import {
  ArrowUpRight,
  CalendarDays,
  FolderKanban,
  Tag,
  UserRound,
} from "lucide-react";
import Link from "next/link";

import { MotionFade } from "@/components/motion-fade";
import { PortfolioCover } from "@/components/site/portfolio-cover";
import { AppCard } from "@/components/ui/app-card";
import { Button } from "@/components/ui/button";
import { CardContent } from "@/components/ui/card";
import { getLocalizedPath, type AppLocale } from "@/lib/locale";
import {
  getLocalizedValue,
  resolvePortfolioProjectViewMode,
  type PortfolioProjectView,
  type PortfolioSectionView,
} from "@/lib/portfolio";

type PortfolioProjectDetailProps = {
  item: PortfolioProjectView;
  locale: AppLocale;
  defaultLocale: AppLocale;
  t: (key: "back" | "preview" | "openLink" | "gallery" | "download") => string;
};

type ProjectImage = {
  key: string;
  src: string | null;
  label: string;
};

/**
 * All image sources for a project, in reading order: cover, gallery-section
 * images, then gallery assets. `src` may be null — PortfolioCover then renders
 * the branded placeholder, so layouts look intentional even without artwork.
 */
function collectImages(item: PortfolioProjectView, locale: AppLocale): ProjectImage[] {
  const images: ProjectImage[] = [];
  const coverTitle = getLocalizedValue(item.title, locale);

  images.push({ key: "cover", src: item.coverImagePath ?? null, label: coverTitle });

  for (const section of item.sections) {
    if (section.type === "GALLERY") {
      images.push({
        key: `section-${section.id}`,
        src: section.imagePath ?? null,
        label: getLocalizedValue(section.title, locale),
      });
    }
  }

  for (const asset of item.assets) {
    if (asset.kind === "IMAGE") {
      images.push({
        key: `asset-${asset.id}`,
        src: asset.filePath,
        label: getLocalizedValue(asset.alt, locale),
      });
    }
  }

  return images;
}

/** Text-bearing sections (everything that is not a gallery image). */
function textSections(item: PortfolioProjectView): PortfolioSectionView[] {
  return item.sections.filter((section) => section.type !== "GALLERY");
}

function MediaFrame({
  image,
  aspect = "aspect-[16/10]",
  chrome = false,
  priority = false,
}: {
  image: ProjectImage;
  aspect?: string;
  chrome?: boolean;
  priority?: boolean;
}) {
  return (
    <figure className="overflow-hidden rounded-surface border border-border bg-surface-2 shadow-card">
      {chrome ? (
        <div className="flex items-center gap-2 border-b border-border bg-surface-3 px-4 py-3">
          <span className="h-2.5 w-2.5 rounded-full bg-border-strong" />
          <span className="h-2.5 w-2.5 rounded-full bg-border-strong" />
          <span className="h-2.5 w-2.5 rounded-full bg-border-strong" />
          <span className="ms-3 h-5 flex-1 rounded-md bg-surface-1" />
        </div>
      ) : null}
      <div className={`group relative ${aspect}`}>
        <PortfolioCover src={image.src} title={image.label} priority={priority} />
      </div>
    </figure>
  );
}

function ProjectMeta({
  item,
  locale,
}: {
  item: PortfolioProjectView;
  locale: AppLocale;
}) {
  const metadata = [
    { icon: Tag, label: getLocalizedValue(item.category.name, locale) },
    { icon: CalendarDays, label: String(item.projectYear) },
    { icon: FolderKanban, label: getLocalizedValue(item.serviceLabel, locale) },
    { icon: UserRound, label: item.clientName },
  ].filter((entry) => entry.label);

  return (
    <div className="flex flex-wrap gap-3 text-sm text-foreground/80">
      {metadata.map((meta) => {
        const Icon = meta.icon;

        return (
          <span
            key={`${meta.label}-${Icon.name}`}
            className="inline-flex items-center gap-2 rounded-pill border border-border/70 bg-surface-2 px-3.5 py-1.5"
          >
            <Icon className="h-4 w-4 text-brand-primary" />
            {meta.label}
          </span>
        );
      })}
    </div>
  );
}

function BackLink({
  locale,
  defaultLocale,
  t,
}: {
  locale: AppLocale;
  defaultLocale: AppLocale;
  t: PortfolioProjectDetailProps["t"];
}) {
  return (
    <Button asChild variant="ghost" className="h-auto px-0 py-0 text-sm text-muted-foreground">
      <Link href={getLocalizedPath(locale, "/portfolio", defaultLocale)}>{t("back")}</Link>
    </Button>
  );
}

function PreviewButton({
  item,
  t,
  full = false,
}: {
  item: PortfolioProjectView;
  t: PortfolioProjectDetailProps["t"];
  full?: boolean;
}) {
  if (!item.previewUrl) {
    return null;
  }

