package com.matrix.system.common.tag;


import com.matrix.system.common.authority.AuthorityManager;
import com.matrix.system.common.authority.DefaultAuthorityManager;
import com.matrix.system.common.constance.AppConstance;
import org.thymeleaf.IEngineConfiguration;
import org.thymeleaf.context.ITemplateContext;
import org.thymeleaf.engine.AttributeName;
import org.thymeleaf.model.IProcessableElementTag;
import org.thymeleaf.processor.element.AbstractAttributeTagProcessor;
import org.thymeleaf.processor.element.IElementTagStructureHandler;
import org.thymeleaf.standard.expression.IStandardExpression;
import org.thymeleaf.standard.expression.IStandardExpressionParser;
import org.thymeleaf.standard.expression.StandardExpressions;
import org.thymeleaf.templatemode.TemplateMode;

import com.matrix.core.tools.WebUtil;

/**
 * 页面按钮权限类
 * 
 * @author jiangyouyao
 * @email 512061637@qq.com
 * @date 2019年2月25日
 */
public class ButtonRoleAttributeTagProcessor extends AbstractAttributeTagProcessor {

	/**
	 * 标签名
	 */
	private static final String ATTR_NAME = "btn";

	/**
	 * 优先级
	 */
	private static final int PRECEDENCE = 10000;

	public ButtonRoleAttributeTagProcessor(final String dialectPrefix) {
		super( // This processor will apply only to HTML mode
				TemplateMode.HTML,
				// Prefix to be applied to name for matching
				dialectPrefix,
				// No tag name: match any tag name
				null,
				// No prefix to be applied to tag name
				false,
				// Name of the attribute that will be matched
				ATTR_NAME,
				// Apply dialect prefix to attribute name
				true,
				// Precedence (inside dialect's own precedence)
				PRECEDENCE,
				// Remove the matched attribute afterwards
				true);
	}

	/**
	 * 自定义标签主方法
	 * 
	 * @author jiangyouyao
	 * @email 512061637@qq.com
	 * @date 2019年1月12日
	 * @param context
	 * @param tag
	 * @param attributeName
	 * @param attributeValue
	 * @param structureHandler
	 */
	@Override
	protected void doProcess(ITemplateContext context, IProcessableElementTag tag, AttributeName attributeName,
			String attributeValue, IElementTagStructureHandler structureHandler) {
		final IEngineConfiguration configuration = context.getConfiguration();

		// Obtain the Thymeleaf Standard Expression parser
		final IStandardExpressionParser parser = StandardExpressions.getExpressionParser(configuration);

		// Parse the attribute value as a Thymeleaf Standard Expression
		final IStandardExpression expression = parser.parseExpression(context, attributeValue);

		// 标签的值 功能code-add 这种类型
		final String attrValue = expression.execute(context).toString();

		// 此时根据当前登录用户判断是否有该权限
		AuthorityManager authority = (DefaultAuthorityManager) WebUtil.getBean(AppConstance.DEFAULT_AUTHORITYMANAGER);

		if (!authority.isBtnPermitted(attrValue)) {
			// 如果没有该按钮权限，则直接移除该模块
			structureHandler.removeElement();
		}

	}

}