package at.gv.egiz.eaaf.core.impl.gui.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.ViewResolver;

import at.gv.egiz.eaaf.core.exceptions.GuiBuildException;
import at.gv.egiz.eaaf.core.impl.gui.utils.MvcGuiRenderUtils;
import lombok.extern.slf4j.Slf4j;

/**
 * Intercepter to render GUI in response processing.
 *
 * @author tlenz
 *
 */
@Slf4j
public class AsynchSpringMvcGuiBuilderIntercepter implements HandlerInterceptor {

  private @Autowired(required = false) ViewResolver[] viewResolvers;
  private @Autowired(required = false) LocaleResolver localeResolver;

  /*
   * (non-Javadoc)
   *
   * @see
   * org.springframework.web.servlet.HandlerInterceptor#postHandle(javax.servlet.
   * http. HttpServletRequest, javax.servlet.http.HttpServletResponse,
   * java.lang.Object, org.springframework.web.servlet.ModelAndView)
   */
  @Override
  public void postHandle(final HttpServletRequest httpReq, final HttpServletResponse httpResp,
      final Object handler, final ModelAndView modelAndView) throws Exception {

    final ModelAndView model = MvcGuiRenderUtils.getMvcForAsynchRendering(httpReq);
    if (model != null) {
      log.debug("Find GUI model: {} Starting model rendering ... ", model.getViewName());
      renderGui(model, httpReq, httpResp);

    } else {
      log.trace("No GUI model skipping asynch model rendering");

    }

  }

  private void renderGui(final ModelAndView mav,
      final HttpServletRequest httpReq, final HttpServletResponse httpResp) throws GuiBuildException {
    try {
      MvcGuiRenderUtils.render(mav, httpReq, httpResp, viewResolvers, localeResolver);

    } catch (final Exception e) {
      log.info("Can NOT generate GUI for illustration", e);
      throw new GuiBuildException(e.getMessage(), e);

    }
  }
}