From a04f03669c0c24a38d58dc6f631f45a4d53e3dd9 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Thu, 23 Jun 2016 10:36:16 +0100
Subject: [PATCH] RoomSettings: refactor permissions calculations

The logic for calculating who had permission for what was impenetrable (and
wrong, in parts), so rewrite it to be a bit clearer.
---
 src/components/views/rooms/RoomSettings.js | 72 ++++++++--------------
 1 file changed, 25 insertions(+), 47 deletions(-)

diff --git a/src/components/views/rooms/RoomSettings.js b/src/components/views/rooms/RoomSettings.js
index 8764700c5a..d6b8b67f25 100644
--- a/src/components/views/rooms/RoomSettings.js
+++ b/src/components/views/rooms/RoomSettings.js
@@ -22,6 +22,13 @@ var Modal = require('../../../Modal');
 var ObjectUtils = require("../../../ObjectUtils");
 var dis = require("../../../dispatcher");
 
+// parse a string as an integer; if the input is undefined, or cannot be parsed
+// as an integer, return a default.
+function parseIntWithDefault(val, def) {
+    var res = parseInt(val);
+    return isNaN(res) ? def : res;
+}
+
 module.exports = React.createClass({
     displayName: 'RoomSettings',
 
@@ -251,7 +258,7 @@ module.exports = React.createClass({
             power_levels_changed: true
         });
     },
-    
+
     _yankValueFromEvent: function(stateEventType, keyName, defaultValue) {
         // E.g.("m.room.name","name") would yank the "name" content key from "m.room.name"
         var event = this.props.room.currentState.getStateEvents(stateEventType, '');
@@ -286,7 +293,7 @@ module.exports = React.createClass({
             },
         });
     },
-    
+
     _onRoomAccessRadioToggle: function(ev) {
 
         //                         join_rule
@@ -368,58 +375,29 @@ module.exports = React.createClass({
         var EditableText = sdk.getComponent('elements.EditableText');
         var PowerSelector = sdk.getComponent('elements.PowerSelector');
 
-        var power_levels = this.props.room.currentState.getStateEvents('m.room.power_levels', '');
-        var events_levels = (power_levels ? power_levels.getContent().events : {}) || {};
         var cli = MatrixClientPeg.get();
         var roomState = this.props.room.currentState;
         var user_id = cli.credentials.userId;
 
-        if (power_levels) {
-            power_levels = power_levels.getContent();
+        var power_level_event = roomState.getStateEvents('m.room.power_levels', '');
+        var power_levels = power_level_event ? power_level_event.getContent() : {};
+        var events_levels = power_levels.events || {};
+        var user_levels = power_levels.users || {};
 
-            var ban_level = parseInt(power_levels.ban);
-            var kick_level = parseInt(power_levels.kick);
-            var redact_level = parseInt(power_levels.redact);
-            var invite_level = parseInt(power_levels.invite || 0);
-            var send_level = parseInt(power_levels.events_default || 0);
-            var state_level = parseInt(power_levels.state_default || 50);
-            var default_user_level = parseInt(power_levels.users_default || 0);
+        var ban_level = parseIntWithDefault(power_levels.ban, 50);
+        var kick_level = parseIntWithDefault(power_levels.kick, 50);
+        var redact_level = parseIntWithDefault(power_levels.redact, 50);
+        var invite_level = parseIntWithDefault(power_levels.invite, 50);
+        var send_level = parseIntWithDefault(power_levels.events_default, 0);
+        var state_level = power_level_event ? parseIntWithDefault(power_levels.state_default, 50) : 0;
+        var default_user_level = parseIntWithDefault(power_levels.users_default, 0);
 
-            if (power_levels.ban == undefined) ban_level = 50;
-            if (power_levels.kick == undefined) kick_level = 50;
-            if (power_levels.redact == undefined) redact_level = 50;
-
-            var user_levels = power_levels.users || {};
-
-            var current_user_level = user_levels[user_id];
-            if (current_user_level == undefined) current_user_level = default_user_level;
-
-            var power_level_level = events_levels["m.room.power_levels"];
-            if (power_level_level == undefined) {
-                power_level_level = state_level;
-            }
-
-            var can_change_levels = current_user_level >= power_level_level;
-        } else {
-            var ban_level = 50;
-            var kick_level = 50;
-            var redact_level = 50;
-            var invite_level = 0;
-            var send_level = 0;
-            var state_level = 0;
-            var default_user_level = 0;
-
-            var user_levels = [];
-            var events_levels = [];
-
-            var current_user_level = 0;
-
-            var power_level_level = 0;
-
-            var can_change_levels = false;
+        var current_user_level = user_levels[user_id];
+        if (current_user_level === undefined) {
+            current_user_level = default_user_level;
         }
 
-        var state_default = (parseInt(power_levels ? power_levels.state_default : 0) || 0);
+        var can_change_levels = roomState.mayClientSendStateEvent("m.room.power_levels", cli);
 
         var canSetTag = !cli.isGuest();
 
@@ -488,7 +466,7 @@ module.exports = React.createClass({
 
         var tagsSection = null;
         if (canSetTag || self.state.tags) {
-            var tagsSection = 
+            var tagsSection =
                 <div className="mx_RoomSettings_tags">
                     Tagged as: { canSetTag ?
                         (tags.map(function(tag, i) {