SpringCloudBase/zen-api/src/main/kotlin/com/gxzc/zen/umps/util/PermissionUtil.kt

package com.gxzc.zen.umps.util

import com.gxzc.zen.umps.common.Permission
import org.slf4j.LoggerFactory
import org.springframework.util.Assert

/**
 *
 * @author NorthLan
 * @date 2018/2/6
 * @url https://noahlan.com
 */
object PermissionUtil {
    private val logger = LoggerFactory.getLogger(PermissionUtil::class.java)

    /**
     * 权限判定
     * @param needPermString 需要的权限
     * @param userPerm 用户权限列表
     */
    fun isPermitted(needPermString: String, userPerm: HashSet<String>): Boolean {
        try {
            assertPermissionString(needPermString)
            val userPermSet = convertToPermissionSet(userPerm)
            val needPerm = convertToPermission(needPermString)
            // 验证逻辑 platformId=0 为通用(超级)权限
            userPermSet
                    .filter { it.perm == needPerm.perm && verifyCRUD(needPerm.crud, it.crud) }
                    .forEach {
                        // 验证平台
                        return if (it.platformId == 0) {
                            true
                        } else {
                            it.platformId == needPerm.platformId
                        }
                    }
        } catch (e: RuntimeException) {
            logger.error("权限验证系统错误...", e)
            return false
        }
        return false
    }

    /**
     * 验证 CRUD 四项权限
     */
    private fun verifyCRUD(needCRUD: String, userCRUD: String): Boolean {
        needCRUD.forEach {
            if (it !in userCRUD) {
                return false
            }
        }
        return true
    }

    /**
     * 批量将权限串转换为权限实体
     */
    private fun convertToPermissionSet(perms: HashSet<String>): HashSet<Permission> {
        val result = hashSetOf<Permission>()
        perms.forEach({
            result.add(convertToPermission(it))
        })
        return result
    }

    /**
     * 将权限串转换为权限实体
     */
    private fun convertToPermission(str: String): Permission {
        return Permission(str)
    }

    private fun assertPermissionString(str: String) {
        Assert.notNull(str, "Permission string not be null.")
        val splitList = str.split(':')
        if (splitList.size < 3) {
            throw RuntimeException("permission字符串错误,必须为:分割且长度等于3")
        }
    }
}