package com.ecep.contract.service;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;

import com.ecep.contract.handler.MessageNotitfication;
import com.ecep.contract.handler.WebSocketServerHandler;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * WebSocket消息服务
 * 提供向客户端发送WebSocket消息的功能
 */
@Service
public class WebSocketService {

    private static final Logger logger = Logger.getLogger(WebSocketService.class.getName());
    private final WebSocketServerHandler webSocketHandler;
    @Autowired
    private ObjectMapper objectMapper;

    public WebSocketService(WebSocketServerHandler webSocketHandler) {
        this.webSocketHandler = webSocketHandler;
    }

    /**
     * 向所有连接的客户端广播消息
     * 
     * @param message 要广播的消息内容
     */
    public void broadcastMessage(String message) {
        try {
            TextMessage textMessage = new TextMessage(message);
            webSocketHandler.broadcast(textMessage);
            logger.info("广播消息: " + message);
        } catch (Exception e) {
            logger.log(Level.SEVERE, "广播消息失败: " + e.getMessage(), e);
        }
    }

    /**
     * 向特定会话发送消息
     * 
     * @param session WebSocket会话
     * @param message 要发送的消息内容
     */
    public void sendMessage(WebSocketSession session, String message) {
        try {
            if (session != null && session.isOpen()) {
                session.sendMessage(new TextMessage(message));
                logger.info("向会话发送消息: " + session.getId() + ", 消息: " + message);
            }
        } catch (IOException e) {
            logger.log(Level.SEVERE, "向会话发送消息失败: " + session.getId() + ", 原因: " + e.getMessage(), e);
        }
    }

    /**
     * 获取当前活跃的WebSocket会话数量
     * 
     * @return 活跃会话数
     */
    public int getActiveSessionCount() {
        return webSocketHandler.getActiveSessionCount();
    }

    /**
     * 发送系统通知
     * 
     * @param notification 通知内容
     */
    public void sendSystemNotification(String notification) {
        MessageNotitfication messageNotitfication = new MessageNotitfication();
        messageNotitfication.setType("notification");
        messageNotitfication.setContent(notification);
        try {
            String jsonMessage = objectMapper.writeValueAsString(messageNotitfication);
            broadcastMessage(jsonMessage);
        } catch (Exception e) {
            logger.log(Level.SEVERE, "发送系统通知失败: " + e.getMessage(), e);
        }
    }

    /**
     * 发送业务数据更新通知
     * 
     * @param dataType  数据类型
     * @param operation 操作类型（create, update, delete）
     * @param id        数据ID
     */
    public void sendDataUpdate(String dataType, String operation, String id) {
        String message = String.format(
                "{\"type\":\"data_update\",\"dataType\":\"%s\",\"operation\":\"%s\",\"id\":\"%s\"}",
                escapeJson(dataType),
                escapeJson(operation),
                escapeJson(id));
        broadcastMessage(message);
    }

    /**
     * 转义JSON字符串中的特殊字符
     * 
     * @param text 要转义的文本
     * @return 转义后的文本
     */
    private String escapeJson(String text) {
        if (text == null) {
            return "";
        }
        return text
                .replace("\\", "\\\\")
                .replace("\"", "\\\"")
                .replace("\b", "\\b")
                .replace("\f", "\\f")
                .replace("\n", "\\n")
                .replace("\r", "\\r")
                .replace("\t", "\\t");
    }
}