order User completions by last spoken

src/autocomplete/QueryMatcher.js

@@ -0,0 +1,62 @@
+//@flow
+
+import _at from 'lodash/at';
+import _flatMap from 'lodash/flatMap';
+import _sortBy from 'lodash/sortBy';
+import _sortedUniq from 'lodash/sortedUniq';
+import _keys from 'lodash/keys';
+
+class KeyMap {
+    keys: Array<String>;
+    objectMap: {[String]: Array<Object>};
+    priorityMap = new Map();
+}
+
+export default class QueryMatcher {
+    /**
+     * Given an array of objects and keys, returns a KeyMap
+     * Keys can refer to object properties by name and as in JavaScript (for nested properties)
+     *
+     * To use, simply presort objects by required criteria, run through this function and create a QueryMatcher with the
+     * resulting KeyMap.
+     *
+     * TODO: Handle arrays and objects (Fuse did this, RoomProvider uses it)
+     */
+    static valuesToKeyMap(objects: Array<Object>, keys: Array<String>): KeyMap {
+        const keyMap = new KeyMap();
+        const map = {};
+
+        objects.forEach((object, i) => {
+            const keyValues = _at(object, keys);
+            for (const keyValue of keyValues) {
+                if (!map.hasOwnProperty(keyValue)) {
+                    map[keyValue] = [];
+                }
+                map[keyValue].push(object);
+            }
+            keyMap.priorityMap.set(object, i);
+        });
+
+        keyMap.objectMap = map;
+        keyMap.keys = _keys(map);
+        return keyMap;
+    }
+
+    constructor(objects: Array<Object>, options: {[Object]: Object} = {}) {
+        this.options = options;
+        this.keys = options.keys;
+        this.setObjects(objects);
+    }
+
+    setObjects(objects: Array<Object>) {
+        this.keyMap = QueryMatcher.valuesToKeyMap(objects, this.keys);
+    }
+
+    match(query: String): Array<Object> {
+        query = query.toLowerCase().replace(/[^\w]/g, '');
+        const results = _sortedUniq(_sortBy(_flatMap(this.keyMap.keys, (key) => {
+            return key.toLowerCase().replace(/[^\w]/g, '').indexOf(query) >= 0 ? this.keyMap.objectMap[key] : [];
+        }), (candidate) => this.keyMap.priorityMap.get(candidate)));
+        return results;
+    }
+}