package com.imyeyu.spring.annotation;

import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import jakarta.annotation.Nonnull;
import jakarta.servlet.http.HttpServletRequest;
import com.imyeyu.io.IO;
import com.imyeyu.java.bean.timi.TimiCode;
import com.imyeyu.java.bean.timi.TimiException;
import org.springframework.core.MethodParameter;
import org.springframework.stereotype.Component;
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;

@Component
public class RequestSingleParamResolver implements HandlerMethodArgumentResolver {

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

	@Override
	public Object resolveArgument(@Nonnull MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
		HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
        if (request == null) {
            throw new TimiException(TimiCode.REQUEST_BAD, "request illegal");
        }
        JsonElement element = JsonParser.parseString(IO.toString(request.getInputStream()));
        if (!element.isJsonObject()) {
            throw new TimiException(TimiCode.ARG_BAD, "not json object");
        }
        JsonObject object = element.getAsJsonObject();
		String parameterName = parameter.getParameterName();
		if (!object.has(parameterName)) {
            throw new TimiException(TimiCode.ARG_MISS, "not found " + parameterName + " param");
        }
		JsonElement el = object.get(parameterName);
		if (parameter.getParameterType().isAssignableFrom(Long.class)) {
			return el.getAsLong();
		}
		if (parameter.getParameterType().isAssignableFrom(Integer.class)) {
			return el.getAsInt();
		}
		if (parameter.getParameterType().isAssignableFrom(String.class)) {
			return el.getAsString();
		}
		throw new TimiException(TimiCode.ERROR, "not support parameter type");
	}
}