messages: Add `getMessages` and `status` functions to library

Apps/widgets should use the library instead of opening "messages.json"
For #2081

apps/messages/ChangeLog

@@ -63,3 +63,4 @@
 0.47: Add new Icons (Nextbike, Mattermost, etc.)
 0.48: When getting new message from the clock, only buzz once the messages app is loaded
 0.49: Change messages icon (to fit within 24px) and ensure widget renders icons centrally
+0.50: Add `getMessages` and `status` functions to library

apps/messages/app.js

@@ -48,7 +48,7 @@ we should start a timeout for settings.unreadTimeout to return
 to the clock. */
 var unreadTimeout;
 /// List of all our messages
-var MESSAGES = require("Storage").readJSON("messages.json",1)||[];
+var MESSAGES = require("messages").getMessages();
 if (!Array.isArray(MESSAGES)) MESSAGES=[];
 var onMessagesModified = function(msg) {
   // TODO: if new, show this new one

apps/messages/lib.js

@@ -102,6 +102,32 @@ exports.clearAll = function(event) {
     WIDGETS.messages.update(messages);
 }
 
+/**
+ * @returns {array} All messages
+ */
+exports.getMessages = function() {
+  if ("undefined"!=typeof MESSAGES) return MESSAGES; // loaded/managed by app
+  return require("Storage").readJSON("messages.json",1)||[];
+}
+
+/**
+ * Check if there are any messages
+ * @returns {string} "new"/"old"/"none"
+ */
+ exports.status = function() {
+  try {
+    let status= "none";
+    for(const m of exports.getMessages()) {
+      if (["music", "map"].includes(m.id)) continue;
+      if (m.new) return "new";
+      status = "old";
+    }
+    return status;
+  } catch(e) {
+    return "none"; // don't bother e.g. the widget with errors
+  }
+};
+
 exports.getMessageImage = function(msg) {
   /*
   * icons should be 24x24px or less with 1bpp colors and 'Transparency to Color'

apps/messages/metadata.json

@@ -1,7 +1,7 @@
 {
   "id": "messages",
   "name": "Messages",
-  "version": "0.49",
+  "version": "0.50",
   "description": "App to display notifications from iOS and Gadgetbridge/Android",
   "icon": "app.png",
   "type": "app",

apps/messages/widget.js

@@ -1,10 +1,5 @@
 (() => {
 
-function getMessages() {
-  if ("undefined"!=typeof MESSAGES) return MESSAGES;
-  return require("Storage").readJSON("messages.json",1)||[];
-}
-
 function filterMessages(msgs) {
   return msgs.filter(msg => msg.new && msg.id != "music")
     .map(m => m.src) // we only need this for icon/color
@@ -82,6 +77,5 @@ WIDGETS["messages"]={area:"tl", width:0, draw:function(recall) {
 message but then the watch was never viewed. In that case we don't
 want to buzz but should still show that there are unread messages. */
 if (global.MESSAGES===undefined)
-  WIDGETS["messages"].update(getMessages(), true);
-
+  WIDGETS["messages"].update(require("messages").getMessages(), true);
 })();