#!/usr/bin/env python
# -*- coding: utf-8 -*-

import os
import smtplib
import email
import logging
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication
from email.header import Header
from email.utils import formataddr, make_msgid, formatdate
from typing import Union, List, Dict, Any, Tuple
from pathlib import Path
from dotenv import load_dotenv

# 配置日志
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger('AliyunEmailSender')

# 加载环境变量
load_dotenv()


class EmailConfig:
    """邮件配置类，用于存储SMTP服务器相关配置"""
    
    def __init__(
        self,
        username: str | None = None,
        password: str | None = None,
        smtp_host: str = 'smtpdm.aliyun.com',
        smtp_port: int = 80,
        from_alias: str | None = None,
        reply_to: str | None = None,
        use_ssl: bool | None = None,
        debug_level: int = 0
    ) -> None:
        """
        初始化邮件配置
        
        Args:
            username: SMTP用户名
            password: SMTP密码
            smtp_host: SMTP服务器地址
            smtp_port: SMTP服务器端口
            from_alias: 发件人显示名称
            reply_to: 回复地址
            use_ssl: 是否使用SSL连接，若为None则根据端口自动判断
            debug_level: SMTP调试级别 (0-无调试, 1-调试)
        """
        self.username = username or os.getenv('MAIL_USERNAME')
        self.password = password or os.getenv('MAIL_PASSWORD')
        self.smtp_host = smtp_host or os.getenv('MAIL_SMTP_HOST', 'smtpdm.aliyun.com')
        
        # 处理端口号
        if smtp_port is not None:
            self.smtp_port = smtp_port
        else:
            env_port = os.getenv('MAIL_SMTP_PORT')
            self.smtp_port = int(env_port) if env_port else 80
            
        self.from_alias = from_alias or os.getenv('MAIL_FROM_ALIAS')
        self.reply_to = reply_to or os.getenv('MAIL_REPLY_TO')
        
        # 自动判断是否使用SSL
        if use_ssl is None:
            self.use_ssl = self.smtp_port == 465
        else:
            self.use_ssl = use_ssl
            
        self.debug_level = debug_level
        
        # 验证配置
        self.validate()
        
    def validate(self) -> None:
        """验证配置的有效性"""
        if not all([self.username, self.password]):
            raise ValueError("SMTP配置错误: 用户名和密码不能为空")
        
        if not self.smtp_host:
            raise ValueError("SMTP配置错误: SMTP服务器地址不能为空")


class EmailContent:
    """邮件内容类，用于构建邮件内容"""
    
    def __init__(
        self,
        subject: str,
        html_body: str | None = None,
        text_body: str | None = None,
        attachments: list[Union[str, Path, Tuple[str, bytes, str]]] | None = None
    ) -> None:
        """
        初始化邮件内容
        
        Args:
            subject: 邮件主题
            html_body: HTML格式的邮件内容
            text_body: 纯文本格式的邮件内容
            attachments: 附件列表，可以是文件路径、Path对象或(文件名,数据,MIME类型)元组
        """
        self.subject = subject
        self.html_body = html_body
        self.text_body = text_body
        self.attachments = attachments or []
        
        # 验证内容
        self.validate()
        
    def validate(self) -> None:
        """验证邮件内容的有效性"""
        if not self.html_body and not self.text_body:
            raise ValueError("邮件内容错误: HTML和纯文本内容不能同时为空")


class SMTPEmailSender:
    """阿里云SMTP邮件服务封装类"""
    
    def __init__(self, config: EmailConfig | None = None) -> None:
        """
        初始化邮件发送器
        
        Args:
            config: 邮件配置，如果为None则使用环境变量创建默认配置
        """
        self.config = config or EmailConfig()
    
    def create_message(
        self,
        content: EmailContent,
        to_addresses: Union[str, List[str]],
        cc_addresses: Union[str, List[str]] | None = None,
        bcc_addresses: Union[str, List[str]] | None = None,
        extra_headers: Dict[str, str] | None = None
    ) -> MIMEMultipart:
        """
        创建邮件消息对象
        
        Args:
            content: 邮件内容
            to_addresses: 收件人地址
            cc_addresses: 抄送地址
            bcc_addresses: 密送地址
            extra_headers: 额外的邮件头部
            
        Returns:
            MIMEMultipart: 创建的邮件对象
        """
        # 处理收件人列表
        to_list = to_addresses.split(',') if isinstance(to_addresses, str) else to_addresses
        cc_list = cc_addresses.split(',') if isinstance(cc_addresses, str) and cc_addresses else []
        bcc_list = bcc_addresses.split(',') if isinstance(bcc_addresses, str) and bcc_addresses else []
        
