[PATCH v2 08/14] feat(lib/functions): add dateFormat() function

[Muhammad Rizki <kiizuha@gnuweeb.org>]

This commit introduces the dateFormat() function, which is used to
format datetime string returned by the API response. The formatted date
appears as follows: "Today at 09:00", "Yesterday at 09:00",
"Oct 02 at 09:00", and so on.

Signed-off-by: Muhammad Rizki <kiizuha@gnuweeb.org>
---
 src/lib/functions.ts | 29 +++++++++++++++++++++++++++++
 src/lib/index.ts     |  6 ++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/lib/functions.ts b/src/lib/functions.ts
index 510f13e..2928824 100644
--- a/src/lib/functions.ts
+++ b/src/lib/functions.ts
@@ -102,3 +102,32 @@ export const getRepliedMessage = (
     return msg.message_id === current.reply_to_message_id
   });
 }
+
+export const dateFormat = (date: string, amPm: boolean = false): string => {
+  const ts = new Date(date);
+  const today = new Date();
+
+  const tsDate = ts.getDate();
+  const todayDate = today.getDate();
+
+  const tsMonth = ts.getMonth();
+  const todayMonth = today.getMonth();
+
+  const tsYear = ts.getFullYear();
+  const todayYear = today.getFullYear();
+
+  const calc = todayDate - tsDate;
+  const localeTime = ts.toLocaleTimeString('en-US', { hour: '2-digit', minute: '2-digit', hour12: amPm });
+
+  if (tsDate === todayDate &&tsMonth === todayMonth && tsYear === todayYear) {
+    return `Today at ${localeTime}`;
+  } else if (calc === 1 && tsMonth === todayMonth && tsYear === todayYear) {
+    return `Yesterday at ${localeTime}`;
+  } else if (calc === -1 && tsMonth === todayMonth && tsYear === todayYear) {
+    return `Tomorrow at ${localeTime}`;
+  } else if (tsYear === todayYear) {
+    return `${tsDate} ${ts.toLocaleString('en-US', { month: 'short' })} at ${localeTime}`;
+  } else {
+    return `${ts.toLocaleString('en-US', { month: 'short', day: 'numeric', year: 'numeric' })} at ${localeTime}`;
+  }
+}
diff --git a/src/lib/index.ts b/src/lib/index.ts
index b62f0bd..2c71df5 100644
--- a/src/lib/index.ts
+++ b/src/lib/index.ts
@@ -9,7 +9,8 @@ import {
   getFixedRandomColor,
   cleanMessageText,
   setupUserName,
-  getRepliedMessage
+  getRepliedMessage,
+  dateFormat
 } from "./functions";
 
 export {
@@ -20,5 +21,6 @@ export {
   getFixedRandomColor,
   cleanMessageText,
   setupUserName,
-  getRepliedMessage
+  getRepliedMessage,
+  dateFormat
 };
-- 
Muhammad Rizki