 -*-
"""字幕生成模块

根据每段文本的时长估算字幕时间轴，生成 SRT 文件。
"""

import os


def _fmt_time(seconds: float) -> str:
    """将秒数转换为 SRT 时间格式 HH:MM:SS,mmm"""
    ms = int((seconds - int(seconds)) * 1000)
    s = int(seconds) % 60
    m = int(seconds) // 60 % 60
    h = int(seconds) // 3600
    return f"{h:02d}:{m:02d}:{s:02d},{ms:03d}"


def build_srt(scenes: list, durations: list, out_path: str) -> str:
    """根据场景文本和每段时长生成 SRT 字幕。

    Args:
        scenes: [{"index":1,"text":"..."}, ...]
        durations: 每段音频时长（秒），与 scenes 一一对应
        out_path: 输出 .srt 路径

    Returns:
        str: 输出文件路径
    """
    os.makedirs(os.path.dirname(out_path), exist_ok=True)
    lines = []
    cursor = 0.0
    for i, (scene, dur) in enumerate(zip(scenes, durations), start=1):
        start = cursor
        end = cursor + dur
        lines.append(str(i))
        lines.append(f"{_fmt_time(start)} --> {_fmt_time(end)}")
        lines.append(scene["text"])
        lines.append("")
        cursor = end
    with open(out_path, "w", encoding="utf-8") as f:
        f.write("\n".join(lines))
    return out_path


if __name__ == "__main__":
    scenes = [{"index": 1, "text": "你好世界"}, {"index": 2, "text": "再见世界"}]
    print(build_srt(scenes, [2.0, 3.0], "output/subtitle/demo.srt"))