Fetch conversations once, clean up ConversationController API (#1420)

* Fetch conversations once, clean up ConversationController API

Race conditions around re-fetching have caused some problems recently,
so this removes the need to re-fetch conversations. They are fetched
once or saved once, and that is it. All interaction goes through the
ConversationController, which is the central source of truth.

We have two rules for Conversations:

1. If a conversation is in the ConversationController it doesn't need
   to be fetched, but its initial fetch/save might be in progress. You
   can wait for that fetch/save with conversation.initialPromise.
2. If a conversation is not already in the ConversationController, it's
   not yet in the database. It needs to be added to the
   ConversationController and saved to the database.

FREEBIE

* Remove Conversation.fetch() call in Message.handleDataMessage()

FREEBIE

* ConversationController.API cleanup: Fix two missing spots

FREEBIE

js/models/conversations.js

@@ -59,6 +59,10 @@
         this.ourNumber = textsecure.storage.user.getNumber();
         this.verifiedEnum = textsecure.storage.protocol.VerifiedStatus;
 
+        // This may be overridden by ConversationController.getOrCreate, and signify
+        //   our first save to the database. Or first fetch from the database.
+        this.initialPromise = Promise.resolve();
+
         this.contactCollection = new Backbone.Collection();
         this.messageCollection = new Whisper.MessageCollection([], {
             conversation: this
@@ -87,7 +91,7 @@
         if (this.isPrivate()) {
             return Promise.all([
                 this.safeGetVerified(),
-                this.safeFetch()
+                this.initialPromise,
             ]).then(function(results) {
                 var trust = results[0];
                 // we don't return here because we don't need to wait for this to finish
@@ -103,12 +107,6 @@
             }.bind(this)).then(this.onMemberVerifiedChange.bind(this));
         }
     },
-    safeFetch: function() {
-        // new Promise necessary because a fetch will fail if convo not in db yet
-        return new Promise(function(resolve) {
-            this.fetch().always(resolve);
-        }.bind(this));
-    },
     setVerifiedDefault: function(options) {
         var DEFAULT = this.verifiedEnum.DEFAULT;
         return this.queueJob(function() {
@@ -801,28 +799,23 @@
         return _.contains(this.get('members'), number);
     },
     fetchContacts: function(options) {
-        return new Promise(function(resolve) {
-            if (this.isPrivate()) {
-                this.contactCollection.reset([this]);
-                resolve();
-            } else {
-                var promises = [];
-                var members = this.get('members') || [];
+        if (this.isPrivate()) {
+            this.contactCollection.reset([this]);
+            return Promise.resolve();
+        } else {
+            var members = this.get('members') || [];
+            var promises = members.map(function(number) {
+                return ConversationController.getOrCreateAndWait(number, 'private');
+            });
 
-                this.contactCollection.reset(
-                    members.map(function(number) {
-                        var c = ConversationController.create({
-                            id   : number,
-                            type : 'private'
-                        });
-                        this.listenTo(c, 'change:verified', this.onMemberVerifiedChange);
-                        promises.push(c.safeFetch());
-                        return c;
-                    }.bind(this))
-                );
-                resolve(Promise.all(promises));
-            }
-        }.bind(this));
+            return Promise.all(promises).then(function(contacts) {
+                _.forEach(contacts, function(contact) {
+                    this.listenTo(contact, 'change:verified', this.onMemberVerifiedChange);
+                }.bind(this));
+
+                this.contactCollection.reset(contacts);
+            }.bind(this));
+        }
     },
 
     destroyMessages: function() {
@@ -956,14 +949,11 @@
         }
 
         window.drawAttention();
-        var sender = ConversationController.create({
-            id: message.get('source'), type: 'private'
-        });
         var conversationId = this.id;
 
-        return new Promise(function(resolve, reject) {
-            sender.fetch().then(function() {
-                sender.getNotificationIcon().then(function(iconUrl) {
+        ConversationController.getOrCreateAndWait(message.get('source'), 'private')
+            .then(function(sender) {
+                return sender.getNotificationIcon().then(function(iconUrl) {
                     console.log('adding notification');
                     Whisper.Notifications.add({
                         title          : sender.getTitle(),
@@ -973,11 +963,8 @@
                         conversationId : conversationId,
                         messageId      : message.id
                     });
-
-                    return resolve();
-                }, reject);
-            }, reject);
-        });
+                });
+            });
     },
     hashCode: function() {
         if (this.hash === undefined) {
@@ -1054,20 +1041,6 @@
                 }
             }).always(resolve);
         }.bind(this));
-    },
-
-    fetchActive: function() {
-        // Ensures all active conversations are included in this collection,
-        // and updates their attributes, but removes nothing.
-        return this.fetch({
-            index: {
-                name: 'inbox', // 'inbox' index on active_at
-                order: 'desc'  // ORDER timestamp DESC
-                // TODO pagination/infinite scroll
-                // limit: 10, offset: page*10,
-            },
-            remove: false
-        });
     }
   });