import cheerio from 'cheerio';
import got, { Response } from 'got';
import { HttpsProxyAgent, HttpProxyAgent } from 'hpagent';
import { globalAgent as httpGlobalAgent } from 'http';
import { globalAgent as httpsGlobalAgent } from 'https';

import CONFIG from './config';

const GALLERY_JSON_REGEX = /window\.postDataJSON=(".*")$/;

const agent = {
  http: CONFIG.http_proxy 
    ? new HttpProxyAgent({
        keepAlive: true,
        keepAliveMsecs: 1000,
        maxSockets: 256,
        maxFreeSockets: 256,
        scheduling: 'lifo',
        proxy: CONFIG.http_proxy,
      })
    : httpGlobalAgent,
  https: CONFIG.https_proxy 
    ? new HttpsProxyAgent({
        keepAlive: true,
        keepAliveMsecs: 1000,
        maxSockets: 256,
        maxFreeSockets: 256,
        scheduling: 'lifo',
        proxy: CONFIG.https_proxy,
      })
    : httpsGlobalAgent
};

export const fetchComments = async (galleryID: string): Promise<Comment[]> => {
  // https://api.imgur.com/comment/v1/comments?client_id=${CLIENT_ID}%5Bpost%5D=eq%3Ag1bk7CB&include=account%2Cadconfig&per_page=30&sort=best
  const response = await got(`https://api.imgur.com/comment/v1/comments?client_id=${CONFIG.imgur_client_id}&filter%5Bpost%5D=eq%3A${galleryID}&include=account%2Cadconfig&per_page=30&sort=best`);
  return JSON.parse(response.body).data;
}

export const fetchGallery = async (galleryID: string): Promise<Gallery> => {
  // https://imgur.com/gallery/g1bk7CB
  const response = await got(`https://imgur.com/gallery/${galleryID}`, { agent });
  const $ = cheerio.load(response.body);
  const postDataScript = $('head script:first-of-type').html();
  if (!postDataScript) {
    throw new Error('Could not find gallery data');
  }
  const postDataMatches = postDataScript.match(GALLERY_JSON_REGEX);
  if (!postDataMatches || postDataMatches.length < 2) {
    throw new Error('Could not parse gallery data');
  }
  const postData = JSON.parse(JSON.parse(postDataMatches[1]));
  return postData;
};

export const fetchAlbumURL = async (albumID: string): Promise<string> => {
  // https://imgur.com/a/DfEsrAB
  const response = await got(`https://imgur.com/a/${albumID}`, { agent });
  const $ = cheerio.load(response.body);
  const url = $('head meta[property="og:image"]').attr('content')?.replace(/\/\?.*$/, '');
  if (!url) {
    throw new Error('Could not read image url');
  }
  return url;
};

export const fetchMedia = async (filename: string): Promise<Response<string>> =>
  await got(`https://i.imgur.com/${filename}`, { agent });