  return (
    <Button asChild className={full ? "w-full justify-center" : undefined}>
      <Link href={item.previewUrl} target="_blank" rel="noreferrer">
        {t("preview")}
        <ArrowUpRight className="h-4 w-4" />
      </Link>
    </Button>
  );
}

function ProjectIntro({ item, locale }: { item: PortfolioProjectView; locale: AppLocale }) {
  return (
    <div className="space-y-4">
      <p className="text-overline uppercase tracking-[0.18em] text-brand-primary">
        {getLocalizedValue(item.category.name, locale)} · {item.projectYear}
      </p>
      <h1 className="text-h1 text-foreground">{getLocalizedValue(item.title, locale)}</h1>
      <p className="max-w-2xl text-body-lg text-muted-foreground">
        {getLocalizedValue(item.summary, locale)}
      </p>
    </div>
  );
}

function InfoPanel({
  item,
  locale,
  t,
}: {
  item: PortfolioProjectView;
  locale: AppLocale;
  t: PortfolioProjectDetailProps["t"];
}) {
  const rows = [
    { label: "Client", value: item.clientName },
    { label: "Year", value: String(item.projectYear) },
    { label: "Service", value: getLocalizedValue(item.serviceLabel, locale) },
    { label: "Category", value: getLocalizedValue(item.category.name, locale) },
  ].filter((row) => row.value);

  return (
    <AppCard level={2} className="lg:sticky lg:top-24">
      <CardContent className="space-y-5 p-6">
        <dl className="space-y-0">
          {rows.map((row, index) => (
            <div
              key={row.label}
              className={`flex items-center justify-between gap-4 py-2.5 text-sm ${
                index < rows.length - 1 ? "border-b border-dashed border-border" : ""
              }`}
            >
              <dt className="text-muted-foreground">{row.label}</dt>
              <dd className="font-semibold text-foreground">{row.value}</dd>
            </div>
          ))}
        </dl>
        <PreviewButton item={item} t={t} full />
      </CardContent>
    </AppCard>
  );
}

function TextSection({
  section,
  locale,
  t,
}: {
  section: PortfolioSectionView;
  locale: AppLocale;
  t: PortfolioProjectDetailProps["t"];
}) {
  const title = getLocalizedValue(section.title, locale);
  const body = getLocalizedValue(section.body, locale);

  return (
    <div className="space-y-3">
      <h3 className="text-h3 text-foreground">{title}</h3>
      {body ? (
        <p className="whitespace-pre-line text-body leading-7 text-muted-foreground">{body}</p>
      ) : null}
      {section.type === "LINK" && section.linkUrl ? (
        <Button asChild variant="outline">
          <Link href={section.linkUrl} target="_blank" rel="noreferrer">
            {t("openLink")}
            <ArrowUpRight className="h-4 w-4" />
          </Link>
        </Button>
      ) : null}
    </div>
  );
}

/* ============================================================
   WEB  (viewMode: CASE_STUDY)
   Two columns: stacked full screenshots + sticky info panel.
   ============================================================ */
function WebTemplate({ item, locale, defaultLocale, t }: PortfolioProjectDetailProps) {
  const images = collectImages(item, locale);
  const texts = textSections(item);

  return (
    <div className="space-y-8">
      <MotionFade>
        <div className="space-y-6">
          <BackLink locale={locale} defaultLocale={defaultLocale} t={t} />
          <ProjectIntro item={item} locale={locale} />
        </div>
      </MotionFade>

      <div className="grid gap-8 lg:grid-cols-[minmax(0,1fr)_340px] lg:items-start">
        <div className="order-2 space-y-6 lg:order-1">
          {images.map((image, index) => (
            <MotionFade key={image.key} delay={0.04 * index}>
              <MediaFrame image={image} chrome aspect="aspect-[16/11]" priority={index === 0} />
            </MotionFade>
          ))}

          {texts.length > 0 ? (
            <div className="grid gap-4 sm:grid-cols-2">
              {texts.map((section) => (
                <AppCard key={section.id}>
                  <CardContent className="p-5 lg:p-6">
                    <TextSection section={section} locale={locale} t={t} />
                  </CardContent>
                </AppCard>
              ))}
            </div>
          ) : null}
        </div>

        <aside className="order-1 lg:order-2">
          <InfoPanel item={item} locale={locale} t={t} />
        </aside>
      </div>
    </div>
  );
}

