import multihash from "multihashes";
import querystring from "querystring";

let proxyBase = "https://steemitimages.com";

export function setProxyBase(p: string): void {
  proxyBase = p;
}

export function extractPHash(url: string): string | null {
  if (url.startsWith(`${proxyBase}/p/`)) {
    const [hash] = url.split("/p/")[1].split("?");
    return hash.replace(/.webp/, "").replace(/.png/, "");
  }
  return null;
}

export function getLatestUrl(str: string): string {
  const [last] = [
    ...str
      .replace(/https?:\/\//g, "\n$&")
      .trim()
      .split("\n"),
  ].reverse();
  return last;
}

export function proxifyImageSrc(
  url?: string,
  width = 0,
  height = 0,
  format = "match"
): string {
  if (!url || typeof url !== "string") {
    return "";
  }

  // skip images already proxified with images.hive.blog
  if (
    url.indexOf("https://images.hive.blog/") === 0 &&
    url.indexOf("https://images.hive.blog/D") !== 0
  ) {
    return url.replace("https://images.hive.blog", proxyBase);
  }

  if (
    url.indexOf("https://steemitimages.com/") === 0 &&
    url.indexOf("https://steemitimages.com/D") !== 0
  ) {
    return url.replace("https://steemitimages.com", proxyBase);
  }

  const realUrl = getLatestUrl(url);
  const pHash = extractPHash(realUrl);

  const options: Record<string, string | number> = {
    format,
    mode: "fit",
  };

  if (width > 0) {
    options.width = width;
  }

  if (height > 0) {
    options.height = height;
  }

  const qs = querystring.stringify(options);

  if (pHash) {
    return `${proxyBase}/p/${pHash}${
      format === "webp" ? ".webp" : ".png"
    }?${qs}`;
  }

  const b58url = multihash.toB58String(Buffer.from(realUrl.toString()));

  // return `${proxyBase}/p/${b58url}${format==='webp'?'.webp':'.png'}?${qs}`
  return `https://steemitimages.com/${width}x${height}/${url}`;
}