import { load } from "cheerio";
import { AwsClient } from "aws4fetch";

import type { NextRequest } from "next/server";
import { ensureAuth } from "../ensureAuth";

export const runtime = "edge";

export async function POST(request: NextRequest) {
  const r2 = new AwsClient({
    accessKeyId: process.env.R2_ACCESS_KEY_ID,
    secretAccessKey: process.env.R2_SECRET_ACCESS_KEY,
  });

  async function unfurl(url: string) {
    const response = await fetch(url);
    if (response.status >= 400) {
      throw new Error(`Error fetching url: ${response.status}`);
    }
    const contentType = response.headers.get("content-type");
    if (!contentType?.includes("text/html")) {
      throw new Error(`Content-type not right: ${contentType}`);
    }

    const content = await response.text();
    const $ = load(content);

    const og: { [key: string]: string | undefined } = {};
    const twitter: { [key: string]: string | undefined } = {};

    $("meta[property^=og:]").each(
      // @ts-ignore, it just works so why care of type safety if someone has better way go ahead
      (_, el) => (og[$(el).attr("property")!] = $(el).attr("content")),
    );
    $("meta[name^=twitter:]").each(
      // @ts-ignore
      (_, el) => (twitter[$(el).attr("name")!] = $(el).attr("content")),
    );

    const title =
      og["og:title"] ??
      twitter["twitter:title"] ??
      $("title").text() ??
      undefined;
    const description =
      og["og:description"] ??
      twitter["twitter:description"] ??
      $('meta[name="description"]').attr("content") ??
      undefined;
    const image =
      og["og:image:secure_url"] ??
      og["og:image"] ??
      twitter["twitter:image"] ??
      undefined;

    return {
      title,
      description,
      image,
    };
  }

  const d = await ensureAuth(request);
  if (!d) {
    return new Response("Unauthorized", { status: 401 });
  }

  if (
    !process.env.R2_ACCESS_KEY_ID ||
    !process.env.R2_ACCOUNT_ID ||
    !process.env.R2_SECRET_ACCESS_KEY ||
    !process.env.R2_BUCKET_NAME
  ) {
    return new Response(
      "Missing one or more R2 env variables: R2_ENDPOINT, R2_ACCESS_ID, R2_SECRET_KEY, R2_BUCKET_NAME. To get them, go to the R2 console, create and paste keys in a `.dev.vars` file in the root of this project.",
      { status: 500 },
    );
  }

  const website = new URL(request.url).searchParams.get("website");

  if (!website) {
    return new Response("Missing website", { status: 400 });
  }

  const salt = () => Math.floor(Math.random() * 11);
  const encodeWebsite = `${encodeURIComponent(website)}${salt()}`;

  try {
    // this returns the og image, description and title of website
    const response = await unfurl(website);

    if (!response.image) {
      return new Response(JSON.stringify(response));
    }

    if (!process.env.DEV_IMAGES) {
      return new Response("Missing DEV_IMAGES namespace.", { status: 500 });
    }

    const imageUrl = await process.env.DEV_IMAGES!.get(encodeWebsite);
    if (imageUrl) {
      return new Response(
        JSON.stringify({
          image: imageUrl,
          title: response.title,
          description: response.description,
        }),
      );
    }

    const res = await fetch(`${response.image}`);
    const image = await res.blob();

    const url = new URL(
      `https://${process.env.R2_BUCKET_NAME}.${process.env.R2_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    );

    url.pathname = encodeWebsite;
    url.searchParams.set("X-Amz-Expires", "3600");

    const signedPuturl = await r2.sign(
      new Request(url, {
        method: "PUT",
      }),
      {
        aws: { signQuery: true },
      },
    );
    await fetch(signedPuturl.url, {
      method: "PUT",
      body: image,
    });

    await process.env.DEV_IMAGES.put(
      encodeWebsite,
      `${process.env.R2_PUBLIC_BUCKET_ADDRESS}/${encodeWebsite}`,
    );

    return new Response(
      JSON.stringify({
        image: `${process.env.R2_PUBLIC_BUCKET_ADDRESS}/${encodeWebsite}`,
        title: response.title,
        description: response.description,
      }),
    );
  } catch (error) {
    console.log(error);
    return new Response(
      JSON.stringify({
        status: 500,
        error: error,
      }),
    );
  }
}