import Link from "next/link";
import { PageHeader } from "@/components/page-header";
import { notFound } from "next/navigation";
import { getBookMeta, getSingleVerse, getChapterVerseIndex } from "@/lib/api";
import { ChapterViewer } from "@/app/books/chapter-viewer";
import type { MobileNavGroup } from "@/components/mobile-nav";

type BgMeta = {
  book: string;
  title: string;
  author: string;
  totalChapters: number;
  chapters: { number: number; title: string; totalVerses: number }[];
};

export default async function VersePage({
  params,
}: {
  params: Promise<{ chapter: string; verse: string }>;
}) {
  const { chapter, verse: verseParam } = await params;

  const meta = await getBookMeta("bg");
  if (!meta) notFound();

  const bgMeta = meta as unknown as BgMeta;
  const chapterInfo = bgMeta.chapters?.find(
    (c) => c.number === parseInt(chapter),
  );
  if (!chapterInfo?.title) notFound();

  const title: string = chapterInfo.title;

  const verseIndex = await getChapterVerseIndex("bg", null, parseInt(chapter));
  if (verseIndex.length === 0) notFound();

  const requestedVerse = parseInt(verseParam);
  const verse = await getSingleVerse(
    "bg",
    null,
    parseInt(chapter),
    requestedVerse,
  );
  if (!verse) notFound();

  // Build mobile nav groups — single flat list of chapters
  const mobileNavGroups: MobileNavGroup[] = [
    {
      title: "Chapters",
      items: bgMeta.chapters.map((ch) => ({
        slug: `${ch.number}`,
        label: `${ch.number}. ${ch.title}`,
        href: `/books/bg/${ch.number}/1`,
        type: "chapter",
      })),
    },
  ];

  return (
    <div className="min-h-screen bg-background">
      <PageHeader sticky wide>
        <Link
          href="/books/bg"
          className="text-sm text-muted-foreground hover:text-foreground"
        >
          &larr; Bhagavad-gītā
        </Link>
        <h1 className="mt-2 text-2xl font-bold text-foreground">
          Chapter {chapter}: {title}
        </h1>
      </PageHeader>

      <div className="w-full md:max-w-7xl mx-auto flex">
        <ChapterViewer
          initialVerse={verse}
          initialVerseNum={requestedVerse}
          verseIndex={verseIndex.map((v) => ({
            verse: v.verse,
            verseEnd: v.verseEnd ?? undefined,
            reference: v.reference,
          }))}
          book="bg"
          division={null}
          chapter={parseInt(chapter)}
          basePath={`/books/bg/${chapter}`}
          showBengali={false}
          mobileNavGroups={mobileNavGroups}
          mobileNavBookTitle="Bhagavad-gītā As It Is"
        />
      </div>
    </div>
  );
}