/* ============================================================================
   CMS ACCESS - server only
   ----------------------------------------------------------------------------
   `.server.ts`, so the bundler keeps this (and the Strapi token behind it) out
   of the browser build entirely. Call it from a `loader` / `action`.

   Everything here is deliberately forgiving. The CMS is empty today - and in
   development it is often not running at all - so a page must render its
   approved draft copy rather than a 500 when Strapi answers 404, times out or
   refuses the connection. `loadSingle` / `loadMany` therefore turn any
   transport- or Strapi-level failure into `null` / `[]` and log it once,
   server-side. A genuinely missing *entity* on a $slug route is a different
   thing: use `requireEntity()` from ~/lib/strapi for that, so the root
   ErrorBoundary can render the localised 404.
   ========================================================================= */

import {
  getMany,
  getSingle,
  isStrapiError,
  mediaAlt,
  mediaFormatUrl,
  type StrapiMedia,
  type StrapiQuery,
} from "~/lib/strapi";

import type { CmsPartner } from "./cms-types";

/** A picture, resolved to absolute URLs at load time. */
export interface ResolvedImage {
  readonly src: string;
  readonly alt: string;
  readonly width?: number;
  readonly height?: number;
}

/** A partner, flattened to exactly what the partner grid renders. */
export interface ResolvedPartner {
  readonly id: string;
  readonly name: string;
  readonly website?: string;
  readonly logo?: ResolvedImage;
}

function warn(resource: string, error: unknown): void {
  const reason = isStrapiError(error)
    ? `${error.status || "network"} ${error.message}`
    : String(error);
  console.warn(`[cms] "${resource}" is unavailable - rendering fallback copy (${reason})`);
}

/**
 * One entry of a single type, or `null` when the CMS has none / is unreachable.
 */
export async function loadSingle<T>(
  resource: string,
  query?: StrapiQuery,
): Promise<T | null> {
  try {
    return await getSingle<T>(resource, query);
  } catch (error) {
    warn(resource, error);
    return null;
  }
}

/** A collection page, or `[]` when the CMS has none / is unreachable. */
export async function loadMany<T>(
  resource: string,
  query?: StrapiQuery,
): Promise<T[]> {
  try {
    const { data } = await getMany<T>(resource, query);
    return data;
  } catch (error) {
    warn(resource, error);
    return [];
  }
}

/**
 * A Strapi media entity as a plain, absolute-URL image.
 *
 * `format` picks the responsive derivative Strapi generated; it silently falls
 * back to the original when that derivative does not exist (small uploads).
 * `alt` comes from the CMS and stays "" when the editor left it empty, which is
 * the correct markup for a decorative image.
 */
export function toImage(
  media: StrapiMedia | null | undefined,
  format: "thumbnail" | "small" | "medium" | "large" = "large",
): ResolvedImage | undefined {
  if (!media) return undefined;

  const src = mediaFormatUrl(media, format);
  if (!src) return undefined;

  return {
    src,
    alt: mediaAlt(media),
    ...(media.width ? { width: media.width } : {}),
    ...(media.height ? { height: media.height } : {}),
  };
}

/** Flatten a populated partner relation for the grid. */
export function toPartner(partner: CmsPartner): ResolvedPartner {
  return {
    id: partner.documentId ?? String(partner.id),
    name: partner.name,
    ...(partner.website ? { website: partner.website } : {}),
    ...(toImage(partner.logo ?? partner.logoDark, "small")
      ? { logo: toImage(partner.logo ?? partner.logoDark, "small") }
      : {}),
  };
}

/**
 * A Strapi `json` field authored as a list of strings ("Dialogue",
 * "Inclusion", ...). Anything else in the field is ignored rather than thrown
 * over, because an editor can put arbitrary JSON there.
 */
export function toStringList(value: unknown): string[] {
  if (!Array.isArray(value)) return [];
  return value.filter((item): item is string => typeof item === "string" && item.trim() !== "");
}

/** Drop `null`/`undefined` and empty arrays in one expression. */
export function list<T>(value: readonly T[] | null | undefined): T[] {
  return value ? [...value] : [];
}