import { hash } from "@lib/hash.ts";
import * as cache from "@lib/cache/cache.ts";

type ImageCacheOptions = {
  url: string;
  width: number;
  height: number;
  mediaType?: string;
};

const CACHE_KEY = "images";

function getCacheKey({ url: _url, width, height }: ImageCacheOptions) {
  const url = new URL(_url);

  return `${CACHE_KEY}/${url.hostname}/${url.pathname}/${width}/${height}`
    .replace(
      "//",
      "/",
    );
}

export async function getImage({ url, width, height }: ImageCacheOptions) {
  const cacheKey = getCacheKey({ url, width, height });

  const pointerCacheRaw = await cache.get<string>(cacheKey);
  if (!pointerCacheRaw) return;

  const pointerCache = typeof pointerCacheRaw === "string"
    ? JSON.parse(pointerCacheRaw)
    : pointerCacheRaw;

  const imageContent = await cache.get(pointerCache.id, true);
  if (!imageContent) return;

  return {
    ...pointerCache,
    buffer: imageContent,
  };
}

export async function setImage(
  buffer: Uint8Array,
  { url, width, height, mediaType }: ImageCacheOptions,
) {
  const clone = new Uint8Array(buffer);

  const cacheKey = getCacheKey({ url, width, height });
  const pointerId = await hash(cacheKey);

  await cache.set(pointerId, clone);
  cache.expire(pointerId, 60 * 10);
  cache.expire(cacheKey, 60 * 10);

  await cache.set(
    cacheKey,
    JSON.stringify({
      id: pointerId,
      url,
      width,
      height,
      mediaType,
    }),
  );
}