dsec-notebook/src/routes/units/[code]/+page.svelte

<script lang="ts">
	import { mutation, query } from "$lib/api";
	import { page } from "$app/state";
	import { onMount } from "svelte";
	import { get } from "svelte/store";
	import FeedRow from "$lib/components/FeedRow.svelte";
	import { postPath } from "$lib/paths";
	import { getToken, initAuth, isAuthenticated } from "$lib/stores/auth";
	import { timeAgo } from "$lib/time";
	import type { NoteDoc, QuestionDoc, UnitDoc } from "$lib/types";

	const MAX_PINS = 10;

	let unit = $state<UnitDoc | null>(null);
	let notes: NoteDoc[] = $state([]);
	let questions: QuestionDoc[] = $state([]);
	let loading = $state(true);
	let authed = $state(false);
	let pinnedIds = $state<string[]>([]);
	let pinBusy = $state(false);
	let pinError = $state("");

	const isPinned = $derived(unit ? pinnedIds.includes(unit._id) : false);
	const canPin = $derived(isPinned || pinnedIds.length < MAX_PINS);

	onMount(async () => {
		await initAuth();
		authed = get(isAuthenticated);
		const token = getToken();

		const code = page.params.code;
		const u = await query("units:getByCode", { code });
		unit = u as UnitDoc;
		if (unit) {
			const [n, q, pins] = await Promise.all([
				query("notes:list", { unitId: unit._id }),
				query("questions:list", { unitId: unit._id }),
				token ? query("units:getPinned", { token }) : Promise.resolve([]),
			]);
			notes = n as NoteDoc[];
			questions = q as QuestionDoc[];
			pinnedIds = pins as string[];
		}
		loading = false;
	});

	async function togglePin() {
		if (!unit) return;

		const token = getToken();
		if (!token) {
			pinError = "Sign in to pin units";
			return;
		}

		pinBusy = true;
		pinError = "";
		try {
			pinnedIds = (await mutation(isPinned ? "units:unpin" : "units:pin", {
				token,
				unitId: unit._id,
			})) as string[];
		} catch (err: any) {
			pinError = err?.message ?? "Failed to update pin";
		} finally {
			pinBusy = false;
		}
	}
</script>

<svelte:head>
	<title>{unit?.code ?? "Unit"} — Notebook</title>
</svelte:head>

<div class="page">
	{#if loading}
		<p class="kicker py-16">Loading</p>
	{:else if unit}
		<p class="kicker"><a href="/" class="hover:text-primary">Home</a> · Unit</p>
		<div class="mt-2 flex items-center gap-2">
			<h1 class="text-ink font-serif text-4xl font-medium">
				{unit.code}{unit.code2 ? ` / ${unit.code2}` : ""}
			</h1>
			{#if authed}
				<button
					type="button"
					class="pin-btn {isPinned ? 'pin-btn-active' : ''}"
					onclick={togglePin}
					disabled={pinBusy || !canPin}
					title={isPinned
						? "Unpin unit"
						: canPin
							? "Pin unit"
							: "You can pin up to 10 units"}
					aria-label={isPinned ? "Unpin unit" : "Pin unit"}
				>
					<svg
						width="16"
						height="16"
						viewBox="0 0 24 24"
						fill="none"
						stroke="currentColor"
						stroke-width="2"
						stroke-linecap="round"
						stroke-linejoin="round"
						aria-hidden="true"
					>
						<path d="M12 17v5"></path>
						<path
							d="M9 10.76a2 2 0 0 1-1.11 1.79l-1.78.9A2 2 0 0 0 5 15.24V16h14v-.76a2 2 0 0 0-1.11-1.79l-1.78-.9A2 2 0 0 1 15 10.76V6h1a2 2 0 0 0 0-4H8a2 2 0 0 0 0 4h1z"
						></path>
					</svg>
				</button>
			{/if}
		</div>
		<p class="text-muted mt-1 text-[15px]">{unit.name}</p>
		{#if unit.description}
			<p class="text-muted mt-2 text-sm">{unit.description}</p>
		{/if}
		{#if pinError}
			<p class="text-primary mt-2 text-xs">{pinError}</p>
		{/if}

		{#if notes.length > 0}
			<p class="kicker border-rule mt-10 border-t pt-8">Notes</p>
			{#each notes as note}
				<FeedRow
					href={postPath(unit.code, note._id)}
					title={note.title}
					content={note.content}
					unitCode={unit.code + (unit.code2 ? ` / ${unit.code2}` : "")}
					meta="{note.authorName} · {timeAgo(
						note.createdAt,
					)} · {note.commentCount} comment{note.commentCount === 1 ? '' : 's'}"
					voteCount={note.voteCount}
					targetType="note"
					targetId={note._id}
				/>
			{/each}
		{/if}

		{#if questions.length > 0}
			<p class="kicker border-rule mt-10 border-t pt-8">Questions</p>
			{#each questions as question}
				<FeedRow
					href={postPath(unit.code, question._id)}
					title={question.title}
					content={question.content}
					unitCode={unit.code + (unit.code2 ? ` / ${unit.code2}` : "")}
					meta="{question.authorName} · {timeAgo(
						question.createdAt,
					)} · {question.answerCount} answer{question.answerCount === 1 ? '' : 's'}"
					voteCount={question.voteCount}
					targetType="question"
					targetId={question._id}
				/>
			{/each}
		{/if}

		{#if notes.length === 0 && questions.length === 0}
			<p class="text-muted mt-10 text-sm">No content for this unit yet.</p>
			<div class="mt-4 flex gap-4">
				<a href="/post/note" class="text-secondary hover:text-secondary-dark text-sm"
					>Post a note</a
				>
				<a href="/post/question" class="text-secondary hover:text-secondary-dark text-sm"
					>Ask a question</a
				>
			</div>
		{/if}
	{:else}
		<h1 class="text-ink font-serif text-3xl">Unit not found</h1>
		<a href="/" class="text-secondary hover:text-secondary-dark mt-2 inline-block text-sm"
			>Home</a
		>
	{/if}
</div>