import { appLocales } from "../i18n/routing";
import type { SeoSettings } from "./seo-settings";
import type { SiteSettings, SiteSettingsMediaBindings } from "./site-settings";

export type SeoCheckStatus = "ok" | "warn" | "error";

export type SeoCheck = {
  id: string;
  label: string;
  status: SeoCheckStatus;
  detail: string;
};

/**
 * Pure readiness checklist shown on the admin SEO page. Every input comes from
 * the caller so the same function is testable without a database.
 */
export function buildSeoChecklist(input: {
  seo: SeoSettings;
  settings: SiteSettings;
  bindings: SiteSettingsMediaBindings;
  maintenanceEnabled: boolean;
  publishedProjectCount: number;
  sitemapEntryCount: number;
  siteUrl: string;
}): SeoCheck[] {
  const { seo, settings, bindings, maintenanceEnabled, publishedProjectCount, sitemapEntryCount, siteUrl } = input;
  const checks: SeoCheck[] = [];

  checks.push({
    id: "indexing",
    label: "Indexierung",
    status: seo.allowIndexing && !maintenanceEnabled ? "ok" : "error",
    detail: maintenanceEnabled
      ? "Wartungsmodus aktiv: robots.txt sperrt alles, Sitemap ist leer."
      : seo.allowIndexing
        ? "Suchmaschinen duerfen die Seite indexieren."
        : "Indexierung ist deaktiviert (noindex + robots disallow).",
  });

  checks.push({
    id: "site-url",
    label: "Oeffentliche URL",
    status: /^https:\/\//.test(siteUrl) && !/localhost|127\.0\.0\.1/.test(siteUrl) ? "ok" : "warn",
    detail: `Canonical Basis: ${siteUrl}`,
  });

  for (const locale of appLocales) {
    const localeSettings = settings.locales[locale];
    const descriptionLength = localeSettings.siteDescription.length;
    const status: SeoCheckStatus =
      descriptionLength === 0 ? "error" : descriptionLength < 50 || descriptionLength > 160 ? "warn" : "ok";

    checks.push({
      id: `description-${locale}`,
      label: `Meta Description (${locale.toUpperCase()})`,
      status,
      detail:
        descriptionLength === 0
          ? "Fehlt. Wird unter Settings > Localization gepflegt."
          : `${descriptionLength} Zeichen (empfohlen 50-160).`,
    });
  }

  checks.push({
    id: "og-image",
    label: "Standard Share Bild (OG)",
    status: bindings.defaultOgImage ? "ok" : "warn",
    detail: bindings.defaultOgImage
      ? "Gesetzt. Projekte nutzen ihr Cover, alle anderen Seiten dieses Bild."
      : "Nicht gesetzt. Links ohne Vorschaubild. Unter Settings > Brand pflegen.",
  });

  checks.push({
    id: "favicon",
    label: "Favicon",
    status: bindings.favicon ? "ok" : "warn",
    detail: bindings.favicon ? "Gesetzt." : "Nicht gesetzt (Fallback-Icon wird generiert).",
  });

  checks.push({
    id: "verification",
    label: "Search Console / Bing",
    status: seo.googleSiteVerification || seo.bingSiteVerification ? "ok" : "warn",
    detail:
      seo.googleSiteVerification || seo.bingSiteVerification
        ? "Verification Meta Tags werden ausgegeben."
        : "Kein Verification Code hinterlegt.",
  });

  checks.push({
    id: "structured-data",
    label: "Strukturierte Daten (JSON-LD)",
    status: seo.structuredDataName || settings.locales[settings.defaultLocale].siteName ? "ok" : "warn",
    detail: `${seo.structuredDataType} + WebSite auf allen Seiten, CreativeWork pro Projekt.`,
  });

  checks.push({
    id: "projects",
    label: "Veroeffentlichte Projekte",
    status: publishedProjectCount > 0 ? "ok" : "warn",
    detail:
      publishedProjectCount > 0
        ? `${publishedProjectCount} Projekt(e) in der Sitemap.`
        : "Noch kein Projekt veroeffentlicht. Portfolio-Seiten sind leer.",
  });

  checks.push({
    id: "sitemap",
    label: "Sitemap",
    status: sitemapEntryCount > 0 ? "ok" : maintenanceEnabled || !seo.allowIndexing ? "warn" : "error",
    detail: `${sitemapEntryCount} URL(s) in /sitemap.xml (alle Sprachen, mit hreflang).`,
  });

  return checks;
}

export function summarizeSeoChecklist(checks: SeoCheck[]) {
  return {
    ok: checks.filter((check) => check.status === "ok").length,
    warn: checks.filter((check) => check.status === "warn").length,
    error: checks.filter((check) => check.status === "error").length,
  };
}