bundling experiments (WIP)

Looking at ways to bundle custom widgets with Grist. WIP,
experimental, everything will need rewrite.

app/common/CustomWidget.ts

@@ -1,3 +1,5 @@
+import sortBy = require('lodash/sortBy');
+
 /**
  * Custom widget manifest definition.
  */
@@ -8,6 +10,9 @@ export interface ICustomWidget {
   name: string;
   /**
    * Widget unique id, probably in npm package format @gristlabs/custom-widget-name.
+   *
+   * There could be multiple versions of the same widget with the
+   * same id, e.g. a bundled version and an external version.
    */
   widgetId: string;
   /**
@@ -25,6 +30,8 @@ export interface ICustomWidget {
    * a chance to apply the Grist theme.
    */
   renderAfterReady?: boolean;
+
+  fromPlugin?: string;
 }
 
 /**
@@ -56,3 +63,65 @@ export function isSatisfied(current: AccessLevel, minimum: AccessLevel) {
   }
   return ordered(current) >= ordered(minimum);
 }
+
+export function matchWidget(widgets: ICustomWidget[], options: {
+  widgetId?: string,
+  pluginId?: string,
+}): ICustomWidget|undefined {
+  console.log("MATCHING", {
+    widgets,
+    options,
+  });
+  const prefs = sortBy(widgets, (w) => {
+    return [w.widgetId !== options.widgetId,
+            (w.fromPlugin||'') !== options.pluginId]
+  });
+  if (prefs.length === 0) { return; }
+  if (options.widgetId && prefs[0].widgetId !== options.widgetId) {
+    return;
+  }
+  console.log("ORDERED", prefs);
+  console.log("MATCHED", prefs[0]);
+  return prefs[0];
+}
+
+export function filterWidgets(widgets: ICustomWidget[], options: {
+  preferPlugin?: boolean,
+  keepWidgetIdUnique?: boolean,
+}) {
+  const folders = new Map<string, ICustomWidget[]>();
+  for (const widget of widgets) {
+    const widgetId = widget.widgetId;
+    if (!folders.has(widgetId)) { folders.set(widgetId, []); }
+    const widgetFolder = folders.get(widgetId)!;
+    widgetFolder.push(widget);
+  }
+  let finalResults: ICustomWidget[] = widgets;
+  if (options.preferPlugin !== undefined) {
+    const results = [];
+    const seen = new Set<string>();
+    for (const widget of widgets) {
+      const folder = folders.get(widget.widgetId)!;
+      if (folder.length === 1) {
+        results.push(widget);
+        continue;
+      }
+      if (seen.has(widget.widgetId)) { continue; }
+      seen.add(widget.widgetId);
+      const folderSorted = sortBy(folder, (w) => Boolean(w.fromPlugin) !== options.preferPlugin);
+      results.push(folderSorted[0]!);
+    }
+    finalResults = results;
+  }
+  if (options.keepWidgetIdUnique) {
+    const results = [];
+    const seen = new Set<string>();
+    for (const widget of widgets) {
+      if (seen.has(widget.widgetId)) { continue; }
+      seen.add(widget.widgetId);
+      results.push(widget);
+    }
+    finalResults = results;
+  }
+  return finalResults;
+}