package com.ruoyi.websocket.config;

import java.util.Collections;
import java.util.Enumeration;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;
import com.ruoyi.common.constant.Constants;
import com.ruoyi.common.core.domain.model.LoginUser;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.framework.web.service.TokenService;

/**
 * WebSocket 握手拦截器：校验 JWT Token（支持 query 参数 token 或 Authorization header）
 *
 * @author ruoyi
 */
@Component
public class WebSocketHandshakeHandler implements HandshakeInterceptor {

    private final TokenService tokenService;

    public WebSocketHandshakeHandler(TokenService tokenService) {
        this.tokenService = tokenService;
    }

    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response,
                                  WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
        if (!(request instanceof ServletServerHttpRequest)) {
            return false;
        }
        ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
        HttpServletRequest req = servletRequest.getServletRequest();
        String token = req.getParameter("token");
        if (StringUtils.isEmpty(token)) {
            String auth = req.getHeader("Authorization");
            if (StringUtils.isNotEmpty(auth) && auth.startsWith(Constants.TOKEN_PREFIX)) {
                token = auth.substring(Constants.TOKEN_PREFIX.length()).trim();
            }
        }
        if (StringUtils.isEmpty(token)) {
            return false;
        }
        final String tokenFinal = token;
        HttpServletRequest wrappedReq = new HttpServletRequestWrapper(req) {
            @Override
            public String getHeader(String name) {
                if ("Authorization".equalsIgnoreCase(name)) {
                    return Constants.TOKEN_PREFIX + tokenFinal;
                }
                return super.getHeader(name);
            }
            @Override
            public Enumeration<String> getHeaders(String name) {
                if ("Authorization".equalsIgnoreCase(name)) {
                    return Collections.enumeration(Collections.singletonList(Constants.TOKEN_PREFIX + tokenFinal));
                }
                return super.getHeaders(name);
            }
        };
        LoginUser loginUser = tokenService.getLoginUser(wrappedReq);
        if (loginUser == null) {
            return false;
        }
        attributes.put("loginUser", loginUser);
        return true;
    }

    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response,
                               WebSocketHandler wsHandler, Exception exception) {
    }
}