refactor: render messages in sections

src/lib/chat.ts

@@ -1,7 +1,16 @@
-import { readable, type Readable } from 'svelte/store';
+import { derived, readable, type Readable } from 'svelte/store';
 import type { BlahChatServerConnection } from './blah/connection/chatServer';
 import type { BlahRichText } from './richText';
-import { messageFromBlah, type Chat, type Message } from './types';
+import { messageFromBlah, type Chat, type Message, type User } from './types';
+
+const MAX_MESSAGES_PER_SECTION = 10;
+const SHOW_TIME_AFTER_SILENCE = 30 * 60 * 1000;
+
+export type MessageSection = {
+	sender?: User;
+	messages: Message[];
+	date?: Date;
+};
 
 export function useChat(
 	server: BlahChatServerConnection,
@@ -9,6 +18,7 @@ export function useChat(
 ): {
 	info: Readable<Chat>;
 	messages: Readable<Message[]>;
+	sectionedMessages: Readable<MessageSection[]>;
 	sendMessage: (brt: BlahRichText) => Promise<void>;
 } {
 	const info = readable<Chat>(
@@ -37,9 +47,41 @@ export function useChat(
 		return unsubscribe;
 	});
 
+	const sectionedMessages = derived([messages], ([messages]) => {
+		const sections: MessageSection[] = [];
+
+		let lastMessage: Message | undefined = messages[0];
+		let currentSection: MessageSection = {
+			messages: [],
+			sender: lastMessage?.sender,
+			date: lastMessage?.date
+		};
+
+		for (const message of messages) {
+			const reachesMaxMessages = currentSection.messages.length >= MAX_MESSAGES_PER_SECTION;
+			const senderChanged = message.sender.id !== lastMessage.sender.id;
+			const silentForTooLong =
+				message.date.getTime() - lastMessage.date.getTime() > SHOW_TIME_AFTER_SILENCE;
+			if (reachesMaxMessages || senderChanged || silentForTooLong) {
+				if (currentSection.messages.length > 0) {
+					sections.push(currentSection);
+				}
+				currentSection = { messages: [], sender: message.sender };
+				if (silentForTooLong) currentSection.date = message.date;
+			}
+			currentSection.messages.push(message);
+			lastMessage = message;
+		}
+
+		sections.push(currentSection);
+
+		console.log(sections);
+		return sections;
+	});
+
 	const sendMessage = async (brt: BlahRichText) => {
 		await server.sendMessage(chatId, brt);
 	};
 
-	return { info, messages, sendMessage };
+	return { info, messages, sectionedMessages, sendMessage };
 }

src/lib/components/ServiceMessage.svelte

@@ -7,7 +7,7 @@
 
 <div
 	class={tw(
-		'backdrop mx-4 cursor-default rounded-full px-2 py-0.5 text-center backdrop-blur-sm',
+		'backdrop mx-4 inline-block cursor-default rounded-full px-2 py-0.5 text-center text-sm text-sf-secondary backdrop-blur-sm',
 		className
 	)}
 >

src/lib/formatters.ts

@@ -7,19 +7,29 @@ export function formatUnreadCount(count: number) {
 	return unreadCountFormatter.format(count);
 }
 
-const sameDayFormatter = new Intl.DateTimeFormat('default', {
-	hour: '2-digit',
-	minute: '2-digit'
-});
+const timeOptions: Intl.DateTimeFormatOptions = { hour: '2-digit', minute: '2-digit' };
+
+const sameDayFormatter = new Intl.DateTimeFormat('default', timeOptions);
 const sameYearFormatter = new Intl.DateTimeFormat('default', {
 	month: 'short',
 	day: 'numeric'
 });
+const sameYearWithTimeFormatter = new Intl.DateTimeFormat('default', {
+	month: 'short',
+	day: 'numeric',
+	...timeOptions
+});
 const otherYearFormatter = new Intl.DateTimeFormat('default', {
 	year: 'numeric',
 	month: 'short',
 	day: 'numeric'
 });
+const otherYearWithTimeFormatter = new Intl.DateTimeFormat('default', {
+	year: 'numeric',
+	month: 'short',
+	day: 'numeric',
+	...timeOptions
+});
 const fullDateTimeFormatter = new Intl.DateTimeFormat('default', {
 	year: 'numeric',
 	month: 'short',
@@ -29,9 +39,7 @@ const fullDateTimeFormatter = new Intl.DateTimeFormat('default', {
 	second: '2-digit'
 });
 
