export const dynamic = "force-dynamic";

import type { Metadata } from "next";
import Link from "next/link";
import { notFound } from "next/navigation";
import {
  getJournalMeta,
  slugToBookCode,
  type JournalChapterEntry,
} from "@/lib/journals";
import { ogForJournal } from "@/lib/og";
import { PageHeader } from "@/components/layout/page-header";
import { Card, CardContent } from "@/components/ui/card";

export async function generateMetadata({
  params,
}: {
  params: Promise<{ slug: string }>;
}): Promise<Metadata> {
  const { slug } = await params;
  const bookCode = slugToBookCode(slug);
  const meta = await getJournalMeta(bookCode);
  const title = meta?.title ?? slug;
  return ogForJournal(title);
}

export default async function JournalIndexPage({
  params,
}: {
  params: Promise<{ slug: string }>;
}) {
  const { slug } = await params;
  const bookCode = slugToBookCode(slug);
  const meta = await getJournalMeta(bookCode);
  if (!meta) notFound();

  return (
    <div className="min-h-screen bg-background">
      <PageHeader>
        <Link
          href="/journals"
          className="text-sm text-muted-foreground hover:text-foreground transition-colors"
        >
          &larr; Journals
        </Link>
        <h1 className="mt-3 text-3xl font-bold text-foreground">
          {meta.title}
        </h1>
        <p className="mt-1 text-muted-foreground">{meta.author}</p>
      </PageHeader>

      <main className="max-w-5xl mx-auto px-6 py-8 space-y-8">
        {meta.description && (
          <p className="text-muted-foreground">{meta.description}</p>
        )}

        {meta.chapters.map((ch: JournalChapterEntry, idx: number) => {
          // Top-level chapter with a slug (Preface, Introduction, etc.)
          if ("slug" in ch && !("subChapters" in ch)) {
            return (
              <div key={ch.slug}>
                <Card>
                  <CardContent className="p-0">
                    <Link
                      href={`/journals/${slug}/${ch.slug}`}
                      className="flex items-center px-5 py-4 hover:bg-muted transition-colors"
                    >
                      <p className="font-medium text-foreground">{ch.title}</p>
                    </Link>
                  </CardContent>
                </Card>
              </div>
            );
          }

          // Group with sub-chapters (may be 2 or 3 levels deep)
          if ("subChapters" in ch) {
            const group = ch as {
              title: string;
              subChapters: {
                slug?: string;
                title: string;
                subChapters?: { slug: string; title: string }[];
              }[];
            };
            return (
              <div key={`group-${idx}`}>
                <h2 className="text-sm font-bold uppercase tracking-wider text-muted-foreground mb-3">
                  {group.title}
                </h2>
                <div className="space-y-4">
                  {group.subChapters.map((sc, scIdx) => {
                    // Sub-chapter with its own nested sub-chapters (e.g., month → days)
                    if ("subChapters" in sc && sc.subChapters) {
                      return (
                        <div key={`sc-${idx}-${scIdx}`}>
                          <h3 className="text-xs font-semibold uppercase tracking-wider text-muted-foreground mb-2 ml-1">
                            {sc.title}
                          </h3>
                          <Card className="divide-y divide-border">
                            <CardContent className="p-0">
                              <ul className="divide-y divide-border">
                                {sc.subChapters.map((day) => (
                                  <li key={day.slug}>
                                    <Link
                                      href={`/journals/${slug}/${day.slug}`}
                                      className="flex items-center px-5 py-3 hover:bg-muted transition-colors"
                                    >
                                      <p className="text-sm font-medium text-foreground">
                                        {day.title}
                                      </p>
                                    </Link>
                                  </li>
                                ))}
                              </ul>
                            </CardContent>
                          </Card>
                        </div>
                      );
                    }

                    // Direct sub-chapter with a slug (e.g., Summary, Notice)
                    if ("slug" in sc && sc.slug) {
                      return (
                        <Card key={`sc-${idx}-${scIdx}`}>
                          <CardContent className="p-0">
                            <Link
                              href={`/journals/${slug}/${sc.slug}`}
                              className="flex items-center px-5 py-3 hover:bg-muted transition-colors"
                            >
                              <p className="text-sm font-medium text-foreground">
                                {sc.title}
                              </p>
                            </Link>
                          </CardContent>
                        </Card>
                      );
                    }

                    return null;
                  })}
                </div>
              </div>
            );
          }

          return null;
        })}
      </main>
    </div>
  );
}