src/lib/components/CountdownClock.svelte

@@ -0,0 +1,99 @@
+<script lang="ts">
+	import { onMount } from 'svelte';
+	import { dateDurationLong } from '$lib/util/Dates';
+
+	const FINAL_COUNTDOWN_MILLIS = 15 * 60 * 1000;
+
+	let { deadline }: { deadline: Date } = $props();
+	let deadlineMillis = $derived(deadline.valueOf());
+
+	let currentTime = $state(new Date().valueOf());
+	let timeLeft = $derived(Math.max(deadlineMillis - currentTime, 0));
+	let isFinalCountdown = $state(false);
+	$effect(() => {
+		// HACK: rndtrash: если дата обратного отчёта поменялась, то сбрасываем синхронизацию анимации
+		if (deadline || true) {
+			isFinalCountdown = false;
+		}
+	});
+
+	const padNumber = (n: number) => String(n).padStart(2, '0');
+	let secondsLeft = $derived(padNumber(Math.floor(timeLeft / 1000) % 60));
+	let minutesLeft = $derived(padNumber(Math.floor(timeLeft / 1000 / 60) % 60));
+	let hoursLeft = $derived(padNumber(Math.floor(timeLeft / 1000 / 60 / 60) % 24));
+
+	let daysLeft = $derived(Math.floor(timeLeft / 1000 / 60 / 60 / 24));
+
+	onMount(() => {
+		// HACK: rndtrash: NodeJS использует другой тип данных для интервалов
+		let interval: ReturnType<typeof setInterval> | undefined = undefined;
+
+		function updateTime() {
+			currentTime = new Date().valueOf();
+			isFinalCountdown = timeLeft <= FINAL_COUNTDOWN_MILLIS;
+		}
+
+		// В случае, если часы пререндернулись сервером, обновляем время вручную.
+		// Только потом используем специальную функцию, в том числе активирующую анимацию.
+		currentTime = new Date().valueOf();
+		interval = setInterval(updateTime, 1000);
+
+		return () => clearInterval(interval);
+	});
+</script>
+
+<div
+	class="flex flex-row flex-wrap items-center justify-center gap-2 text-2xl sm:gap-4 sm:text-4xl {isFinalCountdown
+		? 'final'
+		: ''}"
+>
+	{#if daysLeft > 0}
+		<div class="digit digitBlock">{dateDurationLong.format({ days: daysLeft })}</div>
+	{/if}
+	<div class="align-center flex flex-row flex-nowrap gap-1 align-middle">
+		<div class="digit digitBlock">{hoursLeft[0]}</div>
+		<div class="digit digitBlock">{hoursLeft[1]}</div>
+		<div class="digit">:</div>
+		<div class="digit digitBlock">{minutesLeft[0]}</div>
+		<div class="digit digitBlock">{minutesLeft[1]}</div>
+		<div class="digit">:</div>
+		<div class="digit digitBlock">{secondsLeft[0]}</div>
+		<div class="digit digitBlock">{secondsLeft[1]}</div>
+	</div>
+</div>
+
+<style>
+	@import '$src/app.css';
+
+	.digit {
+		@apply pt-0.5 font-bold sm:pt-1 sm:pb-0.5;
+	}
+
+	.digitBlock {
+		/* rndtrash: паддинг снизу по-меньше из-за оптического центра ьуквы */
+		@apply font-disket rounded-md border-2 border-slate-950 bg-slate-50 px-1.5 text-slate-950 sm:rounded-xl;
+
+		box-shadow: 0 2px var(--color-slate-950);
+	}
+
+	@media (prefers-reduced-motion: no-preference) {
+		.final {
+			.digitBlock {
+				animation: finalCountdownText 1s ease-in-out infinite;
+			}
+		}
+	}
+
+	@keyframes finalCountdownText {
+		0% {
+			color: var(--color-slate-950);
+		}
+		1% {
+			color: var(--color-red-700);
+		}
+		50%,
+		100% {
+			color: var(--color-slate-950);
+		}
+	}
+</style>

src/lib/util/Blogs.ts

@@ -1,6 +1,28 @@
 export const THUMBNAIL_DEFAULT = "https://teasanctuary.ru/common/background-day.webp";
 export const BLOG_POST_FRESHNESS_MILLIS = 3 * 24 * 60 * 60 * 1000; // 3 дня
 
