"use client";

import { format } from "date-fns";
import FuzzySearch from "fuzzy-search";
import Link from "next/link";
import { useMemo, useState } from "react";
import { Container } from "@/components/container";
import type { BlogEntry } from "./page";

function truncate(text: string, length: number) {
	return text.length > length ? `${text.slice(0, length)}…` : text;
}

function SearchIcon({ className }: { className?: string }) {
	return (
		<svg
			className={className}
			xmlns="http://www.w3.org/2000/svg"
			width="20"
			height="20"
			viewBox="0 0 24 24"
			fill="none"
			stroke="currentColor"
			strokeWidth="2"
			strokeLinecap="round"
			strokeLinejoin="round"
			aria-hidden="true"
			role="img"
		>
			<title>Search</title>
			<circle cx="11" cy="11" r="8" />
			<path d="m21 21-4.3-4.3" />
		</svg>
	);
}

export function BlogWithSearchMagazine({ blogs }: { blogs: BlogEntry[] }) {
	if (blogs.length === 0) {
		return (
			<div className="relative overflow-hidden bg-neutral-50 px-4 md:px-8 dark:bg-neutral-950">
				<Container className="relative pt-12 pb-24 md:pt-20">
					<p className="text-center text-neutral-500">No blog posts yet.</p>
				</Container>
			</div>
		);
	}

	// `blogs` arrives pre-sorted from the server: explicitly featured posts
	// first (ordered by `featured_order` asc, then date desc), then the rest
	// by date desc. If nothing is explicitly featured, fall back to treating
	// the newest post as the cover so the layout never feels empty up top.
	// `MagazineSearchGrid` re-filters using `heroSlugs` so the hero/featured
	// posts never duplicate into the archive grid.
	const explicitlyFeatured = blogs.filter((b) => b.featured);
	const heroBlogs = explicitlyFeatured.length > 0 ? explicitlyFeatured : blogs.slice(0, 1);
	const heroSlugs = new Set(heroBlogs.map((b) => b.slug));
	const [coverStory, ...secondaryFeatured] = heroBlogs;

	return (
		<div className="relative overflow-hidden bg-neutral-50 px-4 pt-20 md:px-8 dark:bg-neutral-950">
			<div className="pointer-events-none absolute inset-0 bg-[radial-gradient(ellipse_80%_50%_at_50%_-20%,rgba(120,119,198,0.15),transparent)] dark:bg-[radial-gradient(ellipse_80%_50%_at_50%_-20%,rgba(120,119,198,0.12),transparent)]" />
			<Container className="relative pt-12 pb-24 md:pt-20">
				<header className="mb-10 md:mb-14">
					<h1 className="text-4xl font-bold tracking-tight text-neutral-900 md:text-5xl dark:text-neutral-50">
						Blog
					</h1>
				</header>

				<MagazineFeatured blog={coverStory} />

				{secondaryFeatured.length > 0 ? (
					<MoreFeatured blogs={secondaryFeatured} />
				) : null}

				<MagazineSearchGrid blogs={blogs} excludedSlugs={heroSlugs} />
			</Container>
		</div>
	);
}

function MoreFeatured({ blogs }: { blogs: BlogEntry[] }) {
	return (
		<section aria-labelledby="more-featured-heading" className="mb-14">
			<h2
				id="more-featured-heading"
				className="mb-6 font-serif text-2xl font-medium text-neutral-900 dark:text-neutral-100"
			>
				More featured
			</h2>
			<ul className="grid gap-6 sm:grid-cols-2">
				{blogs.map((blog) => (
					<li key={blog.slug}>
						<MagazineCard blog={blog} />
					</li>
				))}
			</ul>
		</section>
	);
}

function MagazineFeatured({ blog }: { blog: BlogEntry }) {
	return (
		<Link
			href={blog.url}
			className="group/cover relative mb-14 block overflow-hidden rounded-3xl border border-neutral-200/80 bg-neutral-900 shadow-sm dark:border-neutral-800 dark:shadow-none"
		>
			<div className="md:aspect-[2.4/1] relative aspect-21/9 min-h-[220px]">
				{blog.image ? (
					<img
						src={blog.image}
						alt={blog.title}
						className="h-full w-full object-cover transition duration-500 group-hover/cover:scale-[1.03]"
					/>
				) : null}
				<div className="absolute inset-0 bg-linear-to-t from-black/85 via-black/35 to-transparent" />
				<div className="absolute inset-0 flex flex-col justify-end p-6 md:p-10">
					<span className="mb-2 inline-flex w-fit rounded-full bg-white/15 px-3 py-1 text-xs font-medium text-white backdrop-blur-sm">
						Cover story
					</span>
					<h2 className="max-w-3xl font-serif text-2xl leading-tight font-medium text-white md:text-4xl">
						{blog.title}
					</h2>
					<p className="mt-3 max-w-2xl text-sm text-white/85 md:text-base">
						{truncate(blog.description, 160)}
					</p>
					<div className="mt-5 flex flex-wrap items-center gap-3 text-sm text-white/90">
						<span className="flex items-center gap-2">
							<img
								src={blog.authorAvatar}
								alt={blog.author}
								width={28}
								height={28}
								className="h-7 w-7 rounded-full ring-2 ring-white/30"
							/>
							{blog.author}
						</span>
						<span className="text-white/50">·</span>
						<time dateTime={blog.date}>{format(new Date(blog.date), "MMMM d, yyyy")}</time>
					</div>
				</div>
			</div>
		</Link>
	);
}

