package com.cm.common.utils;

import org.springframework.util.StringUtils;

import java.math.BigInteger;

/**
 * 权限计算帮助类
 *
 * @author WenG
 */
public class RightsHelper {
    /**
     * 利用BigInteger对权限进行2的权的和计算
     *
     * @param rights int型权限编码数组
     * @return 2的权的和
     */
    public static BigInteger sumRights(int[] rights) {
        BigInteger num = new BigInteger("0");
        for (int i = 0; i < rights.length; i++) {
            num = num.setBit(rights[i]);
        }
        return num;
    }

    /**
     * 利用BigInteger对权限进行2的权的和计算
     *
     * @param rights String型权限编码数组
     * @return 2的权的和
     */
    public static BigInteger sumRights(String[] rights) {
        BigInteger num = new BigInteger("0");
        for (int i = 0; i < rights.length; i++) {
            num = num.setBit(Integer.parseInt(rights[i]));
        }
        return num;
    }

    /**
     * 测试是否具有指定编码的权限
     *
     * @param sum
     * @param targetRights
     * @return
     */
    public static boolean testRights(BigInteger sum, int targetRights) {
        return sum.testBit(targetRights);
    }

    /**
     * 测试是否具有指定编码的权限
     *
     * @param sum
     * @param targetRights
     * @return
     */
    public static boolean testRights(String sum, int targetRights) {
        if (StringUtils.isEmpty(sum)) {
            return false;
        }
        return testRights(new BigInteger(sum), targetRights);
    }

    /**
     * 测试是否具有指定编码的权限
     *
     * @param sum
     * @param targetRights
     * @return
     */
    public static boolean testRights(String sum, String targetRights) {
        if (StringUtils.isEmpty(sum)) {
            return false;
        }
        return testRights(new BigInteger(sum), targetRights);
    }

    /**
     * 测试是否具有指定编码的权限
     *
     * @param sum
     * @param targetRights
     * @return
     */
    public static boolean testRights(BigInteger sum, String targetRights) {
        return testRights(sum, Integer.parseInt(targetRights));
    }

}