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67import { useState, type ReactNode } from 'react';
import { ChevronRight } from 'lucide-react';
import { cn } from '@/lib/utils';
interface CollapsibleRegionProps {
/** Stable id used to derive heading and body element ids. */
id: string;
/** Visible heading text; also used as the landmark's accessible name. */
title: string;
defaultOpen?: boolean;
className?: string;
/** Applied to the expanded body wrapper (e.g. max-height, padding). */
bodyClassName?: string;
children: ReactNode;
}
/**
* Disclosure that is also a labelled landmark. Renders a `<section>` with
* `aria-labelledby` pointing at a visible `<h2>` inside the toggle button.
* Collapsed state hides the body from both screen readers and sighted users;
* the heading remains visible so the region stays discoverable.
*/
export function CollapsibleRegion({
id,
title,
defaultOpen = false,
className,
bodyClassName,
children,
}: CollapsibleRegionProps) {
const [open, setOpen] = useState(defaultOpen);
const headingId = `${id}-heading`;
const bodyId = `${id}-body`;
return (
<section
id={id}
aria-labelledby={headingId}
className={cn('border-b bg-white', className)}
>
<button
type="button"
aria-expanded={open}
aria-controls={bodyId}
onClick={() => setOpen((prev) => !prev)}
className="w-full flex items-center gap-2 px-4 py-3 text-left hover:bg-gray-50 focus:outline-2 focus:outline-uic-blue focus:outline-offset-[-2px]"
>
<ChevronRight
aria-hidden="true"
className={cn(
'w-4 h-4 text-muted-foreground transition-transform flex-shrink-0',
open && 'rotate-90',
)}
/>
<h2 id={headingId} className="text-sm font-medium">
{title}
</h2>
</button>
{open && (
<div id={bodyId} className={cn('max-h-[50vh] overflow-auto', bodyClassName)}>
{children}
</div>
)}
</section>
);
}