---
import FormattedDate from '../components/FormattedDate.astro';
import allLinks from '../data/links.ts';

type Link = (typeof allLinks)[number];

export interface Props {
	headingLevel?: 1 | 2 | 3 | 4 | 5 | 6,
	hideAuthor?: boolean,
	maxEntries?: number,
};

const { headingLevel = 2, hideAuthor = false, maxEntries } = Astro.props;

const headingElem = `h${headingLevel}`;
const subHeadingElem = `h${headingLevel + 1}`

const links: Link[] = maxEntries === undefined
	? allLinks
	: allLinks.sort(sortByDateAddedDescending).slice(0, maxEntries);

const distinctYears: string[] = links
	.map(link => link.isoDateAdded.slice(0,4))
	.reduce<string[]>((acc, curr) => acc.includes(curr) ? acc : [...acc, curr], [])
	.sort((a, b) => Number.parseInt(b) - Number.parseInt(a));

function matchesYear(year: string) {
	return (link: (typeof links)[number]) => link.isoDateAdded.slice(0,4) === year;
}

function sortByDateAddedDescending(link1: (typeof links)[number], link2: (typeof links)[number]) {
	const year1 = Number.parseInt(link1.isoDateAdded.slice(0, 4));
	const year2 = Number.parseInt(link2.isoDateAdded.slice(0, 4));
	const month1 = Number.parseInt(link1.isoDateAdded.slice(5, 7));
	const month2 = Number.parseInt(link2.isoDateAdded.slice(5, 7));
	const day1 = Number.parseInt(link1.isoDateAdded.slice(8, 10));
	const day2 = Number.parseInt(link2.isoDateAdded.slice(8, 10));

	if (year1 !== year2) {
		return year2 - year1;
	} else if (month1 !== month2) {
		return month2 - month1;
	} else {
		return day2 - day1;
	}
}

const canonicalLinksUrl = new URL('links', Astro.site)
---

<section class="h-feed">
	<Fragment set:html={`
		<${headingElem} class="p-name">
			My links
		</${headingElem}>
	`} />

	<aside>
		<p hidden={hideAuthor}>
			These links are collected by <a class="p-author h-card" href="/">Joe Carstairs</a>
		</p>

		<p hidden>
			<a class="u-url" href={canonicalLinksUrl}>Permalink</a>
		</p>
	</aside>

	{ distinctYears.map(year => (
		<Fragment set:html={`
			<${subHeadingElem}>
				${year}
			</${subHeadingElem}>
		`} />
		<ul>
			{ links.filter(matchesYear(year)).sort(sortByDateAddedDescending).map(link => (
				<li class="h-entry e-content">
					<a class="u-url p-name" href={link.href} set:html={link.title} />.
					<Fragment set:html={link.description} />
					Added: <FormattedDate date={link.isoDateAdded} />
				</li>
			)) }
		</ul>
	)) }

	{ (maxEntries !== undefined && maxEntries < allLinks.length)
		? <p class="full-feed-link"><a href="/links">All links</a></p>
		: <></>
	}
</section>