1 files changed, 24 insertions, 0 deletions
diff --git a/web/src/frequently-used.js b/web/src/frequently-used.js
new file mode 100644
index 0000000..1601e03
--- /dev/null
+++ b/web/src/frequently-used.js
@@ -0,0 +1,24 @@
+// Copyright (c) 2020 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+const FREQUENTLY_USED = JSON.parse(window.localStorage.mauFrequentlyUsedStickerIDs || "{}")
+let FREQUENTLY_USED_SORTED = null
+
+export const add = id => {
+	const [count] = FREQUENTLY_USED[id] || [0]
+	FREQUENTLY_USED[id] = [count + 1, Date.now()]
+	window.localStorage.mauFrequentlyUsedStickerIDs = JSON.stringify(FREQUENTLY_USED)
+	FREQUENTLY_USED_SORTED = null
+}
+
+export const get = (limit = 16) => {
+	if (FREQUENTLY_USED_SORTED === null) {
+		FREQUENTLY_USED_SORTED = Object.entries(FREQUENTLY_USED)
+			.sort(([, [count1, date1]], [, [count2, date2]]) =>
+				count2 === count1 ? date2 - date1 : count2 - count1)
+			.map(([emoji]) => emoji)
+	}
+	return FREQUENTLY_USED_SORTED.slice(0, limit)
+}