package com.cloudroam.module.message;

import com.cloudroam.service.GroupService;
import com.cloudroam.service.UserService;
import com.auth0.jwt.exceptions.AlgorithmMismatchException;
import com.auth0.jwt.exceptions.InvalidClaimException;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.SignatureVerificationException;
import com.auth0.jwt.exceptions.TokenExpiredException;
import com.auth0.jwt.interfaces.Claim;
import io.github.talelin.core.token.DoubleJWT;
import com.cloudroam.model.UserDO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Map;

/**
 * @author 
 * @author 
 * websocket 拦截器，主要是jwt鉴权
 */
public class WebSocketInterceptor implements HandshakeInterceptor {
    @Autowired
    private DoubleJWT jwt;

    @Autowired
    private UserService userService;

    @Autowired
    private GroupService groupService;

    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler webSocketHandler, Map<String, Object> attributes) throws Exception {
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest httpServletRequest = (ServletServerHttpRequest) request;
            String tokenStr = httpServletRequest.getServletRequest().getParameter("token");
            if (tokenStr == null || tokenStr.isEmpty()) {
                writeMessageToBody(response, "authorization field is required");
                return false;
            }
            Map<String, Claim> claims;
            try {
                claims = jwt.decodeAccessToken(tokenStr);
            } catch (TokenExpiredException e) {
                writeMessageToBody(response, "token is expired");
                return false;
            } catch (AlgorithmMismatchException | SignatureVerificationException | JWTDecodeException | InvalidClaimException e) {
                writeMessageToBody(response, "token is invalid");
                return false;
            }
            if (claims == null) {
                writeMessageToBody(response, "token is invalid, can't be decode");
                return false;
            }
            int identity = claims.get("identity").asInt();
            UserDO user = userService.getById(identity);
            if (user == null) {
                writeMessageToBody(response, "user is not found");
                return false;
            }
            attributes.put(MessageConstant.USER_KEY, user);
            return true;
        }
        return false;
    }

    @Override
    public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) {
        // default implementation ignored
    }

    private boolean verifyAdmin(UserDO user) {
        return groupService.checkIsRootByUserId(user.getId());
    }

    private void writeMessageToBody(ServerHttpResponse response, String message) throws IOException {
        response.setStatusCode(HttpStatus.BAD_REQUEST);
        response.getBody().write(message.getBytes(StandardCharsets.UTF_8));
    }

}