"use client";

import { ExternalLink, FileText, Loader2 } from "lucide-react";
import type React from "react";
import { useEffect, useRef, useState } from "react";
import { MarkdownViewer } from "@/components/markdown-viewer";
import { Button } from "@/components/ui/button";
import { ScrollArea } from "@/components/ui/scroll-area";
import {
	Sheet,
	SheetContent,
	SheetDescription,
	SheetHeader,
	SheetTitle,
	SheetTrigger,
} from "@/components/ui/sheet";
import { useDocumentByChunk } from "@/hooks/use-document-by-chunk";
import { cn } from "@/lib/utils";

export const CitationDisplay: React.FC<{ index: number; node: any }> = ({ index, node }) => {
	const chunkId = Number(node?.id);
	const sourceType = node?.metadata?.source_type;
	const [isOpen, setIsOpen] = useState(false);
	const { document, loading, error, fetchDocumentByChunk, clearDocument } = useDocumentByChunk();
	const chunksContainerRef = useRef<HTMLDivElement>(null);
	const highlightedChunkRef = useRef<HTMLDivElement>(null);

	// Check if this is a source type that should render directly from node
	const isDirectRenderSource = sourceType === "TAVILY_API" || sourceType === "LINKUP_API";

	const handleOpenChange = async (open: boolean) => {
		setIsOpen(open);
		if (open && chunkId && !isDirectRenderSource) {
			await fetchDocumentByChunk(chunkId);
		} else if (!open && !isDirectRenderSource) {
			clearDocument();
		}
	};

	useEffect(() => {
		// Scroll to highlighted chunk when document loads
		if (document && highlightedChunkRef.current && chunksContainerRef.current) {
			setTimeout(() => {
				highlightedChunkRef.current?.scrollIntoView({
					behavior: "smooth",
					block: "start",
				});
			}, 100);
		}
	}, [document]);

	const handleUrlClick = (e: React.MouseEvent, url: string) => {
		e.preventDefault();
		e.stopPropagation();
		window.open(url, "_blank", "noopener,noreferrer");
	};

	const formatDocumentType = (type: string) => {
		return type
			.split("_")
			.map((word) => word.charAt(0) + word.slice(1).toLowerCase())
			.join(" ");
	};

	return (
		<Sheet open={isOpen} onOpenChange={handleOpenChange}>
			<SheetTrigger asChild>
				<span className="text-[10px] font-bold bg-slate-500 hover:bg-slate-600 text-white rounded-full w-4 h-4 inline-flex items-center justify-center align-super cursor-pointer transition-colors">
					{index + 1}
				</span>
			</SheetTrigger>
			<SheetContent side="right" className="w-full sm:max-w-5xl lg:max-w-7xl">
				<SheetHeader className="px-6 py-4 border-b">
					<SheetTitle className="flex items-center gap-3 text-lg">
						<FileText className="h-6 w-6" />
						{document?.title || node?.metadata?.title || node?.metadata?.group_name || "Source"}
					</SheetTitle>
					<SheetDescription className="text-base mt-2">
						{document
							? formatDocumentType(document.document_type)
							: sourceType && formatDocumentType(sourceType)}
					</SheetDescription>
				</SheetHeader>

				{!isDirectRenderSource && loading && (
					<div className="flex items-center justify-center h-64 px-6">
						<Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
					</div>
				)}

				{!isDirectRenderSource && error && (
					<div className="flex items-center justify-center h-64 px-6">
						<p className="text-sm text-destructive">{error}</p>
					</div>
				)}

				{/* Direct render for TAVILY_API and LINEAR_API */}
				{isDirectRenderSource && (
					<ScrollArea className="h-[calc(100vh-10rem)]">
						<div className="px-6 py-4">
							{/* External Link */}
							{node?.url && (
								<div className="mb-8">
									<Button
										size="default"
										variant="outline"
										onClick={(e) => handleUrlClick(e, node.url)}
										className="w-full py-3"
									>
										<ExternalLink className="mr-2 h-4 w-4" />
										Open in Browser
									</Button>
								</div>
							)}

							{/* Source Information */}
							<div className="mb-8 p-6 bg-muted/50 rounded-lg border">
								<h3 className="text-base font-semibold mb-4">Source Information</h3>
								<div className="text-sm text-muted-foreground mb-3 font-medium">
									{node?.metadata?.title || "Untitled"}
								</div>
								<div className="text-sm text-foreground leading-relaxed whitespace-pre-wrap">
									{node?.text || "No content available"}
								</div>
							</div>
						</div>
					</ScrollArea>
				)}

				{/* API-fetched document content */}
				{!isDirectRenderSource && document && (
					<ScrollArea className="h-[calc(100vh-10rem)]">
						<div className="px-6 py-4">
							{/* Document Metadata */}
							{document.document_metadata && Object.keys(document.document_metadata).length > 0 && (
								<div className="mb-8 p-6 bg-muted/50 rounded-lg border">
									<h3 className="text-base font-semibold mb-4">Document Information</h3>
									<dl className="grid grid-cols-1 gap-3 text-sm">
										{Object.entries(document.document_metadata).map(([key, value]) => (
											<div key={key} className="flex gap-3">
												<dt className="font-medium text-muted-foreground capitalize min-w-0 flex-shrink-0">
													{key.replace(/_/g, " ")}:
												</dt>
												<dd className="text-foreground break-words">{String(value)}</dd>
											</div>
										))}
									</dl>
								</div>
							)}

							{/* External Link */}
							{node?.url && (
								<div className="mb-8">
									<Button
										size="default"
										variant="outline"
										onClick={(e) => handleUrlClick(e, node.url)}
										className="w-full py-3"
									>
										<ExternalLink className="mr-2 h-4 w-4" />
										Open in Browser
									</Button>
								</div>
							)}

							{/* Chunks */}
							<div className="space-y-6" ref={chunksContainerRef}>
								<h3 className="text-base font-semibold mb-4">Document Content</h3>
								{document.chunks.map((chunk, idx) => (
									<div
										key={chunk.id}
										ref={chunk.id === chunkId ? highlightedChunkRef : null}
										className={cn(
											"p-6 rounded-lg border transition-all duration-300",
											chunk.id === chunkId
												? "bg-primary/10 border-primary shadow-md ring-1 ring-primary/20"
												: "bg-background border-border hover:bg-muted/50 hover:border-muted-foreground/20"
										)}
									>
										<div className="mb-4 flex items-center justify-between">
											<span className="text-sm font-medium text-muted-foreground">
												Chunk {idx + 1} of {document.chunks.length}
											</span>
											{chunk.id === chunkId && (
												<span className="text-sm font-medium text-primary bg-primary/10 px-3 py-1 rounded-full">
													Referenced Chunk
												</span>
											)}
										</div>
										<div className="text-sm text-foreground whitespace-pre-wrap leading-relaxed">
											<MarkdownViewer content={chunk.content} className="max-w-fit" />
										</div>
									</div>
								))}
							</div>
						</div>
					</ScrollArea>
				)}
			</SheetContent>
		</Sheet>
	);
};