        # 创建复合邮件
        msg = MIMEMultipart('alternative')
        msg['Subject'] = Header(content.subject)
        msg['From'] = formataddr([self.config.from_alias, self.config.username]) if self.config.from_alias else self.config.username
        msg['To'] = ','.join(to_list)
        
        if cc_list:
            msg['Cc'] = ','.join(cc_list)
        
        if self.config.reply_to:
            msg['Reply-to'] = self.config.reply_to
            
        # 添加消息ID和日期
        msg['Message-id'] = make_msgid()
        msg['Date'] = formatdate()
        
        # 添加额外头部
        if extra_headers:
            for key, value in extra_headers.items():
                msg[key] = value
        
        # 添加邮件内容
        if content.text_body:
            text_part = MIMEText(content.text_body, _subtype='plain', _charset='UTF-8')
            msg.attach(text_part)
            
        if content.html_body:
            html_part = MIMEText(content.html_body, _subtype='html', _charset='UTF-8')
            msg.attach(html_part)
        
        # 添加附件
        for attachment in content.attachments:
            self._add_attachment(msg, attachment)
            
        return msg
    
    def _add_attachment(
        self, 
        msg: MIMEMultipart, 
        attachment: Union[str, Path, Tuple[str, bytes, str]]
    ) -> None:
        """
        添加附件到邮件
        
        Args:
            msg: 邮件对象
            attachment: 附件，可以是文件路径、Path对象或(文件名,数据,MIME类型)元组
        """
        try:
            if isinstance(attachment, (str, Path)):
                # 文件路径
                path = Path(attachment)
                filename = path.name
                
                with open(path, 'rb') as f:
                    data = f.read()
                
                mimetype = 'application/octet-stream'
            else:
                # (文件名,数据,MIME类型)元组
                filename, data, mimetype = attachment
                
            part = MIMEApplication(data, Name=filename)
            part['Content-Disposition'] = f'attachment; filename="{filename}"'
            part['Content-Type'] = f'{mimetype}; name="{filename}"'
            msg.attach(part)
            
        except Exception as e:
            logger.error(f"添加附件失败: {str(e)}")
    
    def send(
        self,
        content: EmailContent,
        to_addresses: Union[str, List[str]],
        cc_addresses: Union[str, List[str]] | None = None,
        bcc_addresses: Union[str, List[str]] | None = None,
        extra_headers: Dict[str, str] | None = None
    ) -> bool:
        """
        发送邮件
        
        Args:
            content: 邮件内容
            to_addresses: 收件人地址，可以是字符串(逗号分隔)或列表
            cc_addresses: 抄送地址，可以是字符串(逗号分隔)或列表(可选)
            bcc_addresses: 密送地址，可以是字符串(逗号分隔)或列表(可选)
            extra_headers: 额外的邮件头部(可选)
            
        Returns:
            bool: 发送是否成功
        """
        # 处理收件人列表
        to_list = to_addresses.split(',') if isinstance(to_addresses, str) else to_addresses
        cc_list = cc_addresses.split(',') if isinstance(cc_addresses, str) and cc_addresses else []
        bcc_list = bcc_addresses.split(',') if isinstance(bcc_addresses, str) and bcc_addresses else []
        
        # 所有接收方
        receivers = to_list + cc_list + bcc_list
        
        # 创建邮件
        msg = self.create_message(content, to_addresses, cc_addresses, bcc_addresses, extra_headers)
        
        # 发送邮件
        try:
            # 创建SMTP客户端
            if self.config.use_ssl:
                client = smtplib.SMTP_SSL(self.config.smtp_host, self.config.smtp_port)
            else:
                client = smtplib.SMTP(self.config.smtp_host, self.config.smtp_port)
            
            # 设置调试级别
            if self.config.debug_level > 0:
                client.set_debuglevel(self.config.debug_level)
                
            try:
                # 登录
                client.login(self.config.username, self.config.password)
                
