package com.github.tangyi.gateway.filters;

import cn.hutool.core.util.StrUtil;
import com.github.tangyi.common.core.constant.CommonConstant;
import com.github.tangyi.common.core.properties.SysProperties;
import com.github.tangyi.common.core.utils.SysUtil;
import com.github.tangyi.gateway.constants.GatewayConstant;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.util.UriComponentsBuilder;
import reactor.core.publisher.Mono;

import java.net.URI;

/**
 * 解密过滤器
 * 对外密码字段的名称是credential，在这里解密，转换成password
 *
 * @author tangyi
 * @date 2019/3/18 11:30
 */
@Slf4j
@AllArgsConstructor
@Configuration
@ConditionalOnProperty(value = "sys.key")
public class DecodePasswordFilter implements GlobalFilter, Ordered {

    private static final String CREDENTIAL = "credential";

    private static final String PASSWORD = "password";

    private final SysProperties sysProperties;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 当前请求
        ServerHttpRequest request = exchange.getRequest();
        // 请求的URI
        URI uri = request.getURI();
        // 获取token的请求
        if (HttpMethod.POST.matches(request.getMethodValue()) && StrUtil.containsAnyIgnoreCase(uri.getPath(), GatewayConstant.OAUTH_TOKEN_URL, GatewayConstant.REGISTER,
                GatewayConstant.MOBILE_TOKEN_URL)) {
            String grantType = request.getQueryParams().getFirst(GatewayConstant.GRANT_TYPE);
            // 授权类型为密码模式则解密
            if (CommonConstant.GRANT_TYPE_PASSWORD.equals(grantType) || StrUtil.containsAnyIgnoreCase(uri.getPath(), GatewayConstant.REGISTER)) {
                String credential = request.getQueryParams().getFirst(CREDENTIAL);
                if (StringUtils.isNotBlank(credential)) {
                    try {
                        // 开始解密
                        credential = SysUtil.decryptAES(credential, sysProperties.getKey());
                        credential = credential.trim();
                    } catch (Exception e) {
                        log.error("credential decrypt fail:{}", credential);
                    }
                    URI newUri = UriComponentsBuilder.fromUri(uri)
                            // 替换password字段
                            .replaceQueryParam(PASSWORD, credential)
                            // 替换credential字段
                            .replaceQueryParam(CREDENTIAL, credential)
                            .build(true).toUri();
                    request = request.mutate().uri(newUri).build();
                    return chain.filter(exchange.mutate().request(request).build());
                }
            }
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return -100;
    }
}
