package com.ruoyi.gateway.filter;

import java.nio.charset.StandardCharsets;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONObject;
import com.ruoyi.common.core.utils.ServletUtils;
import com.ruoyi.common.core.utils.StringUtils;
import com.ruoyi.gateway.config.properties.CaptchaProperties;
import com.ruoyi.gateway.service.ValidateCodeService;

import reactor.core.publisher.Flux;

/**
 * 验证码过滤器
 *
 * @author ruoyi
 */
@Component
public class ValidateCodeFilter extends AbstractGatewayFilterFactory<Object> {
    private static final String[] VALIDATE_URL = new String[] { "/auth/login", "/auth/register" };
    private static final String CODE = "code";
    private static final String UUID = "uuid";

    @Autowired
    private ValidateCodeService validateCodeService;

    @Autowired
    private CaptchaProperties captchaProperties;

    @Override
    public GatewayFilter apply(Object config) {
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            if (!StringUtils.containsAnyIgnoreCase(request.getURI().getPath(), VALIDATE_URL)
                    || !captchaProperties.getEnabled()) {
                return chain.filter(exchange);
            }

            return DataBufferUtils.join(request.getBody()).flatMap(dataBuffer -> {
                byte[] body = new byte[dataBuffer.readableByteCount()];
                dataBuffer.read(body);
                DataBufferUtils.release(dataBuffer);

                try {
                    JSONObject json = JSON.parseObject(new String(body, StandardCharsets.UTF_8));
                    validateCodeService.checkCaptcha(json.getString(CODE), json.getString(UUID));
                } catch (Exception e) {
                    return ServletUtils.webFluxResponseWriter(exchange.getResponse(), e.getMessage());
                }

                ServerHttpRequest decoratedRequest = new ServerHttpRequestDecorator(request) {
                    @Override
                    public Flux<DataBuffer> getBody() {
                        return Flux.just(exchange.getResponse().bufferFactory().wrap(body));
                    }
                };
                return chain.filter(exchange.mutate().request(decoratedRequest).build());
            });
        };
    }
}