From e76a428a3696ef0d5a5e6ba0fa39fe83b2612120 Mon Sep 17 00:00:00 2001
From: roshan-cinq <roshan@cinqueon.com>
Date: Fri, 20 Oct 2017 12:59:46 +0530
Subject: [PATCH] whichUsers function to check which users have permission over
 given resource

---
 lib/acl.js | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/lib/acl.js b/lib/acl.js
index 9851717..a6dfee3 100644
--- a/lib/acl.js
+++ b/lib/acl.js
@@ -607,6 +607,62 @@ Acl.prototype.permittedResources = function(roles, permissions, cb){
   }).nodeify(cb);
 }
 
+
+/**
+  whichUsers(resource, function(err, {resourceName: [permissions]})
+
+  Returns which users have permission over given resource.
+
+  whichUsers(role, permissions, function(err, resources) )
+
+  Returns which users have given permission over a resource.
+  
+  @param {String} Resource
+  @param {String} Permissions
+  @param {Function} Callback called wish the result.
+*/
+Acl.prototype.whichUsers = function (resource, permissions, cb) {
+  contract(arguments)
+    .params('string')
+    .params('string', 'string|array')
+    .params('string', 'function')
+    .params('string', 'string|array', 'function')
+    .end();
+
+  if (_.isFunction(permissions)) {
+    cb = permissions;
+    permissions = undefined;
+  } else if (permissions) {
+    permissions = makeArray(permissions);
+  }
+  return this.permittedUsers(resource, permissions, cb);
+};
+
+Acl.prototype.permittedUsers = function (resource, permissions, cb) {
+  var _this = this;
+  var result = _.isUndefined(permissions) ? {} : [];
+
+  return this.backend.getAsync(this.options.buckets.meta, 'roles').then(function (roles) {
+    return bluebird.all(roles.map(function (role) {
+      return _this._resourcePermissions([role], resource).then(function (p) {
+        if (permissions) {
+          var commonPermissions = _.intersection(permissions, p);
+          if (commonPermissions.length > 0) {
+            result.push(role);
+          }
+        } else {
+          result[role] = p;
+        }
+      });
+    })).then(function () {
+      return result;
+    });
+  }).nodeify(cb);
+
+}
+
+
+
 /**
   clean ()