-export const formatMessageDate = (date: Date, full: boolean = false) => {
-	if (full) return fullDateTimeFormatter.format(date);
-
+export const formatMessageDate = (date: Date) => {
 	const now = new Date();
 	if (date.getFullYear() === now.getFullYear()) {
 		if (date.getMonth() === now.getMonth() && date.getDate() === now.getDate()) {
@@ -43,3 +51,19 @@ export const formatMessageDate = (date: Date, full: boolean = false) => {
 		return otherYearFormatter.format(date);
 	}
 };
+export const formatFullMessageDate = (date: Date) => {
+	return fullDateTimeFormatter.format(date);
+};
+
+export const formatMessageSectionDate = (date: Date) => {
+	const now = new Date();
+	if (date.getFullYear() === now.getFullYear()) {
+		if (date.getMonth() === now.getMonth() && date.getDate() === now.getDate()) {
+			return sameDayFormatter.format(date);
+		} else {
+			return sameYearWithTimeFormatter.format(date);
+		}
+	} else {
+		return otherYearWithTimeFormatter.format(date);
+	}
+};

src/routes/(app)/chats/[server]/[chatId]/+page.svelte

@@ -27,8 +27,8 @@
 
 <div class="flex h-full w-full flex-col items-center justify-center">
 	{#if server}
-		{@const { info, messages, sendMessage } = useChat(server, roomId)}
-		<ChatPage {info} {messages} on:sendMessage={(e) => sendMessage(e.detail)} />
+		{@const { info, sectionedMessages, sendMessage } = useChat(server, roomId)}
+		<ChatPage {info} {sectionedMessages} on:sendMessage={(e) => sendMessage(e.detail)} />
 	{:else}
 		<ServiceMessage>
 			To view this chat, you need to connect to chat server

src/routes/(app)/chats/[server]/[chatId]/ChatHeader.svelte

@@ -31,7 +31,7 @@
 		<h3 class="truncate text-sm font-semibold">{info.name}</h3>
 	</div>
 	<div class="sm:order-1">
-		<AvatarBeam size={30} name={info.id} />
+		<AvatarBeam size={32} name={info.id} />
 	</div>
 
 	<a class="absolute inset-y-0 start-0 hidden w-2 cursor-default sm:block" href="/">

src/routes/(app)/chats/[server]/[chatId]/ChatHistory.svelte

@@ -4,20 +4,47 @@
 	import type { Message } from '$lib/types';
 	import ChatMessage from './ChatMessage.svelte';
 	import { tick } from 'svelte';
+	import type { MessageSection } from '$lib/chat';
+	import { tw } from '$lib/tw';
+	import { AvatarBeam } from 'svelte-boring-avatars';
+	import ServiceMessage from '$lib/components/ServiceMessage.svelte';
+	import { formatMessageDate, formatMessageSectionDate } from '$lib/formatters';
 
-	export let messages: Message[] = [];
+	export let sectionedMessages: MessageSection[] = [];
 	export let mySenderId: string;
 
-	let ref: VList<Message> | undefined;
+	let ref: VList<MessageSection> | undefined;
 
 	async function scrollToIndex(index: number, smooth = true) {
 		await tick();
 		ref?.scrollToIndex(index, { align: 'end', smooth });
 	}
 
-	$: scrollToIndex(messages.length - 1);
+	$: scrollToIndex(sectionedMessages.length - 1);
 </script>
 