+export enum EventStatus {
+	NotEvent = 0,
+	NotStarted,
+	InProgress,
+	IsOver
+}
+
+export function postEventStatus(post: App.BlogPost): EventStatus {
+	if (post.type !== 'event' || post.dateEventFrom === undefined || post.dateEventTo === undefined) {
+		return EventStatus.NotEvent;
+	}
+
+	const currentTime = new Date().valueOf();
+	const eventStart = new Date(post.dateEventFrom).valueOf();
+	if (currentTime < eventStart) return EventStatus.NotStarted;
+
+	const eventEnd = new Date(post.dateEventTo).valueOf();
+	if (currentTime < eventEnd) return EventStatus.InProgress;
+
+	return EventStatus.IsOver;
+}
+
 export type PostComparer = (a: App.BlogPost, b: App.BlogPost) => number;
 
 export const sortPostsByPostDate: PostComparer = (a, b) => new Date(b.date!).valueOf() - new Date(a.date!).valueOf();

src/routes/blog/[slug]/+page.svelte

@@ -1,12 +1,20 @@
 <script lang="ts">
 	import { page } from '$app/state';
-	import DateWidget from '$src/lib/components/DateWidget.svelte';
-	import InfoBlock from '$src/lib/components/InfoBlock.svelte';
+	import DateWidget from '$lib/components/DateWidget.svelte';
+	import InfoBlock from '$lib/components/InfoBlock.svelte';
 	import Icon from '@iconify/svelte';
 	import type { PageData } from './$types';
-	import { blogPostTypeToIcon, blogPostTypeToString } from '$src/lib/util/Blogs';
+	import {
+		blogPostTypeToIcon,
+		blogPostTypeToString,
+		EventStatus,
+		postEventStatus
+	} from '$lib/util/Blogs';
+	import { onMount } from 'svelte';
+	import { durationHumanReadable } from '$lib/util/Dates';
+	import CountdownClock from '$lib/components/CountdownClock.svelte';
 
-	export let data: PageData;
+	let { data }: { data: PageData } = $props();
 
 	const isPublic = !!data.blogPost.date;
 	const authors =
@@ -16,6 +24,28 @@
 				? [data.blogPost.authors]
 				: data.blogPost.authors;
 	const type: App.BlogPostType = data.blogPost.type ?? 'article';
+	let eventStatus = $state(EventStatus.NotEvent);
+
+	onMount(() => {
+		// HACK: rndtrash: NodeJS использует другой тип данных для таймаутов
+		let eventTimeout: ReturnType<typeof setTimeout> | undefined = undefined;
+		const updateStatus = () => {
+			eventStatus = postEventStatus(data.blogPost);
+			if (eventStatus !== EventStatus.NotEvent && eventStatus !== EventStatus.IsOver) {
+				const endpointString =
+					eventStatus === EventStatus.NotStarted
+						? data.blogPost.dateEventFrom!
+						: data.blogPost.dateEventTo!;
+				const delay = new Date(endpointString).valueOf() - new Date().valueOf();
+				if (delay <= 0) return;
+				// Плюс пол секунды, чтобы анимация часов успела проиграть
+				eventTimeout = setTimeout(updateStatus, delay + 500);
+			}
+		};
+		updateStatus();
+
+		return () => clearTimeout(eventTimeout);
+	});
 </script>
 
 <base target="_blank" />
@@ -63,6 +93,50 @@
 	{/each}
 </section>
 
+{#if type === 'event'}
+	<section
+		class="flex shrink-0 flex-col flex-wrap items-center justify-center p-2 font-bold
+		{eventStatus === EventStatus.NotStarted
+			? 'bg-amber-200'
+			: eventStatus === EventStatus.InProgress
+				? 'bg-green-600 text-slate-50'
+				: 'bg-slate-200'} gap-2"
+	>
+		{#if eventStatus === EventStatus.NotStarted || eventStatus === EventStatus.InProgress}
+			<span class="text-center text-4xl font-bold">
+				ДО {eventStatus === EventStatus.NotStarted ? 'НАЧАЛА' : 'КОНЦА'} ОСТАЛОСЬ
+			</span>
+			<CountdownClock
+				deadline={new Date(
+					eventStatus === EventStatus.NotStarted
+						? data.blogPost.dateEventFrom!
+						: data.blogPost.dateEventTo!
+				)}
+			/>
+		{:else if eventStatus === EventStatus.IsOver}
+			<span class="text-center text-4xl font-bold">СОБЫТИЕ ЗАВЕРШЕНО</span>
+		{/if}
+		<span class="flex flex-row flex-wrap items-center justify-center gap-2">
+			Событие {eventStatus === EventStatus.IsOver ? 'проводилось' : 'проводится'} с
+			<DateWidget
+				class="bg-slate-50 px-2 text-slate-950"
+				dateString={data.blogPost.dateEventFrom}
+				showTime
+			/>
+			по
+			<DateWidget
+				class="bg-slate-50 px-2 text-slate-950"
+				dateString={data.blogPost.dateEventTo}
+				showTime
+			/>
+			({durationHumanReadable(
+				new Date(data.blogPost.dateEventFrom!),
+				new Date(data.blogPost.dateEventTo!)
+			)})
+		</span>
+	</section>
+{/if}
+
 {#if page.data.blogPost.projects?.length > 0}
 	<InfoBlock>
 		<p>В данной заметке упоминаются наши проекты:</p>