import email
from email import policy
from email.parser import BytesParser
import os
import secrets

def generate_unique_id():
    # 获取当前时间的精确到秒的字符串表示
    current_time = datetime.now().strftime('%y%m%d%H%M%S')
    
    # 生成一个6位的随机数字字符串
    # 使用secrets.choice以获得更高的安全性
    random_part = ''.join(secrets.choice('0123456789') for _ in range(6))
    
    # 组合时间与随机数
    unique_id = f"{current_time}{random_part}"
    
    return unique_id

def download_attachments(eml_file_path,filenames,output_folder):
    # 读取.eml文件
    if os.path.exists(eml_file_path):
        with open(eml_file_path, 'rb') as file:
            msg = BytesParser(policy=policy.default).parse(file)

        # 遍历邮件的所有部分
        for part in msg.iter_parts():
            # 检查是否为附件
            if part.get_content_disposition() == 'attachment':
                filename = part.get_filename()
                print(f"filename{filename}")
                if filename:
                    # 解码文件名（如果需要）
                    dh = email.header.decode_header(filename)
                    if isinstance(dh[0][0], bytes):
                        filename = dh[0][0].decode(dh[0][1] 
                        if dh[0][1] 
                        else 'utf-8')
                    
                    # 创建附件保存路径
                    random_number = ''.generate_unique_id()+".pdf"
                    attachment_path = os.path.join(output_folder, random_number)
                    print(f"创建附件保存路径{attachment_path}")

                    
                    # 下载附件
                    with open(attachment_path, 'wb') as f:
                        f.write(part.get_payload(decode=True))
                    
                    print(f"附件已保存: {attachment_path}")

def batch_extract_eml_attachments(eml_folder, output_folder):
    """批量处理文件夹中的所有 .eml 文件"""
    print(output_folder)
    if not os.path.exists(output_folder):
        os.makedirs(output_folder)

    for filename in os.listdir(eml_folder):
        if filename.lower().endswith(".eml"):
            eml_path = os.path.join(eml_folder, filename)
            print(f"\n处理文件: {filename}")
            download_attachments(eml_path,filename,output_folder)


if __name__ == "__main__":
    # 配置路径
    eml_folder = "/media/ai/8E5C87DF5C87C087/4.30/1"      # 存放 .eml 文件的夹
    output_folder = "./attachments" # 附件输出目录

    # 执行批量提取
    batch_extract_eml_attachments(eml_folder, output_folder)
    print("\n所有附件提取完成！")