"use server";

import { revalidatePath } from "next/cache";
import { requireAdmin } from "../../lib/auth";
import {
  BLOCK_TYPES,
  RESERVED_SLUGS,
  createContentBlock,
  createPage,
  deleteContentBlock,
  deletePage,
  getContentBlock,
  getPage,
  listContentBlocks,
  moveContentBlock,
  movePageNav,
  saveMediaUpload,
  updateBlockContent,
  updatePageNavLabel,
  updatePageSeo,
  upsertBlockTranslation,
  upsertPageTranslation,
  type BlockType,
  type PageSlug,
} from "../../lib/cms";
import { DEFAULT_LANG, isLang, type Lang } from "../../lib/i18n";
import { isRichtextVariant } from "../../lib/richtextVariants";
import { sanitizeHtml } from "../../lib/sanitize";

type Result = { error: string | null };

function revalidateWebsite(slug?: PageSlug) {
  revalidatePath("/website");
  if (slug) revalidatePath(`/website/${slug}`);
}

const SLUG_PATTERN = /^[a-z0-9-]+$/;
const BLOCK_KEY_PATTERN = /^[a-z0-9_-]+$/;

export async function createPageAction(slug: string, title: string): Promise<Result & { slug?: string }> {
  await requireAdmin();
  const cleanSlug = slug.trim().toLowerCase();
  const cleanTitle = title.trim();

  if (!cleanSlug || !cleanTitle) return { error: "Vul een slug en een titel in." };
  if (!SLUG_PATTERN.test(cleanSlug)) return { error: "Slug mag alleen kleine letters, cijfers en koppeltekens bevatten." };
  if (RESERVED_SLUGS.includes(cleanSlug)) return { error: "Deze slug is gereserveerd. Kies een andere." };
  if (getPage(cleanSlug)) return { error: "Er bestaat al een pagina met deze slug." };

  createPage(cleanSlug, cleanTitle, cleanTitle);
  revalidateWebsite();
  return { error: null, slug: cleanSlug };
}

export async function deletePageAction(slug: PageSlug): Promise<Result> {
  await requireAdmin();
  if (!getPage(slug)) return { error: "Onbekende pagina." };
  deletePage(slug);
  revalidateWebsite();
  return { error: null };
}

export async function movePageNavAction(slug: PageSlug, direction: "up" | "down") {
  await requireAdmin();
  movePageNav(slug, direction === "up" ? "up" : "down");
  revalidateWebsite();
}

export async function updatePageNavAction(slug: PageSlug, navLabel: string, lang: Lang = DEFAULT_LANG): Promise<Result> {
  await requireAdmin();
  if (!isLang(lang)) return { error: "Onbekende taal." };
  if (!getPage(slug)) return { error: "Onbekende pagina." };

  // EN/DE: alleen het vertaalde label; of en waar de pagina in het menu staat, bepaalt NL
  if (lang !== DEFAULT_LANG) upsertPageTranslation(slug, lang, { nav_label: navLabel.trim() });
  else updatePageNavLabel(slug, navLabel.trim() || null);
  revalidateWebsite(slug);
  return { error: null };
}

export async function updatePageSeoAction(
  slug: PageSlug,
  metaTitle: string,
  metaDescription: string,
  ogImage: string,
  canonicalUrl: string,
  noindex: boolean,
  lang: Lang = DEFAULT_LANG
): Promise<Result> {
  await requireAdmin();
  if (!isLang(lang)) return { error: "Onbekende taal." };
  if (!getPage(slug)) return { error: "Onbekende pagina." };

  if (lang !== DEFAULT_LANG) {
    // EN/DE: alleen titel en omschrijving (leeg = NL); og:image, canonical en noindex gelden voor alle talen
    upsertPageTranslation(slug, lang, { meta_title: metaTitle.trim(), meta_description: metaDescription.trim() });
    revalidateWebsite(slug);
    return { error: null };
  }

  if (!metaTitle.trim()) return { error: "Meta-titel is verplicht." };
  const canonical = canonicalUrl.trim();
  if (canonical && !/^https?:\/\//i.test(canonical)) return { error: "Canonieke URL moet met http(s):// beginnen." };

  updatePageSeo(slug, metaTitle.trim(), metaDescription.trim(), ogImage.trim() || null, canonical || null, Boolean(noindex));
  revalidateWebsite(slug);
  return { error: null };
}

// Velden per bloktype die opgeslagen mogen worden; de rest wordt genegeerd
const BLOCK_FIELDS: Record<BlockType, string[]> = {
  hero: ["heading", "text", "image", "buttonLabel", "buttonHref"],
  richtext: ["heading", "body", "buttonLabel", "buttonHref"],
  testimonial: ["quote", "attribution", "image"],
  benefits: ["heading", "items"],
  cta: ["heading", "body", "buttonLabel", "buttonHref"],
};