-<VList data={messages} let:item={message} class="size-full pt-2" bind:this={ref}>
-	<ChatMessage {message} isMyself={mySenderId === message.sender.id} />
+<VList data={sectionedMessages} let:item={messageSection} class="size-full pt-2" bind:this={ref}>
+	{@const isMyself = mySenderId === messageSection.sender?.id}
+
+	<div>
+		{#if messageSection.date}
+			<div class="py-0.5 text-center">
+				<ServiceMessage>{formatMessageSectionDate(messageSection.date)}</ServiceMessage>
+			</div>
+		{/if}
+		<div class={tw('flex w-full items-end px-2', isMyself && 'flex-row-reverse')}>
+			<div class="sticky bottom-1.5 mb-1.5 mt-1 w-8">
+				<AvatarBeam size={32} name={messageSection.sender?.id} />
+			</div>
+			<div class="flex-1">
+				{#each messageSection.messages as message, idx}
+					<ChatMessage
+						{message}
+						{isMyself}
+						showBubbleTail={messageSection.messages.length - 1 === idx}
+					/>
+				{/each}
+			</div>
+		</div>
+	</div>
 </VList>

src/routes/(app)/chats/[server]/[chatId]/ChatMessage.svelte

@@ -2,16 +2,13 @@
 	import RichTextRenderer from '$lib/components/RichTextRenderer.svelte';
 	import { tw } from '$lib/tw';
 	import type { Message } from '$lib/types';
-	import { AvatarBeam } from 'svelte-boring-avatars';
 
 	export let message: Message;
+	export let showBubbleTail: boolean = true;
 	export let isMyself: boolean;
 </script>
 
-<div class={tw('mb-2 flex items-end gap-2 px-2', isMyself && 'flex-row-reverse')}>
-	<div>
-		<AvatarBeam size={30} name={message.sender.name} />
-	</div>
+<div class={tw('mb-1.5 flex items-end gap-2 px-2', isMyself && 'flex-row-reverse')}>
 	<div
 		class={tw(
 			'relative flex-1',
@@ -24,6 +21,7 @@
 		<div
 			class={tw(
 				`relative inline-block max-w-[85%] rounded-2xl bg-[--weblah-chat-bubble-bg] shadow-sm ring-1 ring-[--weblah-chat-bubble-stroke]`,
+				showBubbleTail && [
 					// ::before: Fill of chat bubble tail
 					'before:absolute before:-bottom-[1px] before:box-content before:h-6 before:w-5 before:border-[--weblah-chat-bubble-bg] before:text-[--weblah-chat-bubble-stroke]',
 					isMyself
@@ -33,7 +31,8 @@
 					'after:absolute after:-bottom-[1px] after:-z-10 after:box-content after:h-6 after:w-5 after:text-[--weblah-chat-bubble-stroke]',
 					isMyself
 						? 'after:-end-5 after:rounded-es-[16px_12px] after:border-s-[10px] after:drop-shadow-[0_1px]'
-					: `after:-start-5 after:rounded-ee-[16px_12px] after:border-e-[10px] after:drop-shadow-[0_1px]`,
+						: `after:-start-5 after:rounded-ee-[16px_12px] after:border-e-[10px] after:drop-shadow-[0_1px]`
+				],
 				'sm:max-w-[70%] lg:max-w-[50%]',
 				isMyself && 'text-start'
 			)}

src/routes/(app)/chats/[server]/[chatId]/ChatPage.svelte

@@ -9,9 +9,10 @@
 	import ChatHistory from './ChatHistory.svelte';
 	import ChatInput from './ChatInput.svelte';
 	import type { BlahRichText } from '$lib/richText';
+	import type { MessageSection } from '$lib/chat';
 
 	export let info: Readable<Chat>;
-	export let messages: Readable<Message[]>;
+	export let sectionedMessages: Readable<MessageSection[]>;
 
 	interface $$Events {
 		sendMessage: CustomEvent<BlahRichText>;
@@ -20,6 +21,6 @@
 
 <ChatHeader info={$info} outsideUnreadCount={263723} />
 <BgPattern class="w-full flex-1" pattern="charlieBrown">
-	<ChatHistory messages={$messages} mySenderId={$currentKeyPair?.id} />
+	<ChatHistory sectionedMessages={$sectionedMessages} mySenderId={$currentKeyPair?.id} />
 </BgPattern>
 <ChatInput on:sendMessage />