package com.example.demo.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.HashMap;
import java.util.Map;

/**
 * 腾讯云SES邮件推送回调控制器
 * 用于接收腾讯云SES服务的邮件事件推送
 * 
 * 支持的事件类型：
 * - 递送成功 (delivery)
 * - 腾讯云拒信 (reject)
 * - ESP退信 (bounce)
 * - 用户打开邮件 (open)
 * - 点击链接 (click)
 * - 退订 (unsubscribe)
 */
@RestController
@RequestMapping("/api/tencent/ses")
public class TencentSesWebhookController {

    private static final Logger logger = LoggerFactory.getLogger(TencentSesWebhookController.class);

    /**
     * 腾讯云SES邮件事件回调接口
     * 
     * 回调地址配置：
     * - 账户级回调：https://your-domain.com/api/tencent/ses/webhook
     * - 发信地址级回调：https://your-domain.com/api/tencent/ses/webhook
     * 
     * 支持端口：8080, 8081, 8082
     */
    @PostMapping("/webhook")
    public ResponseEntity<Map<String, Object>> handleSesWebhook(
            @RequestBody Map<String, Object> payload,
            @RequestHeader Map<String, String> headers) {
        
        logger.info("收到腾讯云SES回调: {}", payload);
        logger.info("请求头: {}", headers);
        
        try {
            // 验证签名（可选，建议在生产环境中启用）
            if (!verifySignature(payload, headers)) {
                logger.warn("签名验证失败");
                Map<String, Object> response = new HashMap<>();
                response.put("success", false);
                response.put("message", "签名验证失败");
                return ResponseEntity.badRequest().body(response);
            }
            
            // 解析回调数据
            String eventType = (String) payload.get("eventType");
            String messageId = (String) payload.get("messageId");
            String email = (String) payload.get("email");
            String timestamp = (String) payload.get("timestamp");
            
            logger.info("SES事件 - Type: {}, MessageId: {}, Email: {}, Timestamp: {}", 
                       eventType, messageId, email, timestamp);
            
            // 根据事件类型处理
            switch (eventType) {
                case "delivery":
                    handleDeliveryEvent(payload);
                    break;
                case "reject":
                    handleRejectEvent(payload);
                    break;
                case "bounce":
                    handleBounceEvent(payload);
                    break;
                case "open":
                    handleOpenEvent(payload);
                    break;
                case "click":
                    handleClickEvent(payload);
                    break;
                case "unsubscribe":
                    handleUnsubscribeEvent(payload);
                    break;
                default:
                    logger.warn("未知事件类型: {}", eventType);
                    handleUnknownEvent(payload);
            }
            
            Map<String, Object> response = new HashMap<>();
            response.put("success", true);
            response.put("message", "回调处理成功");
            response.put("timestamp", System.currentTimeMillis());
            
            return ResponseEntity.ok(response);
            
        } catch (Exception e) {
            logger.error("处理SES回调失败", e);
            Map<String, Object> response = new HashMap<>();
            response.put("success", false);
            response.put("message", "处理失败: " + e.getMessage());
            return ResponseEntity.badRequest().body(response);
        }
    }

    /**
     * 处理邮件递送成功事件
     */
    private void handleDeliveryEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String timestamp = (String) payload.get("timestamp");
        
        logger.info("邮件递送成功 - MessageId: {}, Email: {}, Timestamp: {}", 
                   messageId, email, timestamp);
        
        // 业务处理逻辑
        // 1. 更新数据库中的邮件状态
        // 2. 记录递送统计
        // 3. 更新用户活跃度
        // 4. 发送递送成功通知（如需要）
        
        // TODO: 实现具体的业务逻辑
        updateEmailDeliveryStatus(messageId, email, "delivered");
    }

    /**
     * 处理腾讯云拒信事件
     */
    private void handleRejectEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String reason = (String) payload.get("reason");
        String timestamp = (String) payload.get("timestamp");
        
        logger.warn("腾讯云拒信 - MessageId: {}, Email: {}, Reason: {}, Timestamp: {}", 
                   messageId, email, reason, timestamp);
        
        // 业务处理逻辑
        // 1. 记录拒信原因
        // 2. 检查邮件内容合规性
        // 3. 更新发送策略
        // 4. 通知管理员
        
        updateEmailDeliveryStatus(messageId, email, "rejected");
    }

    /**
     * 处理ESP退信事件
     */
    private void handleBounceEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String bounceType = (String) payload.get("bounceType");
        String bounceSubType = (String) payload.get("bounceSubType");
        String timestamp = (String) payload.get("timestamp");
        
        logger.warn("邮件退信 - MessageId: {}, Email: {}, BounceType: {}, BounceSubType: {}, Timestamp: {}", 
                   messageId, email, bounceType, bounceSubType, timestamp);
        
