export const dynamic = "force-dynamic";

import Link from "next/link";
import { notFound } from "next/navigation";
import {
  getJournalContent,
  getJournalMeta,
  getJournalSidebarItems,
  slugToBookCode,
  type JournalSidebarItem,
} from "@/lib/journals";
import { PageHeader } from "@/components/page-header";
import { Card, CardContent } from "@/components/ui/card";
import { buttonVariants } from "@/components/ui/button";
import { ChevronLeft, ChevronRight } from "lucide-react";
import { cn } from "@/lib/utils";
import { MobileNav, type MobileNavGroup } from "@/components/mobile-nav";

export default async function JournalChapterPage({
  params,
}: {
  params: Promise<{ slug: string; chapter: string }>;
}) {
  const { slug, chapter: chapterSlug } = await params;
  const bookCode = slugToBookCode(slug);

  const [meta, content, sidebarItems] = await Promise.all([
    getJournalMeta(bookCode),
    getJournalContent(bookCode, chapterSlug),
    getJournalSidebarItems(bookCode),
  ]);

  if (!meta || !content) notFound();

  // Filter out heading items for prev/next navigation
  const navItems = sidebarItems.filter((item) => item.type !== "heading");
  const currentIdx = navItems.findIndex((item) => item.slug === chapterSlug);
  const prev = currentIdx > 0 ? navItems[currentIdx - 1] : null;
  const next =
    currentIdx < navItems.length - 1 ? navItems[currentIdx + 1] : null;

  return (
    <div className="min-h-screen bg-background">
      <PageHeader sticky>
        <Link
          href={`/journals/${slug}`}
          className="text-sm text-muted-foreground hover:text-foreground transition-colors"
        >
          &larr; {meta.title}
        </Link>
        <h1 className="mt-3 text-2xl font-bold text-foreground">
          {content.title}
        </h1>
      </PageHeader>

      <div className="max-w-5xl mx-auto flex">
        <ChapterSidebar
          items={sidebarItems}
          currentSlug={chapterSlug}
          docSlug={slug}
        />

        <main className="flex-1 min-w-0 px-6 py-8 space-y-8">
          <ChapterNav
            prev={prev}
            next={next}
            navItems={navItems}
            currentSlug={chapterSlug}
            docSlug={slug}
            docTitle={meta.title}
            showMobileNav
          />

          <Card>
            <CardContent className="py-8 px-6 sm:px-8">
              <div className="space-y-4">
                {content.paragraphs.map((paragraph, i) => (
                  <div
                    key={i}
                    className="text-base text-foreground leading-relaxed"
                    dangerouslySetInnerHTML={{ __html: paragraph }}
                  />
                ))}
              </div>
            </CardContent>
          </Card>

          <ChapterNav
            prev={prev}
            next={next}
            navItems={navItems}
            currentSlug={chapterSlug}
            docSlug={slug}
            docTitle={meta.title}
          />
        </main>
      </div>
    </div>
  );
}

function ChapterSidebar({
  items,
  currentSlug,
  docSlug,
}: {
  items: JournalSidebarItem[];
  currentSlug: string;
  docSlug: string;
}) {
  return (
    <aside className="hidden lg:block w-56 shrink-0 sticky top-[89px] self-start max-h-[calc(100vh-89px)] overflow-y-auto py-8 pr-4">
      <h2 className="text-xs font-bold uppercase tracking-wider text-muted-foreground mb-3 px-2">
        Chapters
      </h2>
      <nav className="flex flex-col gap-0.5">
        {items.map((item, i) =>
          item.type === "heading" ? (
            <h3
              key={`item-${i}`}
              className="text-xs font-bold uppercase tracking-wider text-muted-foreground mt-4 mb-1 px-2"
            >
              {item.label}
            </h3>
          ) : (
            <Link
              key={`item-${i}`}
              href={`/journals/${docSlug}/${item.slug}`}
              className={cn(
                "px-2 py-1.5 rounded-md text-sm transition-colors truncate",
                item.slug === currentSlug
                  ? "bg-primary/10 text-primary font-medium"
                  : "text-muted-foreground hover:bg-muted hover:text-foreground",
              )}
              title={item.label}
            >
              {item.label}
            </Link>
          ),
        )}
      </nav>
    </aside>
  );
}

function ChapterNav({
  prev,
  next,
  navItems,
  currentSlug,
  docSlug,
  docTitle,
  showMobileNav = false,
}: {
  prev: JournalSidebarItem | null;
  next: JournalSidebarItem | null;
  navItems: JournalSidebarItem[];
  currentSlug: string;
  docSlug: string;
  docTitle: string;
  showMobileNav?: boolean;
}) {
  const mobileNavGroups: MobileNavGroup[] = [];
  if (showMobileNav && navItems.length > 0) {
    mobileNavGroups.push({
      title: "Chapters",
      items: navItems.map((i) => ({
        slug: i.slug,
        label: i.label,
        href: `/journals/${docSlug}/${i.slug}`,
        type: i.type,
      })),
    });
  }

  return (
    <div className="flex items-center justify-between gap-3">
      <div className="flex items-center gap-2">
        {showMobileNav && (
          <MobileNav
            groups={mobileNavGroups}
            currentSlug={currentSlug}
            bookTitle={docTitle}
          />
        )}
        {prev ? (
          <Link
            href={`/journals/${docSlug}/${prev.slug}`}
            className={cn(
              buttonVariants({ variant: "outline", size: "sm" }),
              "gap-1.5",
            )}
          >
            <ChevronLeft className="size-4" />
            <span className="hidden sm:inline truncate max-w-[180px]">
              {prev.label}
            </span>
            <span className="sm:hidden">Previous</span>
          </Link>
        ) : (
          <div className="hidden lg:block" />
        )}
      </div>
      {next ? (
        <Link
          href={`/journals/${docSlug}/${next.slug}`}
          className={cn(
            buttonVariants({ variant: "outline", size: "sm" }),
            "gap-1.5",
          )}
        >
          <span className="hidden sm:inline truncate max-w-[180px]">
            {next.label}
          </span>
          <span className="sm:hidden">Next</span>
          <ChevronRight className="size-4" />
        </Link>
      ) : (
        <div />
      )}
    </div>
  );
}