import re
from datetime import datetime
from typing import Dict, Tuple

# 你 COS 的公共前缀可以做成默认参数，便于不同环境覆盖
DEFAULT_COS_PREFIX = "https://data-miningc01-1318950322.cos.ap-shanghai-adc.myqcloud.com/"

def extract_datetime_from_filename(
    bag_filename: str,
    cos_prefix: str = DEFAULT_COS_PREFIX,
) -> Tuple[str, Dict[str, str]]:
    """
    从 .bag 文件名中提取采集时间，并生成对应的多视角视频 URL。

    期望文件名包含片段：_{YYYYMMDD}-{HHMMSS}_ 或以 .bag 结尾，例如：
        PL162802_event_all_time_event_20250416-193015_0.bag
        PL123456_event_all_time_event_20250828-221018.bag
        xx_20250524-180926_.bag
        xx_20250524-180926_3.bag

    返回:
        (datetime_full_str, video_urls)
        - datetime_full_str: 'YYYY-MM-DD HH:MM:SS'
        - video_urls: COS 上该 bag 的多视角视频 URL 字典

    异常:
        ValueError: 当文件名不匹配预期格式时抛出
    """
    # 提取日期时间
    match = re.search(r"_(\d{8})-(\d{6})(?:_|\.|$)", bag_filename)

    if not match:
        raise ValueError(f"文件名格式错误，无法提取时间信息：{bag_filename}")

    date_part, time_part = match.groups()
    year, month, day = date_part[:4], date_part[4:6], date_part[6:8]
    hour, minute, second = time_part[:2], time_part[2:4], time_part[4:6]

    datetime_full = f"{year}-{month}-{day} {hour}:{minute}:{second}"


    print(f'datetime_full:{datetime_full}')
    # 生成视频路径（与现有逻辑一致）
    # 去掉 .bag 后缀，再补上 " - {View}.mp4"
    base = bag_filename[:-4] if bag_filename.endswith(".bag") else bag_filename
    view_map = {
        "wide": "Wide",
        "left": "Left",
        "right": "Right",
        "rear_left": "Rear Left",
        "rear_right": "Rear Right",
        "rear": "Rear",
    }
    video_urls = {}
    for key, label in view_map.items():
        video_final_path = f"{base}- {label}.mp4"
        # 目录层级：momenta/videos/YYYY/MM/DD/{文件名 - {View}.mp4}
        video_key = f"momenta/videos/{year}/{month}/{day}/{video_final_path}"
        video_urls[key] = f"{cos_prefix}{video_key}"

    print(f'v{video_urls}')

    return datetime_full, video_urls