        // 业务处理逻辑
        // 1. 区分硬退信和软退信
        // 2. 硬退信：从邮件列表移除
        // 3. 软退信：稍后重试
        // 4. 更新邮箱有效性状态
        
        if ("Permanent".equals(bounceType)) {
            // 硬退信，移除邮箱
            removeInvalidEmail(email);
        } else {
            // 软退信，标记重试
            markEmailForRetry(messageId, email);
        }
        
        updateEmailDeliveryStatus(messageId, email, "bounced");
    }

    /**
     * 处理邮件打开事件
     */
    private void handleOpenEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String timestamp = (String) payload.get("timestamp");
        String userAgent = (String) payload.get("userAgent");
        String ipAddress = (String) payload.get("ipAddress");
        
        logger.info("邮件打开事件 - MessageId: {}, Email: {}, Timestamp: {}, UserAgent: {}, IpAddress: {}", 
                   messageId, email, timestamp, userAgent, ipAddress);
        
        // 业务处理逻辑
        // 1. 记录邮件打开统计
        // 2. 更新用户活跃度
        // 3. 分析用户行为
        // 4. 触发后续营销活动
        
        recordEmailOpen(messageId, email, timestamp, userAgent, ipAddress);
    }

    /**
     * 处理链接点击事件
     */
    private void handleClickEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String timestamp = (String) payload.get("timestamp");
        String link = (String) payload.get("link");
        String userAgent = (String) payload.get("userAgent");
        String ipAddress = (String) payload.get("ipAddress");
        
        logger.info("链接点击事件 - MessageId: {}, Email: {}, Timestamp: {}, Link: {}, UserAgent: {}, IpAddress: {}", 
                   messageId, email, timestamp, link, userAgent, ipAddress);
        
        // 业务处理逻辑
        // 1. 记录链接点击统计
        // 2. 分析用户兴趣
        // 3. 更新用户行为数据
        // 4. 触发转化跟踪
        
        recordLinkClick(messageId, email, timestamp, link, userAgent, ipAddress);
    }

    /**
     * 处理退订事件
     */
    private void handleUnsubscribeEvent(Map<String, Object> payload) {
        String messageId = (String) payload.get("messageId");
        String email = (String) payload.get("email");
        String timestamp = (String) payload.get("timestamp");
        String unsubscribeType = (String) payload.get("unsubscribeType");
        
        logger.info("用户退订 - MessageId: {}, Email: {}, Timestamp: {}, UnsubscribeType: {}", 
                   messageId, email, timestamp, unsubscribeType);
        
        // 业务处理逻辑
        // 1. 立即停止向该邮箱发送邮件
        // 2. 更新用户订阅状态
        // 3. 记录退订原因
        // 4. 发送退订确认邮件
        
        unsubscribeUser(email, unsubscribeType);
    }

    /**
     * 处理未知事件类型
     */
    private void handleUnknownEvent(Map<String, Object> payload) {
        logger.warn("收到未知事件类型: {}", payload);
        // 记录到数据库或日志文件，供后续分析
    }

    /**
     * 验证签名（简化版本）
     * 生产环境中应实现完整的签名验证逻辑
     */
    private boolean verifySignature(Map<String, Object> payload, Map<String, String> headers) {
        // TODO: 实现腾讯云SES签名验证
        // 1. 获取签名相关头部
        // 2. 验证时间戳
        // 3. 验证签名算法
        // 4. 验证Token
        
        String token = headers.get("X-Tencent-Token");
        String timestamp = headers.get("X-Tencent-Timestamp");
        String signature = headers.get("X-Tencent-Signature");
        
        // 简化验证：检查必要头部是否存在
        return token != null && timestamp != null && signature != null;
    }

    // ========== 业务方法实现 ==========

    private void updateEmailDeliveryStatus(String messageId, String email, String status) {
        // TODO: 更新数据库中的邮件状态
        logger.info("更新邮件状态 - MessageId: {}, Email: {}, Status: {}", messageId, email, status);
    }

    private void removeInvalidEmail(String email) {
        // TODO: 从邮件列表中移除无效邮箱
        logger.info("移除无效邮箱: {}", email);
    }

    private void markEmailForRetry(String messageId, String email) {
        // TODO: 标记邮件重试
        logger.info("标记邮件重试 - MessageId: {}, Email: {}", messageId, email);
    }

    private void recordEmailOpen(String messageId, String email, String timestamp, String userAgent, String ipAddress) {
        // TODO: 记录邮件打开统计
        logger.info("记录邮件打开 - MessageId: {}, Email: {}, Timestamp: {}", messageId, email, timestamp);
    }

    private void recordLinkClick(String messageId, String email, String timestamp, String link, String userAgent, String ipAddress) {
        // TODO: 记录链接点击统计
        logger.info("记录链接点击 - MessageId: {}, Email: {}, Link: {}", messageId, email, link);
    }

    private void unsubscribeUser(String email, String unsubscribeType) {
        // TODO: 处理用户退订
        logger.info("处理用户退订 - Email: {}, Type: {}", email, unsubscribeType);
    }
}
