"use client";

import * as React from "react";
import { useInfiniteScroll } from "@/app/(dashboard)/_hooks/use-infinite-scroll";
import { ContentCard } from "@/components/content-card";
import { Spinner } from "@/components/ui/spinner";
import { useAudio } from "@/providers/audio-provider";
import type { Content, PaginatedResponse } from "@/types/content";

interface ContentListProps {
	fetchFn: (params: {
		limit: number;
		offset: number;
	}) => Promise<PaginatedResponse<Content>>;
	title?: string;
}

export function ContentList({ fetchFn, title }: ContentListProps) {
	const { setActiveVideo } = useAudio();
	const [contents, setContents] = React.useState<Content[]>([]);
	const [loading, setLoading] = React.useState(true);
	const [offset, setOffset] = React.useState(0);
	const [hasMore, setHasMore] = React.useState(true);
	const containerRef = React.useRef<HTMLDivElement>(null);

	// biome-ignore lint/correctness/useExhaustiveDependencies: On a besoin de contents pour ré-attacher l'observer quand la liste change
	React.useEffect(() => {
		const observer = new IntersectionObserver(
			(entries) => {
				// On cherche l'entrée avec le plus grand ratio d'intersection parmi celles qui dépassent le seuil
				let bestEntry: IntersectionObserverEntry | null = null;
				let maxRatio = 0;

				for (const entry of entries) {
					if (entry.isIntersecting && entry.intersectionRatio > maxRatio) {
						maxRatio = entry.intersectionRatio;
						bestEntry = entry;
					}
				}

				if (bestEntry && maxRatio >= 0.6) {
					const contentId = bestEntry.target.getAttribute("data-content-id");
					if (contentId) {
						setActiveVideo(contentId);
					}
				}
			},
			{
				threshold: [0, 0.2, 0.4, 0.6, 0.8, 1.0], // Plusieurs seuils pour une détection plus fine du "meilleur"
				root: containerRef.current,
			},
		);

		const elements = containerRef.current?.querySelectorAll("[data-content-id]");
		elements?.forEach((el) => {
			observer.observe(el);
		});

		return () => observer.disconnect();
	}, [setActiveVideo, contents]);

	const fetchInitial = React.useCallback(async () => {
		setLoading(true);
		try {
			const response = await fetchFn({
				limit: 10,
				offset: 0,
			});
			setContents(response.data);
			setOffset(0);
			setHasMore(response.data.length === 10);
		} catch (error) {
			console.error("Failed to fetch contents:", error);
		} finally {
			setLoading(false);
		}
	}, [fetchFn]);

	React.useEffect(() => {
		fetchInitial();
	}, [fetchInitial]);

	const loadMore = React.useCallback(async () => {
		if (!hasMore || loading) return;

		setLoading(true);
		try {
			const response = await fetchFn({
				limit: 10,
				offset: offset + 10,
			});

			setContents((prev) => {
				const newIds = new Set(response.data.map((item) => item.id));
				const filteredPrev = prev.filter((item) => !newIds.has(item.id));
				return [...filteredPrev, ...response.data];
			});
			setOffset((prev) => prev + 10);
			setHasMore(response.data.length === 10);
		} catch (error) {
			console.error("Failed to load more contents:", error);
		} finally {
			setLoading(false);
		}
	}, [offset, hasMore, loading, fetchFn]);

	const { loaderRef } = useInfiniteScroll({
		hasMore,
		loading,
		onLoadMore: loadMore,
	});

	return (
		<div
			ref={containerRef}
			className="mx-auto px-4 h-screen flex flex-col justify-start items-center overflow-y-auto snap-y snap-mandatory no-scrollbar"
		>
			{title && <h1 className="text-2xl font-bold py-8">{title}</h1>}
			<div className="max-w-xl flex flex-col justify-start items-center">
				{contents.map((content) => (
					<div
						key={content.id}
						data-content-id={content.id}
						className="w-full snap-start snap-always py-4"
					>
						<ContentCard content={content} onUpdate={fetchInitial} />
					</div>
				))}
			</div>

			<div ref={loaderRef} className="py-8 flex justify-center">
				{loading && <Spinner className="h-8 w-8 text-primary" />}
				{!hasMore && contents.length > 0 && (
					<p className="text-muted-foreground text-sm italic">
						Vous avez atteint la fin ! 🐐
					</p>
				)}
				{!loading && contents.length === 0 && (
					<p className="text-muted-foreground text-sm italic">
						Aucun mème trouvé ici... pour l'instant !
					</p>
				)}
			</div>
		</div>
	);
}