from celery import shared_task
from loguru import logger
from django.core.mail import EmailMessage, EmailMultiAlternatives, EmailBackend
from django.utils import timezone
from datetime import timedelta
import traceback


@shared_task(bind=True, max_retries=3, default_retry_delay=60)
def celery_send_test_email(self, test_mode=True):
    """
    Celery异步发送测试邮件任务
    支持重试机制，适合生产环境使用
    """
    task_id = self.request.id if hasattr(self, 'request') else 'unknown'
    logger.info(f"[任务 {task_id}] 开始执行异步邮件发送任务")

    try:
        # 从数据库获取邮件配置
        from core.models import SystemConfig
        config = SystemConfig.get_config()
        # 优先使用sender_email，其次使用smtp_username作为发件人
        from_email = config.sender_email or config.smtp_username
        if not from_email:
            raise ValueError("未配置发件邮箱")

        # 验证发件人邮箱格式
        import re
        email_pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
        if not re.match(email_pattern, from_email):
            raise ValueError(f"发件人邮箱格式不正确: {from_email}")

        to_email = config.recipient_email or from_email
        # 验证收件人邮箱格式
        if not re.match(email_pattern, to_email):
            raise ValueError(f"收件人邮箱格式不正确: {to_email}")
        recipient_list = [to_email]

        # 获取SMTP配置
        host = config.smtp_server or 'localhost'
        port = config.smtp_port or 587
        username = config.smtp_username or ''
        password = config.smtp_password or ''
        use_tls = True  # 默认使用TLS

        # 创建邮件后端
        backend = EmailBackend(
            host=host,
            port=port,
            username=username,
            password=password,
            use_tls=use_tls,
            fail_silently=False
        )

        # 创建邮件内容
        subject = f"[Celery测试] 异步邮件发送成功 - {timezone.now().strftime('%Y-%m-%d %H:%M:%S')}"
        
        if test_mode:
            body = f"""
这是一封通过Celery异步发送的测试邮件。

✅ 邮件发送成功！

任务信息:
- 任务ID: {task_id}
- 发送时间: {timezone.now().strftime('%Y-%m-%d %H:%M:%S')}
- 发送方式: Celery异步任务
- 执行重试次数: {self.request.retries}

邮件配置:
- 发件服务器: {host}:{port}
- 使用TLS: {use_tls}

---
家庭日报系统
自动发送（Celery异步任务）
            """
        else:
            body = f"""
家庭日报系统测试邮件

发送时间: {timezone.now().strftime('%Y-%m-%d %H:%M:%S')}
发送方式: Celery异步任务
任务ID: {task_id}

这是一封测试邮件，用于验证Celery异步邮件发送功能。
            """

        # 创建邮件
        email = EmailMessage(
            subject=subject,
            body=body,
            from_email=from_email,
            to=recipient_list,
            connection=backend
        )
        email.content_subtype = 'plain'
        email.encoding = 'utf-8'

        # 发送邮件
        logger.info(f"[任务 {task_id}] 正在发送邮件...")
        sent_count = email.send(fail_silently=False)

        if sent_count > 0:
            logger.success(f"[任务 {task_id}] 邮件发送成功！发送给 {len(recipient_list)} 个收件人")
            return {
                'status': 'success',
                'task_id': task_id,
                'sent_to': len(recipient_list),
                'timestamp': timezone.now().isoformat()
            }
        else:
            raise Exception("邮件发送返回0，未能发送邮件")

    except Exception as e:
        error_msg = str(e)
        error_traceback = traceback.format_exc()
        
        logger.error(f"[任务 {task_id}] 邮件发送失败: {error_msg}")
        logger.error(f"[任务 {task_id}] 错误详情:\n{error_traceback}")

        # 检查是否应该重试
        if self.request.retries < self.max_retries:
            logger.info(f"[任务 {task_id}] 准备第 {self.request.retries + 1} 次重试...")
            # 重试延迟指数增长
            retry_delay = 60 * (2 ** self.request.retries)
            logger.info(f"[任务 {task_id}] {retry_delay}秒后进行重试")
            
            raise self.retry(exc=e, countdown=retry_delay)
        else:
            logger.error(f"[任务 {task_id}] 已达到最大重试次数 {self.max_retries}，放弃重试")
            
            # 返回错误信息而不是抛出异常
            return {
                'status': 'failed',
                'task_id': task_id,
                'error': error_msg,
                'retries': self.request.retries,
                'timestamp': timezone.now().isoformat()
            }


@shared_task(bind=True)
def celery_send_html_report_email(self, include_attachment=False):
    """
    Celery异步发送HTML报告邮件
    模拟每日报告发送功能
    """
    task_id = self.request.id if hasattr(self, 'request') else 'unknown'
    logger.info(f"[任务 {task_id}] 开始执行HTML报告邮件发送任务")

    try:
        # 从数据库获取邮件配置
        from core.models import SystemConfig
        config = SystemConfig.get_config()
        # 优先使用sender_email，其次使用smtp_username作为发件人
        from_email = config.sender_email or config.smtp_username
        if not from_email:
            raise ValueError("未配置发件邮箱")

        # 验证发件人邮箱格式
        import re
        email_pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
        if not re.match(email_pattern, from_email):
            raise ValueError(f"发件人邮箱格式不正确: {from_email}")

        to_email = config.recipient_email or from_email
        # 验证收件人邮箱格式
        if not re.match(email_pattern, to_email):
            raise ValueError(f"收件人邮箱格式不正确: {to_email}")
        if isinstance(to_email, list):
            recipient_list = to_email
        else:
            recipient_list = [to_email]

