package com.ydtech.aop;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.ydtech.aop.request.RequestSingleParam;
import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;

public class RequestStringParamHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter methodParameter) {
        return methodParameter.hasParameterAnnotation(RequestSingleParam.class);
    }

    @Override
    public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
        RequestSingleParam requestSingleParam = methodParameter.getParameterAnnotation(RequestSingleParam.class);
        HttpServletRequest request = nativeWebRequest.getNativeRequest(HttpServletRequest.class);
        assert request != null;
        BufferedReader reader = request.getReader();
        StringBuilder sb = new StringBuilder();
        char[] buf = new char[1024];
        int rd;
        while ((rd = reader.read(buf)) != -1) {
            sb.append(buf, 0, rd);
        }

        String value = requestSingleParam.value();
        JSONObject jsonObject = JSON.parseObject(sb.toString());
        return jsonObject.get(value);
    }

}