                # 发送邮件
                client.sendmail(self.config.username, receivers, msg.as_string())
                logger.info(f"邮件已成功发送至 {len(receivers)} 个收件人")
                return True
                
            except smtplib.SMTPException as e:
                logger.error(f"SMTP错误: {str(e)}")
                return False
                
            finally:
                # 确保关闭连接
                client.quit()
                
        except Exception as e:
            logger.error(f"邮件发送失败: {str(e)}")
            return False
    
    def send_email(
        self, 
        to_addresses: Union[str, List[str]], 
        subject: str, 
        html_body: str | None = None, 
        text_body: str | None = None, 
        cc_addresses: Union[str, List[str]] | None = None, 
        bcc_addresses: Union[str, List[str]] | None = None,
        attachments: list[Union[str, Path, Tuple[str, bytes, str]]] | None = None,
        extra_headers: Dict[str, str] | None = None
    ) -> bool:
        """
        兼容旧版API的发送邮件方法
        
        Args:
            to_addresses: 收件人地址，可以是字符串(逗号分隔)或列表
            subject: 邮件主题
            html_body: HTML格式的邮件内容(可选，但html_body和text_body至少需要一个)
            text_body: 纯文本格式的邮件内容(可选，但html_body和text_body至少需要一个)
            cc_addresses: 抄送地址，可以是字符串(逗号分隔)或列表(可选)
            bcc_addresses: 密送地址，可以是字符串(逗号分隔)或列表(可选)
            attachments: 附件列表(可选)
            extra_headers: 额外的邮件头部(可选)
            
        Returns:
            bool: 发送是否成功
        """
        try:
            # 构建邮件内容
            content = EmailContent(
                subject=subject,
                html_body=html_body,
                text_body=text_body,
                attachments=attachments
            )
            
            # 发送邮件
            return self.send(
                content=content,
                to_addresses=to_addresses,
                cc_addresses=cc_addresses,
                bcc_addresses=bcc_addresses,
                extra_headers=extra_headers
            )
            
        except ValueError as e:
            logger.error(f"邮件参数错误: {str(e)}")
            return False
        except Exception as e:
            logger.error(f"邮件发送失败: {str(e)}")
            return False


def main() -> None:
    """示例用法"""
    try:
        # 初始化邮件发送器 - 使用环境变量
        email_sender = SMTPEmailSender()
        
        # 收件人列表
        recipients = "129xxx1@qq.com,sxxx@163.com"
        
        # 邮件内容
        subject = "测试邮件 - 阿里云SMTP邮件服务"
        html_content = """
        <html>
        <head>
            <style>
                body { font-family: Arial, sans-serif; }
                .container { padding: 20px; max-width: 600px; margin: 0 auto; }
                .header { color: #333; }
                .content { line-height: 1.6; }
                .footer { margin-top: 30px; font-size: 12px; color: #999; }
            </style>
        </head>
        <body>
            <div class="container">
                <h1 class="header">这是一封测试邮件</h1>
                <div class="content">
                    <p>这是通过阿里云SMTP邮件服务发送的测试邮件。</p>
                    <p>如果您收到这封邮件，说明邮件发送功能正常工作。</p>
                </div>
                <div class="footer">
                    此邮件为系统自动发送，请勿回复。
                </div>
            </div>
        </body>
        </html>
        """
        text_content = "这是一封测试邮件。这是通过阿里云SMTP邮件服务发送的测试邮件。如果您收到这封邮件，说明邮件发送功能正常工作。\n\n此邮件为系统自动发送，请勿回复。"
        
        # 1. 使用兼容旧版API发送
        logger.info("正在发送测试邮件(方法1)...")
        success = email_sender.send_email(
            to_addresses=recipients,
            subject=subject,
            html_body=html_content,
            text_body=text_content
        )
        
        if success:
            logger.info("邮件发送成功!")
        else:
            logger.error("邮件发送失败!")
            
        # 2. 使用新API发送（更灵活）
        logger.info("正在发送测试邮件(方法2)...")
        email_content = EmailContent(
            subject=subject,
            html_body=html_content,
            text_body=text_content
        )
        
        success = email_sender.send(
            content=email_content,
            to_addresses=recipients
        )
        
        if success:
            logger.info("邮件发送成功!")
        else:
            logger.error("邮件发送失败!")
        
    except Exception as e:
        logger.exception(f"发生异常: {str(e)}")
        
    # 示例：使用自定义配置
    try:
        # 自定义配置
        custom_config = EmailConfig(
            username="custom@example.com",
            password="password123",
            smtp_host="smtp.example.com",
            smtp_port=587,
            from_alias="自定义发件人",
            use_ssl=False
        )
        
        # 仅作示例，不实际发送
        logger.info("使用自定义配置创建发送器示例")
        _ = SMTPEmailSender(config=custom_config)
        
    except Exception as e:
        logger.exception(f"自定义配置示例异常: {str(e)}")


if __name__ == "__main__":
    main()