        # 获取SMTP配置
        host = config.smtp_server or 'localhost'
        port = config.smtp_port or 587
        username = config.smtp_username or ''
        password = config.smtp_password or ''
        use_tls = True  # 默认使用TLS

        # 准备报告数据
        today = timezone.now().date()
        yesterday = today - timedelta(days=1)

        report_data = {
            'today': today.strftime('%Y年%m月%d日'),
            'yesterday': yesterday.strftime('%Y年%m月%d日'),
            'tasks': [],
            'reading': {'count': 0, 'items': []},
            'insights': {'count': 0, 'items': []},
        }

        # 创建HTML邮件内容（使用普通字符串拼接，避免f-string中的%语法问题）
        html_content = '''
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <style>
        body { font-family: 'Microsoft YaHei', Arial, sans-serif; line-height: 1.6; color: #333; max-width: 600px; margin: 0 auto; }
        .header { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 30px 20px; text-align: center; }
        .header h1 { margin: 0; font-size: 24px; }
        .header .date { font-size: 14px; opacity: 0.9; margin-top: 10px; }
        .content { padding: 20px; background: #f9f9f9; }
        .section { background: white; border-radius: 8px; padding: 20px; margin-bottom: 20px; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
        .section h2 { color: #667eea; font-size: 18px; margin-top: 0; border-bottom: 2px solid #667eea; padding-bottom: 10px; }
        .stat { display: inline-block; background: #667eea; color: white; padding: 5px 15px; border-radius: 20px; margin: 5px; }
        .footer { text-align: center; padding: 20px; color: #666; font-size: 12px; }
        .success-badge { background: #28a745; color: white; padding: 10px 20px; border-radius: 5px; display: inline-block; }
    </style>
</head>
<body>
    <div class="header">
        <h1>📊 家庭日报</h1>
        <div class="date">{today}</div>
    </div>
    
    <div class="content">
        <div class="section">
            <h2>✅ 邮件发送测试</h2>
            <p>这是一封通过 <strong>Celery异步任务</strong> 发送的HTML格式邮件。</p>
            <p><strong>任务ID:</strong> {task_id}</p>
            <p><strong>发送时间:</strong> {send_time}</p>
            <p><strong>状态:</strong> <span class="success-badge">发送成功</span></p>
        </div>
        
        <div class="section">
            <h2>📈 统计信息</h2>
            <p>阅读记录: <span class="stat">{reading_count} 篇</span></p>
            <p>感悟记录: <span class="stat">{insights_count} 条</span></p>
            <p>家庭事项: <span class="stat">{tasks_count} 项</span></p>
        </div>
        
        <div class="section">
            <h2>📋 说明</h2>
            <p>此邮件由Celery异步任务自动发送。</p>
            <p>如需取消订阅，请联系系统管理员。</p>
        </div>
    </div>
    
    <div class="footer">
        <p>---</p>
        <p>家庭日报系统 | 自动发送</p>
        <p>任务ID: {task_id}</p>
    </div>
</body>
</html>
    '''.format(
        today=report_data['today'],
        task_id=task_id,
        send_time=timezone.now().strftime('%Y-%m-%d %H:%M:%S'),
        reading_count=report_data['reading']['count'],
        insights_count=report_data['insights']['count'],
        tasks_count=len(report_data['tasks'])
    )

        # 创建邮件后端
        backend = EmailBackend(
            host=host,
            port=port,
            username=username,
            password=password,
            use_tls=use_tls,
            fail_silently=False
        )

        # 创建邮件
        subject = f"[Celery] 家庭日报 {report_data['today']} - 测试报告"
        
        email = EmailMultiAlternatives(
            subject=subject,
            body=html_content,
            from_email=from_email,
            to=recipient_list,
            connection=backend
        )
        email.attach_alternative(html_content, "text/html")
        email.encoding = 'utf-8'

        # 添加附件（如果需要）
        if include_attachment:
            attachment_content = '''家庭日报测试报告
发送时间: {send_time}
任务ID: {task_id}
发送方式: Celery异步任务

这是一份自动生成的测试报告
            '''.format(
                send_time=timezone.now().isoformat(),
                task_id=task_id
            )
            email.attach('daily_report_test.txt', attachment_content, 'text/plain')
            logger.info(f"[任务 {task_id}] 已添加测试附件")

        # 发送邮件
        logger.info(f"[任务 {task_id}] 正在发送HTML报告邮件...")
        sent_count = email.send(fail_silently=False)

        if sent_count > 0:
            logger.success(f"[任务 {task_id}] HTML报告邮件发送成功！")
            return {
                'status': 'success',
                'task_id': task_id,
                'type': 'html_report',
                'sent_to': len(recipient_list),
                'has_attachment': include_attachment,
                'timestamp': timezone.now().isoformat()
            }
        else:
            raise Exception("邮件发送返回0")

    except Exception as e:
        error_msg = str(e)
        error_traceback = traceback.format_exc()
        
        logger.error(f"[任务 {task_id}] HTML报告邮件发送失败: {error_msg}")
        logger.error(f"[任务 {task_id}] 错误详情:\n{error_traceback}")
        
        return {
            'status': 'failed',
            'task_id': task_id,
            'type': 'html_report',
            'error': error_msg,
            'timestamp': timezone.now().isoformat()
        }