Handle messages with ForcedFetch class

Recently FB changes the API and it seems now a complex message
(e.g. a message with buttons) is not returned directly and has to be loaded
via /api/graphqlbatch

src/graphQLUtils.js

@@ -593,7 +593,27 @@ function graphQLBatch(ctx, defaultFuncs, query) {
     })
 }
 
+function loadMessage(ctx, defaultFuncs, threadID, messageId) {
+  var query = {
+    // This doc_id was valid on March 26th 2018.
+    doc_id: "1801329719924418",
+    query_params: {
+      thread_and_message_id: {
+        thread_id: threadID,
+        message_id: messageId
+      }
+    }
+  };
+
+  return graphQLBatch(ctx, defaultFuncs, query)
+    .then(function(resData) {
+      // TODO@ Figure out how to get the correct thread type
+      return formatMessageGraphQLResponse(threadID, undefined, resData.message);
+    })
+}
+
 module.exports = {
   formatMessageGraphQLResponse,
-  graphQLBatch
-}
+  graphQLBatch,
+  loadMessage
+};

src/listen.js

@@ -1,6 +1,7 @@
 "use strict";
 
 var utils = require("../utils");
+var graphQLUtils = require("./graphQLUtils");
 var log = require("npmlog");
 
 var msgsRecv = 0;
@@ -142,6 +143,7 @@ module.exports = function(defaultFuncs, api, ctx) {
         }
 
         var atLeastOne = false;
+        var pendingForceFetch = [];
         if (resData.ms) {
           msgsRecv += resData.ms.length;
           resData.ms
@@ -234,6 +236,10 @@ module.exports = function(defaultFuncs, api, ctx) {
                   });
                   break;
                 case "delta":
+                  if (v.delta.class === "ForcedFetch") {
+                    pendingForceFetch.push(v.delta);
+                    return;
+                  }
                   if (
                     ctx.globalOptions.pageID ||
                     (v.delta.class !== "NewMessage" &&
@@ -407,9 +413,18 @@ module.exports = function(defaultFuncs, api, ctx) {
         }
         return {
           resData: resData,
-          atLeastOne: atLeastOne,
+          atLeastOne: atLeastOne || pendingForceFetch.length > 0,
+          pendingForceFetch: pendingForceFetch,
         };
       })
+      .then(function(res) {
+        var pending = (res && res.pendingForceFetch) || [];
+        var promises = pending.map(e =>
+          graphQLUtils.loadMessage(ctx, defaultFuncs, e.threadKey.otherUserFbId, e.messageId)
+            .then(fmtMsg => globalCallback(null, fmtMsg)));
+        return Promise.all(promises)
+          .then(() => res)
+      })
       .then(function(res) {
         if (res && res.atLeastOne) {
           // Send deliveryReceipt notification to the server