import Link from "next/link";
import { Fragment } from "react";
import {
  Breadcrumb,
  BreadcrumbItem,
  BreadcrumbLink,
  BreadcrumbList,
  BreadcrumbPage,
  BreadcrumbSeparator,
} from "@/components/ui/breadcrumb";
import { JsonLd } from "@/components/json-ld";
import { site } from "@/content/site";

export type Crumb = { label: string; href?: string };

/**
 * Breadcrumbs (§6.3): visible trail + BreadcrumbList JSON-LD from the same data.
 * Pass the trail WITHOUT the Home root — it's prepended automatically.
 */
export function Breadcrumbs({
  items,
  className,
}: {
  items: Crumb[];
  className?: string;
}) {
  const trail: Crumb[] = [{ label: "Home", href: "/" }, ...items];

  const schema = {
    "@context": "https://schema.org",
    "@type": "BreadcrumbList",
    itemListElement: trail.map((c, i) => ({
      "@type": "ListItem",
      position: i + 1,
      name: c.label,
      ...(c.href ? { item: `${site.url}${c.href === "/" ? "" : c.href}` } : {}),
    })),
  };

  return (
    <>
      <Breadcrumb className={className}>
        <BreadcrumbList>
          {trail.map((c, i) => {
            const isLast = i === trail.length - 1;
            return (
              <Fragment key={`${c.label}-${i}`}>
                <BreadcrumbItem>
                  {isLast || !c.href ? (
                    <BreadcrumbPage>{c.label}</BreadcrumbPage>
                  ) : (
                    <BreadcrumbLink asChild>
                      <Link href={c.href}>{c.label}</Link>
                    </BreadcrumbLink>
                  )}
                </BreadcrumbItem>
                {isLast ? null : <BreadcrumbSeparator />}
              </Fragment>
            );
          })}
        </BreadcrumbList>
      </Breadcrumb>
      <JsonLd data={schema} />
    </>
  );
}