// Rich-text-velden (HTML) worden gesaniteerd vóór opslag
const HTML_FIELDS: Record<BlockType, string[]> = {
  hero: ["heading", "text"],
  richtext: ["heading", "body"],
  testimonial: ["quote"],
  benefits: ["heading"],
  cta: ["heading", "body"],
};

const SAFE_HREF = /^(\/(?!\/)|#|https?:\/\/|mailto:|tel:)/i;
const SAFE_IMAGE = /^(\/(?!\/)|https?:\/\/)/i;

export async function updateBlockAction(
  blockId: number,
  slug: PageSlug,
  content: Record<string, unknown>,
  lang: Lang = DEFAULT_LANG
): Promise<Result> {
  await requireAdmin();
  if (!isLang(lang)) return { error: "Onbekende taal." };

  // Type en pagina komen uit de database, niet van de client
  const block = getContentBlock(blockId);
  if (!block || block.page_slug !== slug) return { error: "Blok niet gevonden op deze pagina." };

  const clean: Record<string, unknown> = {};
  for (const field of BLOCK_FIELDS[block.type]) {
    const value = content[field];
    if (field === "items") {
      if (Array.isArray(value)) {
        clean.items = value
          .filter((item): item is string => typeof item === "string")
          .map((item) => sanitizeHtml(item))
          .filter((item) => item.trim().length > 0);
      }
    } else if (typeof value === "string") {
      clean[field] = HTML_FIELDS[block.type].includes(field) ? sanitizeHtml(value) : value.trim();
    }
  }
  if (typeof clean.buttonHref === "string" && clean.buttonHref && !SAFE_HREF.test(clean.buttonHref)) {
    return { error: "Knoplink moet beginnen met /, #, http(s)://, mailto: of tel:." };
  }
  if (typeof clean.image === "string" && clean.image && !SAFE_IMAGE.test(clean.image)) {
    return { error: "Ongeldige afbeelding." };
  }

  // Weergave van een tekstblok: alleen via NL, geldt voor alle talen
  if (block.type === "richtext" && lang === DEFAULT_LANG && isRichtextVariant(content.variant) && content.variant !== "standaard") {
    clean.variant = content.variant;
  }

  if (lang === DEFAULT_LANG) updateBlockContent(blockId, clean);
  // EN/DE: een vertaling zonder tekst wordt verwijderd, zodat "ingevuld" altijd echte tekst betekent
  else upsertBlockTranslation(blockId, block.type, lang, clean);
  revalidateWebsite(slug);
  return { error: null };
}

export async function createContentBlockAction(
  slug: PageSlug,
  type: BlockType,
  label: string,
  blockKey: string
): Promise<Result> {
  await requireAdmin();
  if (!getPage(slug)) return { error: "Onbekende pagina." };
  if (!BLOCK_TYPES.includes(type)) return { error: "Onbekend bloktype." };

  const cleanLabel = label.trim();
  const cleanKey = blockKey.trim().toLowerCase();
  if (!cleanLabel) return { error: "Vul een naam voor het blok in." };
  if (!BLOCK_KEY_PATTERN.test(cleanKey)) return { error: "Blok-sleutel mag alleen kleine letters, cijfers, - en _ bevatten." };
  if (listContentBlocks(slug).some((b) => b.block_key === cleanKey)) {
    return { error: "Er bestaat al een blok met deze sleutel op deze pagina." };
  }

  createContentBlock(slug, cleanKey, type, cleanLabel);
  revalidateWebsite(slug);
  return { error: null };
}

export async function deleteContentBlockAction(blockId: number, slug: PageSlug): Promise<Result> {
  await requireAdmin();
  const block = getContentBlock(blockId);
  if (!block || block.page_slug !== slug) return { error: "Blok niet gevonden op deze pagina." };
  deleteContentBlock(blockId);
  revalidateWebsite(slug);
  return { error: null };
}

export async function moveContentBlockAction(blockId: number, slug: PageSlug, direction: "up" | "down") {
  await requireAdmin();
  moveContentBlock(blockId, slug, direction === "up" ? "up" : "down");
  revalidateWebsite(slug);
}

export async function uploadMediaAction(formData: FormData): Promise<{ path: string | null; error: string | null }> {
  await requireAdmin();
  const file = formData.get("file");
  if (!(file instanceof File) || file.size === 0) return { path: null, error: "Geen bestand geselecteerd." };
  return saveMediaUpload(file);
}