closes #2379

also fixed a bug where tags with 0 topics were showing up in /tags

src/controllers/tags.js

@@ -49,7 +49,7 @@ tagsController.getTag = function(req, res, next) {
 };
 
 tagsController.getTags = function(req, res, next) {
-	topics.getTags(0, 99, function(err, tags) {
+	topics.getTags(0, 100, function(err, tags) {
 		if (err) {
 			return next(err);
 		}

src/socket.io/admin/tags.js

@@ -11,5 +11,9 @@ Tags.update = function(socket, data, callback) {
 	topics.updateTag(data.tag, data, callback);
 };
 
+Tags.deleteTags = function(socket, data, callback) {
+	topics.deleteTags(data.tags, callback);
+};
+
 
 module.exports = Tags;

src/topics/tags.js

@@ -64,7 +64,7 @@ module.exports = function(Topics) {
 	function updateTagCount(tag, callback) {
 		callback = callback || function() {};
 		Topics.getTagTopicCount(tag, function(err, count) {
-			if (!err) {
+			if (!err && count) {
 				db.sortedSetAdd('tags:topic:count', count, tag, callback);
 			}
 		});
@@ -78,13 +78,49 @@ module.exports = function(Topics) {
 		db.sortedSetCard('tag:' + tag + ':topics', callback);
 	};
 
+	Topics.deleteTags = function(tags, callback) {
+		if (!Array.isArray(tags) || !tags.length) {
+			return callback();
+		}
+
+		async.series([
+			function(next) {
+				removeTagsFromTopics(tags, next);
+			},
+			function(next) {
+				var keys = tags.map(function(tag) {
+					return 'tag:' + tag + ':topics';
+				});
+				db.deleteAll(keys, next);
+			},
+			function(next) {
+				db.sortedSetRemove('tags:topic:count', tags, next);
+			}
+		], callback);
+	};
+
+	function removeTagsFromTopics(tags, callback) {
+		async.eachLimit(tags, 50, function(tag, next) {
+			db.getSortedSetRange('tag:' + tag + ':topics', 0, -1, function(err, tids) {
+				if (err || !tids.length) {
+					return next(err);
+				}
+				var keys = tids.map(function(tid) {
+					return 'topic:' + tid + ':tags';
+				});
+
+				db.setsRemove(keys, tag, next);
+			});
+		}, callback);
+	}
+
 	Topics.deleteTag = function(tag) {
 		db.delete('tag:' + tag + ':topics');
 		db.sortedSetRemove('tags:topic:count', tag);
 	};
 
-	Topics.getTags = function(start, end, callback) {
-		db.getSortedSetRevRangeWithScores('tags:topic:count', start, end, function(err, tags) {
+	Topics.getTags = function(start, count, callback) {
+		db.getSortedSetRevRangeByScoreWithScores('tags:topic:count', start, count, '+inf', 1, function(err, tags) {
 			if (err) {
 				return callback(err);
 			}

src/views/admin/manage/tags.tpl

@@ -40,6 +40,7 @@
 			<div class="panel-body">
 				<p>Select tags via clicking and/or dragging, use shift to select multiple.</p>
 				<button class="btn btn-primary btn-md" id="modify">Modify Selected Tags</button>
+				<button class="btn btn-warning btn-md" id="deleteSelected">Delete Selected Tags</button>
 			</div>
 		</div>
 
@@ -50,5 +51,5 @@
 			</div>
 		</div>
 	</div>
-	
+
 </div>