/* ============================================================
   PRINT  (viewMode: GRID)
   Gallery: mixed-size grid of images (logos, posters, ...).
   ============================================================ */
function PrintTemplate({ item, locale, defaultLocale, t }: PortfolioProjectDetailProps) {
  const images = collectImages(item, locale);
  const texts = textSections(item);

  return (
    <div className="space-y-10">
      <MotionFade>
        <div className="space-y-6">
          <BackLink locale={locale} defaultLocale={defaultLocale} t={t} />
          <ProjectIntro item={item} locale={locale} />
          <div className="flex flex-wrap items-center gap-3">
            <ProjectMeta item={item} locale={locale} />
            <PreviewButton item={item} t={t} />
          </div>
        </div>
      </MotionFade>

      <MotionFade delay={0.06}>
        <div className="grid auto-rows-[minmax(0,1fr)] grid-cols-2 gap-4 md:grid-cols-3">
          {images.map((image, index) => {
            // First image spans a large feature tile; the rest alternate size.
            const span =
              index === 0
                ? "col-span-2 row-span-2"
                : index % 4 === 0
                  ? "col-span-2"
                  : "";
            const aspect = index === 0 ? "aspect-square" : "aspect-[4/3]";

            return (
              <div key={image.key} className={span}>
                <MediaFrame image={image} aspect={index === 0 ? "aspect-square" : aspect} priority={index === 0} />
              </div>
            );
          })}
        </div>
      </MotionFade>

      {texts.length > 0 ? (
        <div className="grid gap-4 md:grid-cols-2">
          {texts.map((section) => (
            <MotionFade key={section.id} delay={0.04}>
              <AppCard>
                <CardContent className="p-6">
                  <TextSection section={section} locale={locale} t={t} />
                </CardContent>
              </AppCard>
            </MotionFade>
          ))}
        </div>
      ) : null}
    </div>
  );
}

/* ============================================================
   EDITORIAL  (viewMode: STORY)
   Full-bleed hero + alternating text / media sections.
   ============================================================ */
function EditorialTemplate({ item, locale, defaultLocale, t }: PortfolioProjectDetailProps) {
  const cover = collectImages(item, locale)[0]!;
  const sections = item.sections;
  const galleryImages = collectImages(item, locale).slice(1);

  return (
    <div className="space-y-6">
      <MotionFade>
        <BackLink locale={locale} defaultLocale={defaultLocale} t={t} />
      </MotionFade>

      <MotionFade delay={0.04}>
        <div className="relative flex min-h-[420px] items-end overflow-hidden rounded-surface border border-border">
          <div className="absolute inset-0">
            <PortfolioCover src={cover.src} title={cover.label} priority sizes="100vw" />
          </div>
          <div className="absolute inset-0 bg-gradient-to-t from-background/90 via-background/40 to-transparent" />
          <div className="relative z-10 max-w-3xl space-y-4 p-8 lg:p-12">
            <p className="text-overline uppercase tracking-[0.18em] text-brand-primary">
              {getLocalizedValue(item.category.name, locale)} · {item.projectYear}
            </p>
            <h1 className="text-display text-foreground">{getLocalizedValue(item.title, locale)}</h1>
          </div>
        </div>
      </MotionFade>

      <div className="flex flex-wrap items-center gap-3">
        <ProjectMeta item={item} locale={locale} />
        <PreviewButton item={item} t={t} />
      </div>

      <MotionFade delay={0.06}>
        <p className="max-w-3xl py-6 text-h3 font-medium leading-snug text-foreground/90">
          {getLocalizedValue(item.summary, locale)}
        </p>
      </MotionFade>

      <div className="space-y-16 py-4">
        {sections.map((section, index) => {
          if (section.type === "GALLERY") {
            return (
              <MotionFade key={section.id} delay={0.04}>
                <MediaFrame
                  image={{
                    key: section.id,
                    src: section.imagePath ?? null,
                    label: getLocalizedValue(section.title, locale),
                  }}
                  aspect="aspect-[16/8]"
                />
              </MotionFade>
            );
          }

          return (
            <MotionFade key={section.id} delay={0.04}>
              <div
                className={`grid items-center gap-8 lg:grid-cols-2 ${
                  index % 2 === 1 ? "lg:[&>*:first-child]:order-2" : ""
                }`}
              >
                <TextSection section={section} locale={locale} t={t} />
                <MediaFrame
                  image={galleryImages[index % Math.max(galleryImages.length, 1)] ?? cover}
                  aspect="aspect-[4/3]"
                />
              </div>
            </MotionFade>
          );
        })}
      </div>
    </div>
  );
}

export function PortfolioProjectDetail({
  item,
  locale,
  defaultLocale,
  t,
}: PortfolioProjectDetailProps) {
  const viewMode = resolvePortfolioProjectViewMode(item.viewMode);

  if (viewMode === "STORY") {
    return <EditorialTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
  }

  if (viewMode === "CASE_STUDY") {
    return <WebTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
  }

  return <PrintTemplate item={item} locale={locale} defaultLocale={defaultLocale} t={t} />;
}