function MagazineSearchGrid({
	blogs: allBlogs,
	excludedSlugs,
}: {
	blogs: BlogEntry[];
	/** Slugs already shown above the archive (cover story + "More featured"). */
	excludedSlugs: Set<string>;
}) {
	const [search, setSearch] = useState("");

	const searcher = useMemo(
		() =>
			new FuzzySearch(allBlogs, ["title", "description"], {
				caseSensitive: false,
			}),
		[allBlogs]
	);

	const gridItems = useMemo(() => {
		// When the reader is searching, surface every match (including
		// featured posts they may be looking for); otherwise hide the posts
		// that are already rendered as featured above the archive.
		const results = search.trim() ? searcher.search(search) : allBlogs;
		if (search.trim()) {
			return results;
		}
		return results.filter((b) => !excludedSlugs.has(b.slug));
	}, [search, searcher, allBlogs, excludedSlugs]);

	return (
		<section aria-labelledby="archive-heading">
			<div className="mb-8 flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
				<h2
					id="archive-heading"
					className="font-serif text-2xl font-medium text-neutral-900 dark:text-neutral-100"
				>
					From the archive
				</h2>
				<label className="relative w-full sm:max-w-md">
					<span className="sr-only">Search articles</span>
					<SearchIcon className="pointer-events-none absolute top-1/2 left-4 -translate-y-1/2 text-neutral-400" />
					<input
						type="search"
						value={search}
						onChange={(e) => setSearch(e.target.value)}
						placeholder="Search by title or topic…"
						className="w-full rounded-full bg-white py-3 pr-4 pl-12 text-sm text-neutral-800 shadow-sm ring-1 shadow-black/10 ring-black/10 transition outline-none placeholder:text-neutral-400 focus:border-neutral-400 focus:ring-2 focus:ring-neutral-200/80 dark:bg-neutral-900 dark:text-neutral-100 dark:placeholder:text-neutral-500 dark:focus:border-neutral-500 dark:focus:ring-neutral-700/50"
					/>
				</label>
			</div>

			{gridItems.length === 0 ? (
				<p className="rounded-2xl border border-dashed border-neutral-300 py-16 text-center text-neutral-500 dark:border-neutral-700 dark:text-neutral-400">
					No articles match that search.
				</p>
			) : (
				<ul className="grid gap-6 sm:grid-cols-2 lg:grid-cols-3">
					{gridItems.map((blog) => (
						<li key={blog.slug}>
							<MagazineCard blog={blog} />
						</li>
					))}
				</ul>
			)}
		</section>
	);
}

function MagazineCard({ blog }: { blog: BlogEntry }) {
	return (
		<Link
			href={blog.url}
			className="group/card flex h-full flex-col overflow-hidden rounded-2xl bg-white shadow-sm ring-1 shadow-black/10 ring-black/10 transition hover:-translate-y-0.5 hover:shadow-lg dark:border-neutral-800 dark:bg-neutral-900/50 dark:hover:border-neutral-700"
		>
			<div className="relative aspect-16/10 overflow-hidden bg-neutral-100 dark:bg-neutral-800">
				{blog.image ? (
					<img
						src={blog.image}
						alt={blog.title}
						className="h-full w-full object-cover transition duration-300 group-hover/card:scale-105"
					/>
				) : (
					<div className="flex h-full items-center justify-center text-neutral-400">No image</div>
				)}
			</div>
			<div className="flex flex-1 flex-col p-5">
				<time
					className="text-xs font-medium tracking-wider text-neutral-500 uppercase dark:text-neutral-400"
					dateTime={blog.date}
				>
					{format(new Date(blog.date), "MMM d, yyyy")}
				</time>
				<h3 className="mt-2 font-serif text-lg leading-snug font-medium text-neutral-900 dark:text-neutral-100">
					{blog.title}
				</h3>
				<p className="mt-2 flex-1 text-sm leading-relaxed text-neutral-600 dark:text-neutral-400">
					{truncate(blog.description, 110)}
				</p>
				<div className="mt-4 flex items-center gap-2 pt-4">
					<img
						src={blog.authorAvatar}
						alt={blog.author}
						width={24}
						height={24}
						className="h-6 w-6 rounded-full object-cover"
					/>
					<span className="text-xs text-neutral-600 dark:text-neutral-300">{blog.author}</span>
				</div>
			</div>
		</Link>
	);
}