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

"""
邮件服务工具类，使用腾讯云SES服务发送邮件
"""

import logging
import random
import string
import json
import time
from typing import Dict, Any, Optional
import requests
from tencentcloud.common import credential
from tencentcloud.common.profile.client_profile import ClientProfile
from tencentcloud.common.profile.http_profile import HttpProfile
from tencentcloud.common.exception.tencent_cloud_sdk_exception import TencentCloudSDKException
from tencentcloud.ses.v20201002 import ses_client, models

from cryptoai.utils.config_loader import ConfigLoader

# 配置日志
logger = logging.getLogger('email_service')

# 验证码缓存，格式: {email: {'code': '123456', 'expire_time': timestamp}}
verification_codes = {}

class EmailService:
    """邮件服务类，用于发送验证码邮件"""
    
    def __init__(self):
        """初始化邮件服务"""
        # 加载腾讯云SES配置
        config_loader = ConfigLoader()
        self.ses_config = config_loader.get_ses_config()
        
        # 初始化SES客户端
        self.client = None
        self._init_client()
    
    def _init_client(self) -> None:
        """初始化腾讯云SES客户端"""
        try:
            # 创建认证对象
            cred = credential.Credential(
                self.ses_config.get('secret_id'),
                self.ses_config.get('secret_key')
            )
            
            # 创建HTTP配置
            http_profile = HttpProfile()
            http_profile.endpoint = "ses.tencentcloudapi.com"
            
            # 创建客户端配置
            client_profile = ClientProfile()
            client_profile.httpProfile = http_profile
            
            # 创建SES客户端
            self.client = ses_client.SesClient(cred, self.ses_config.get('region'), client_profile)
            
            logger.info("成功初始化腾讯云SES客户端")
            
        except TencentCloudSDKException as e:
            logger.error(f"初始化腾讯云SES客户端失败: {e}")
            self.client = None
    
    def generate_verification_code(self, length: int = 6) -> str:
        """
        生成数字验证码
        
        Args:
            length: 验证码长度，默认6位
            
        Returns:
            生成的验证码
        """
        return ''.join(random.choices(string.digits, k=length))
    
    def save_verification_code(self, email: str, code: str, expire_minutes: int = 10) -> None:
        """
        保存验证码到缓存
        
        Args:
            email: 邮箱地址
            code: 验证码
            expire_minutes: 过期时间（分钟），默认10分钟
        """
        expire_time = time.time() + expire_minutes * 60
        verification_codes[email] = {
            'code': code,
            'expire_time': expire_time
        }
    
    def verify_code(self, email: str, code: str) -> bool:
        """
        验证邮箱验证码
        
        Args:
            email: 邮箱地址
            code: 验证码
            
        Returns:
            验证是否成功
        """
        # 检查验证码是否存在
        if email not in verification_codes:
            return False
        
        # 获取验证码信息
        code_info = verification_codes[email]
        
        # 检查验证码是否过期
        if time.time() > code_info['expire_time']:
            # 删除过期验证码
            del verification_codes[email]
            return False
        
        # 验证验证码
        if code_info['code'] == code:
            # 验证成功后删除验证码
            del verification_codes[email]
            return True
        
        return False
    
    def send_verification_email(self, email: str) -> Dict[str, Any]:
        """
        发送验证码邮件
        
        Args:
            email: 收件人邮箱
            
        Returns:
            发送结果
        """
        if not self.client:
            try:
                self._init_client()
            except Exception as e:
                logger.error(f"重新初始化SES客户端失败: {e}")
                return {
                    'success': False,
                    'message': '邮件服务初始化失败'
                }
        
        try:
            # 生成验证码
            code = self.generate_verification_code()
            
            # 保存验证码
            self.save_verification_code(email, code)
            
            # 构建邮件内容
            subject = "CryptoAI - 您的验证码"
            html_content = f"""
            <html>
            <head>
                <style>
                    body {{ font-family: Arial, sans-serif; line-height: 1.6; }}
                    .container {{ max-width: 600px; margin: 0 auto; padding: 20px; }}
                    .header {{ background-color: #4A90E2; color: white; padding: 10px; text-align: center; }}
                    .content {{ padding: 20px; }}
                    .code {{ font-size: 24px; font-weight: bold; text-align: center; 
                             color: #4A90E2; padding: 10px; margin: 20px 0; }}
                    .footer {{ font-size: 12px; color: #999; text-align: center; margin-top: 30px; }}
                </style>
            </head>
            <body>
                <div class="container">
                    <div class="header">
                        <h2>CryptoAI 验证码</h2>
                    </div>
                    <div class="content">
                        <p>您好，</p>
                        <p>您正在注册 CryptoAI 账号，请使用以下验证码完成注册：</p>
                        <div class="code">{code}</div>
                        <p>验证码有效期为10分钟，请勿将验证码泄露给他人。</p>
                        <p>如果您没有进行此操作，请忽略此邮件。</p>
                    </div>
                    <div class="footer">
                        <p>此邮件由系统自动发送，请勿回复。</p>
                        <p>&copy; {time.strftime('%Y')} CryptoAI. 保留所有权利。</p>
                    </div>
                </div>
            </body>
            </html>
            """
            
            # 创建发送邮件请求
            req = models.SendEmailRequest()
            req.FromEmailAddress = self.ses_config.get('from_email')
            req.Destination = [email]
            req.Subject = subject
            req.Template = {
                "TemplateID": self.ses_config.get('template_id', 1),  # 使用默认模板ID或配置的模板ID
                "TemplateData": json.dumps({
                    "code": code
                })
            }
            
            # 如果没有配置模板ID，则使用HTML内容
            if not self.ses_config.get('template_id'):
                req.Template = None
                req.Simple = {
                    "Html": html_content
                }
            
            # 发送邮件
            resp = self.client.SendEmail(req)
            
            logger.info(f"成功发送验证码邮件到 {email}")
            
            return {
                'success': True,
                'message': '验证码已发送',
                'request_id': resp.RequestId
            }
            
        except TencentCloudSDKException as e:
            logger.error(f"发送验证码邮件失败: {e}")
            return {
                'success': False,
                'message': f'发送验证码失败: {e}'
            }
        except Exception as e:
            logger.error(f"发送验证码邮件出现未知错误: {e}")
            return {
                'success': False,
                'message': f'发送验证码失败: {str(e)}'
            }

# 单例模式
_email_service_instance = None

def get_email_service() -> EmailService:
    """
    获取邮件服务实例（单例模式）
    
    Returns:
        邮件服务实例
    """
    global _email_service_instance
    
    # 如果已经初始化过，直接返回
    if _email_service_instance is not None:
        return _email_service_instance
    
    # 创建实例
    _email_service_instance = EmailService()
    
    return _email_service_instance