package cn.flightfeather.supervision.socket;

import cn.flightfeather.supervision.common.utils.JsonUtil;
import org.springframework.util.StringUtils;

public class WebSocketMessageParser {
    private static final String START_STR = "##";
    private static final String SPLIT_STR = "&&";
    private static final String END_STR = "%%";

    /**
     * 消息格式校验
     * @param message 消息
     * @return 格式是否合规
     */
    private static boolean verificationMessage(String message) {
        if (StringUtils.isEmpty(message)) {
            return false;
        }
        if (!message.startsWith(START_STR)) {
            return false;
        }
        if (!message.endsWith(END_STR)) {
            return false;
        }
        return true;
    }
    /**
     * 解析出类型和内容
     * @param message socket消息中的data字段
     * @return 解析结果，如果格式不正确则返回null
     */
    public static WebSocketMessage decodeMessage(String message) {
        if (!verificationMessage(message)) {
            // 发挥一个不会被处理的消息
            return new WebSocketMessage(-1, "");
        }
        WebSocketMessage webSocketMessage = new WebSocketMessage();
        String[] parts = message.substring(START_STR.length(), message.length() - END_STR.length()).split(SPLIT_STR);
        webSocketMessage.setType(Integer.parseInt(parts[0]));
        webSocketMessage.setContent(JsonUtil.INSTANCE.getGson().fromJson(parts[1], Object.class));
        return webSocketMessage;
    }
    /**
     * 生成指定格式的消息字符串
     * @return 生成的消息字符串
     */
    public static String encodeMessage(WebSocketMessage webSocketMessage) {
        return START_STR + webSocketMessage.getType() + SPLIT_STR + JsonUtil.INSTANCE.getGson().toJson(webSocketMessage.getContent(), webSocketMessage.getContent().getClass()) + END_STR;
    }
}