Added last update, cache strategy, telegram fail notifications, teachers photos

src/pages/[group].tsx

@@ -4,22 +4,27 @@ import { GetServerSidePropsContext, GetServerSidePropsResult } from 'next'
 import { getSchedule } from '@/app/agregator/schedule'
 import { NextSerialized, nextDeserializer, nextSerialized } from '@/app/utils/date-serializer'
 import { NavBar } from '@/widgets/navbar'
+import { LastUpdateAt } from '@/entities/last-update-at'
 
 type PageProps = NextSerialized<{
   schedule: Day[]
+  parsedAt: Date
 }>
 
 export default function HomePage(props: PageProps) {
-  const { schedule } = nextDeserializer(props)
+  const { schedule, parsedAt } = nextDeserializer(props)
 
   return (
     <>
       <NavBar />
+      <LastUpdateAt date={parsedAt} />
       <Schedule days={schedule} />
     </>
   )
 }
 
+const cachedSchedules = new Map<string, { lastFetched: Date, results: Day[] }>()
+const maxCacheDurationInMS = 1000 * 60 * 60
 export async function getServerSideProps(context: GetServerSidePropsContext<{ group: string }>): Promise<GetServerSidePropsResult<PageProps>> {
   const groups: { [group: string]: [number, string] } = {
     ps7: [146, 'ПС-7'],
@@ -27,11 +32,24 @@ export async function getServerSideProps(context: GetServerSidePropsContext<{ gr
   }
   const group = context.params?.group
   if (group && Object.hasOwn(groups, group) && group in groups) {
-    const schedule = await getSchedule(...groups[group])
+    let schedule
+    let parsedAt
+
+    const cachedSchedule = cachedSchedules.get(group)
+    if (cachedSchedule?.lastFetched && Date.now() - cachedSchedule.lastFetched.getTime() < maxCacheDurationInMS) {
+      schedule = cachedSchedule.results
+      parsedAt = cachedSchedule.lastFetched
+    } else {
+      schedule = await getSchedule(...groups[group])
+      parsedAt = new Date()
+      cachedSchedules.set(group, { lastFetched: new Date(), results: schedule })
+    }
+
     return {
-      props: {
-        schedule: nextSerialized(schedule)
-      }
+      props: nextSerialized({
+        schedule: schedule,
+        parsedAt: parsedAt
+      })
     }
   } else {
     return {