package com.mtons.mblog.shiro.tags;

import freemarker.core.Environment;
import freemarker.log.Logger;
import freemarker.template.TemplateDirectiveBody;
import freemarker.template.TemplateException;

import java.io.IOException;
import java.util.Map;

/**
 * Freemarker tag that renders the tag body if the current user known to the system, either from a successful login attempt
 * (not necessarily during the current session) or from 'RememberMe' services.
 * <p><b>Note:</b> This is <em>less</em> restrictive than the <code>AuthenticatedTag</code> since it only assumes
 * the user is who they say they are, either via a current session login <em>or</em> via Remember Me services, which
 * makes no guarantee the user is who they say they are.  The <code>AuthenticatedTag</code> however
 * guarantees that the current user has logged in <em>during their current session</em>, proving they really are
 * who they say they are.
 * </p>
 * <p>The logically opposite tag of this one is the {@link org.apache.shiro.web.tags.GuestTag}.
 * </p>
 * <p>Equivalent to {@link org.apache.shiro.web.tags.UserTag}</p>
 */
public class UserTag extends SecureTag {
    static final Logger log = Logger.getLogger("UserTag");

    @Override
    public void render(Environment env, Map params, TemplateDirectiveBody body) throws IOException, TemplateException {
        if (getSubject() != null && getSubject().getPrincipal() != null) {
            log.debug("Subject has known identity (aka 'principal'). Tag body will be evaluated.");
            renderBody(env, body);
        } else {
            log.debug("Subject does not exist or have a known identity (aka 'principal'). Tag body will not be evaluated.");
        }
    }
}