package cn.xluobo.config.security;

import org.springframework.security.access.AccessDecisionManager;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.stereotype.Service;

import java.util.Collection;
import java.util.Iterator;

/**
 * Created by zhangbaoyu on 18/1/9.
 */
//@Service
public class CustomAccessDecisionManager implements AccessDecisionManager {

    // decide 方法是判定是否拥有权限的决策方法，
    //authentication 是释CustomUserService中循环添加到 GrantedAuthority 对象中的权限信息集合.
    //object 包含客户端发起的请求的requset信息，可转换为 HttpServletRequest request = ((FilterInvocation) object).getHttpRequest();
    //configAttributes 为MyInvocationSecurityMetadataSource的getAttributes(Object object)这个方法返回的结果，此方法是为了判定用户请求的url 是否在权限表中，如果在权限表中，则返回给 decide 方法，用来判定用户是否有此权限。如果不在权限表中则放行。
    @Override
    public void decide(Authentication authentication, Object o, Collection<ConfigAttribute> configAttributes) throws AccessDeniedException, InsufficientAuthenticationException {
        if(null== configAttributes || configAttributes.size() <=0) {
            return;
        }
        ConfigAttribute c;
        String needRole;
        for(Iterator<ConfigAttribute> iter = configAttributes.iterator(); iter.hasNext(); ) {
            c = iter.next();
            needRole = c.getAttribute();
            for(GrantedAuthority ga : authentication.getAuthorities()) {//authentication 为在注释1 中循环添加到 GrantedAuthority 对象中的权限信息集合
                String authority = ga.getAuthority();
                if(needRole.trim().equals(authority)) {
                    return;
                }
            }
        }
        throw new AccessDeniedException("no right");
    }

    @Override
    public boolean supports(ConfigAttribute configAttribute) {
        return true;
    }

    @Override
    public boolean supports(Class<?> aClass) {
        return true;
    }
}
