export const dynamic = "force-dynamic";

import type { Metadata } from "next";
import Link from "next/link";
import { redirect, notFound } from "next/navigation";
import { ChevronRight } from "lucide-react";
import { getBookMeta, getProseChapter, getChapterVerseIndex } from "@/lib/api";
import { CC_LILAS } from "@/lib/constants";
import { buildOgMeta } from "@/lib/og";
import { PageHeader } from "@/components/layout/page-header";
import { Card, CardContent } from "@/components/ui/card";
import { buttonVariants } from "@/components/ui/button";
import { FindInPage } from "@/components/layout/find-in-page";
import { cn } from "@/lib/utils";

type ChapterInfo = { number: number; title: string; totalVerses: number };
type LilaInfo = {
  key: string;
  name: string;
  totalChapters: number;
  totalVerses: number;
  chapters: ChapterInfo[];
};

export async function generateMetadata({
  params,
}: {
  params: Promise<{ lila: string; chapter: string }>;
}): Promise<Metadata> {
  const { lila, chapter } = await params;
  const lilaName = CC_LILAS[lila] || lila;
  return buildOgMeta({
    title: "Śrī Caitanya-caritāmṛta",
    detail: `${lilaName}, Chapter ${chapter}`,
  });
}

export default async function CcChapterPage({
  params,
}: {
  params: Promise<{ lila: string; chapter: string }>;
}) {
  const { lila, chapter } = await params;
  const chapterNum = parseInt(chapter);

  const [meta, summary, verseIndex] = await Promise.all([
    getBookMeta("cc"),
    getProseChapter("cc", 0, `${lila}-${chapterNum}`),
    getChapterVerseIndex("cc", lila, chapterNum),
  ]);

  if (!meta) notFound();
  const lilaInfo = (meta.lilas as LilaInfo[] | undefined)?.find(
    (l) => l.key === lila,
  );
  if (!lilaInfo) notFound();
  const chapterInfo = lilaInfo.chapters.find((ch) => ch.number === chapterNum);
  if (!chapterInfo) notFound();
  if (verseIndex.length === 0) notFound();

  const firstVerse = verseIndex[0].verse;

  // Chapters without a summary (e.g. Ādi 7) go straight to the verses.
  if (!summary || summary.paragraphs.length === 0) {
    redirect(`/books/cc/${lila}/${chapterNum}/${firstVerse}`);
  }

  return (
    <div className="min-h-screen bg-background">
      <PageHeader sticky>
        <Link
          href={`/books/cc/${lila}`}
          className="text-sm text-muted-foreground hover:text-foreground transition-colors"
        >
          &larr; {lilaInfo.name}
        </Link>
        <div className="mt-3 flex items-start justify-between gap-3">
          <h1 className="text-2xl font-bold text-foreground">
            Chapter {chapterNum}: {chapterInfo.title}
          </h1>
          <FindInPage targetId="book-content" className="shrink-0 mt-0.5" />
        </div>
      </PageHeader>

      <main className="max-w-5xl mx-auto px-6 py-8 space-y-6">
        <p className="text-sm font-bold uppercase tracking-wider text-muted-foreground">
          Chapter Summary
        </p>
        <Card id="book-content">
          <CardContent className="py-8 px-6 sm:px-8">
            <div className="space-y-4">
              {summary.paragraphs.map((paragraph, i) => (
                <div
                  key={i}
                  className="text-base text-foreground leading-relaxed"
                  dangerouslySetInnerHTML={{ __html: paragraph }}
                />
              ))}
            </div>
          </CardContent>
        </Card>

        <Link
          href={`/books/cc/${lila}/${chapterNum}/${firstVerse}`}
          className={cn(buttonVariants({ size: "lg" }), "gap-2")}
        >
          Read the chapter
          <ChevronRight className="size-4" />
        </Link>
      </main>
    </div>
  );
}