import type { Metadata } from "next";
import Link from "next/link";
import { PageHeader } from "@/components/layout/page-header";
import { JsonLd } from "@/components/seo/json-ld";
import { bookJsonLd } from "@/lib/jsonld";
import { Card, CardContent } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { ExtractedVerseCount } from "../extracted-verse-count";
import { getBookMeta, getProseChapters } from "@/lib/api";
import { ogForBook } from "@/lib/og";
import { notFound } from "next/navigation";

export function generateMetadata(): Metadata {
  return ogForBook("sb");
}

type ChapterInfo = {
  number: number;
  title: string;
  totalVerses: number;
};

type CantoInfo = {
  number: number;
  title: string;
  totalChapters: number;
  chapters: ChapterInfo[];
};

export default async function SbPage() {
  const [meta, introSegments] = await Promise.all([
    getBookMeta("sb"),
    getProseChapters("sb", 0, "intro-segment"),
  ]);
  if (!meta) notFound();

  const intro = meta as {
    book: string;
    title: string;
    author: string;
    totalCantos: number;
    cantos: CantoInfo[];
  };

  return (
    <div className="min-h-screen bg-background">
      <JsonLd data={bookJsonLd({ path: "/books/sb", name: "Śrīmad-Bhāgavatam" })} />
      <PageHeader>
        <Link
          href="/books"
          className="text-sm text-muted-foreground hover:text-foreground"
        >
          &larr; Books
        </Link>
        <h1 className="mt-3 text-3xl font-bold text-foreground">
          {intro.title}
        </h1>
        <p className="mt-1 text-muted-foreground">{intro.author}</p>
      </PageHeader>
      <main className="max-w-5xl mx-auto px-6 py-8 space-y-8">
        {introSegments.length > 0 && (
          <div>
            <h2 className="text-sm font-bold uppercase tracking-wider text-muted-foreground mb-3">
              Front Matter
            </h2>
            <Card className="divide-y divide-border py-0">
              <CardContent className="p-0">
                <ul className="divide-y divide-border">
                  {introSegments.map((seg) => (
                    <li key={seg.slug}>
                      <Link
                        href={`/books/sb/${seg.slug}`}
                        className="flex px-5 py-4 hover:bg-muted transition-colors"
                      >
                        <p className="font-medium text-foreground">
                          {seg.title}
                        </p>
                      </Link>
                    </li>
                  ))}
                </ul>
              </CardContent>
            </Card>
          </div>
        )}

        <Card className="divide-y divide-border">
          <CardContent className="p-0">
            <ul className="divide-y divide-border">
              {intro.cantos.map((canto) => {
                const totalVerses = canto.chapters.reduce(
                  (sum, ch) => sum + ch.totalVerses,
                  0,
                );
                return (
                  <li key={canto.number}>
                    <Link
                      href={`/books/sb/${canto.number}`}
                      className="flex flex-col sm:flex-row sm:items-center sm:justify-between px-5 py-4 gap-1 sm:gap-0 hover:bg-muted transition-colors"
                    >
                      <div>
                        <Badge variant="secondary" className="mb-1">
                          Canto {canto.number}
                        </Badge>
                        <p className="font-medium text-foreground">
                          {canto.title}
                        </p>
                      </div>
                      <span className="text-sm text-muted-foreground sm:shrink-0 sm:ml-4">
                        {canto.totalChapters} chapters ·{" "}
                        <ExtractedVerseCount
                          count={totalVerses}
                          label="extracted verses"
                        />
                      </span>
                    </Link>
                  </li>
                );
              })}
            </ul>
          </CardContent>
        </Card>
      </main>
    </div>
  );
}