package org.oxerr.spring.security.wechat.web.authentication;
   
   import java.io.IOException;
   import java.io.InputStreamReader;
   import java.io.Reader;
   import java.nio.charset.StandardCharsets;
   
   import javax.servlet.ServletException;
   import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.oxerr.spring.security.wechat.core.WeChatMessageSource;
  import org.springframework.context.MessageSource;
  import org.springframework.context.MessageSourceAware;
  import org.springframework.context.support.MessageSourceAccessor;
  import org.springframework.util.FileCopyUtils;
  
  public abstract class AbstractJavaScriptRedirectWeChatService extends
  		AbstractSimpleRedirectWeChatService implements MessageSourceAware {
  
  	protected MessageSourceAccessor messages = WeChatMessageSource.getAccessor();
  	private final String template;
  
  	public AbstractJavaScriptRedirectWeChatService() {
  		try (Reader reader = new InputStreamReader(
  			AbstractJavaScriptRedirectWeChatService.class
  				.getResourceAsStream("loading.html"),
  			StandardCharsets.UTF_8)) {
  			template = FileCopyUtils.copyToString(reader);
  		} catch (IOException e) {
  			throw new RuntimeException(e);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public void setMessageSource(MessageSource messageSource) {
  		this.messages = new MessageSourceAccessor(messageSource);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public void redirectToAuthorize(HttpServletRequest request,
  			HttpServletResponse response) throws ServletException, IOException {
  		String redirectionPageHtml = generateRedirectionPageHtml(request, response);
  
  		response.setContentType("text/html;charset=UTF-8");
  		response.setContentLength(redirectionPageHtml.length());
  		response.getWriter().write(redirectionPageHtml);
  	}
  
  	private String generateRedirectionPageHtml(HttpServletRequest request,
  			HttpServletResponse response) throws ServletException, IOException {
  		String url = this.getAuthorizationURL(request, response);
  		String s = template.replaceFirst("#\\{loading\\}",
  			messages.getMessage(
  				"AbstractJavaScriptRedirectWeChatService.loading",
  				"Loading..."));
  		s = s.replaceFirst("\\$\\{url\\}", url);
  		return s;
  	}
  
  }