gocqhttp-twitter-bot/src/webshot.ts

import axios from 'axios';
import * as CallableInstance from 'callable-instance';
import { createWriteStream, existsSync, mkdirSync } from 'fs';
import { XmlEntities } from 'html-entities';
import { MessageType } from 'mirai-ts';
import Message from 'mirai-ts/dist/message';
import { PNG } from 'pngjs';
import * as puppeteer from 'puppeteer';
import { Browser } from 'puppeteer';
import { Stream } from 'stream';

import { getLogger } from './loggers';

const writeOutTo = async (path: string, data: PNG | Stream) => {
  await new Promise(resolve => data.pipe(createWriteStream(path)).on('close', resolve));
  return path;
};

const xmlEntities = new XmlEntities();

const typeInZH = {
  photo: '[图片]',
  video: '[视频]',
  animated_gif: '[GIF]',
};

const logger = getLogger('webshot');

const mkdirP = dir => { if (!existsSync(dir)) mkdirSync(dir, {recursive: true}); };
const baseName = path => path.split(/[/\\]/).slice(-1)[0];

type MessageChain = MessageType.MessageChain;

class Webshot extends CallableInstance<[number], Promise<void>> {

  private browser: Browser;
  private outDir: string;
  private mode: number;

  constructor(outDir: string, mode: number, onready?: () => any) {
    super('webshot');
    mkdirP(this.outDir = outDir);
    // tslint:disable-next-line: no-conditional-assignment
    if (this.mode = mode) {
      onready();
    } else {
      puppeteer.launch({
        args: [
          '--no-sandbox',
          '--disable-setuid-sandbox',
          '--disable-dev-shm-usage',
          '--disable-accelerated-2d-canvas',
          '--no-first-run',
          '--no-zygote',
          '--single-process', // <- this one doesn't works in Windows
          '--disable-gpu',
          '--lang=ja-JP,ja',
        ]})
      .then(browser => this.browser = browser)
      .then(() => {
        logger.info('launched puppeteer browser');
        if (onready) onready();
      });
    }
  }

  private renderWebshot = (url: string, height: number, webshotDelay: number): Promise<string> => {
    const writeOutPic = (pic: PNG) => writeOutTo(`${this.outDir}/${url.replace(/[:\/]/g, '_')}.png`, pic);
    const promise = new Promise<{ data: string, boundary: null | number }>(resolve => {
      const width = 600;
      logger.info(`shooting ${width}*${height} webshot for ${url}`);
      this.browser.newPage()
        .then(page => {
          page.setUserAgent('Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36')
            .then(() => page.setViewport({
              width,
              height,
              isMobile: true,
            }))
            .then(() => page.setBypassCSP(true))
            .then(() => page.goto(url, {waitUntil: 'load', timeout: 150000}))
            // hide header, "more options" button, like and retweet count
            .then(() => page.addStyleTag({
              content: 'header{display:none!important}path[d=\'M20.207 7.043a1 1 0 0 0-1.414 0L12 13.836 5.207 7.043a1 1 0 0 0-1.414 1.414l7.5 7.5a.996.996 0 0 0 1.414 0l7.5-7.5a1 1 0 0 0 0-1.414z\'],div[role=\'button\']{display: none;}',
            }))
            .then(() => page.waitFor(webshotDelay))
            .then(() => page.addScriptTag({
              content: 'document.documentElement.scrollTop=0;',
            }))
            .then(() => page.screenshot())
            .then(screenshot => {
              new PNG({
                filterType: 4,
              }).on('parsed', function () {
                // remove comment area
                let boundary = null;
                let x = 0;
                for (let y = 0; y < this.height; y++) {
                  const idx = (this.width * y + x) << 2;
                  if (this.data[idx] !== 255) {
                    boundary = y;
                    break;
                  }
                }
                if (boundary !== null) {
                  logger.info(`found boundary at ${boundary}, cropping image`);
                  this.data = this.data.slice(0, (this.width * boundary) << 2);
                  this.height = boundary;

                  boundary = null;
                  x = Math.floor(this.width / 2);
                  let flag = false;
                  let cnt = 0;
                  for (let y = this.height - 1; y >= 0; y--) {
                    const idx = (this.width * y + x) << 2;
                    if ((this.data[idx] === 255) === flag) {
                      cnt++;
                      flag = !flag;
                    } else continue;

                    // line above the "comment", "retweet", "like", "share" button row
                    if (cnt === 6) {
                      boundary = y + 1;
                    }

                    // if there are a "retweet" count and "like" count row, this will be the line above it
                    if (cnt === 8) {
                      const b = y + 1;
                      if (this.height - b <= 200) boundary = b;
                      break;
                    }
                  }
                  if (boundary != null) {
                    logger.info(`found boundary at ${boundary}, trimming image`);
                    this.data = this.data.slice(0, (this.width * boundary) << 2);
                    this.height = boundary;
                  }

                  writeOutPic(this.pack()).then(data => {
                    logger.info(`finished webshot for ${url}`);
                    resolve({data, boundary});
                  });
                } else if (height >= 8 * 1920) {
                  logger.warn('too large, consider as a bug, returning');
                  writeOutPic(this.pack()).then(data => {
                    resolve({data, boundary: 0});
                  });
                } else {
                  logger.info('unable to find boundary, try shooting a larger image');
                  resolve({data: '', boundary});
                }
              }).parse(screenshot);
            })
            .then(() => page.close());
        });
    });
    return promise.then(data => {
      if (data.boundary === null) return this.renderWebshot(url, height + 1920, webshotDelay);
      else return data.data;
    });
  }

  private fetchImage = (url: string, tag: string): Promise<string> =>
    new Promise<Stream>(resolve => {
      logger.info(`fetching ${url}`);
      axios({
        method: 'get',
        url,
        responseType: 'stream',
      }).then(res => {
        if (res.status === 200) {
            logger.info(`successfully fetched ${url}`);
            resolve(res.data);
        } else {
          logger.error(`failed to fetch ${url}: ${res.status}`);
          resolve();
        }
      }).catch (err => {
        logger.error(`failed to fetch ${url}: ${err.message}`);
        resolve();
      });
    }).then(data => writeOutTo(`${this.outDir}/${tag}${baseName(url)}`, data))

  public webshot(
    tweets,
    callback: (msgs: MessageChain, text: string, author: string) => void,
    webshotDelay: number
  ): Promise<void> {
    let promise = new Promise<void>(resolve => {
      resolve();
    });
    tweets.forEach(twi => {
      promise = promise.then(() => {
        logger.info(`working on ${twi.user.screen_name}/${twi.id_str}`);
      });
      const originTwi = twi.retweeted_status || twi;
      const messageChain: MessageChain = [];

      // text processing
      let author = `${twi.user.name} (@${twi.user.screen_name}):\n`;
      if (twi.retweeted_status) author += `RT @${twi.retweeted_status.user.screen_name}: `;

      let text = originTwi.full_text;

      promise = promise.then(() => {
        if (originTwi.entities && originTwi.entities.urls && originTwi.entities.urls.length) {
          originTwi.entities.urls.forEach(url => {
            text = text.replace(new RegExp(url.url, 'gm'), url.expanded_url);
          });
        }
        if (originTwi.extended_entities) {
          originTwi.extended_entities.media.forEach(media => {
            text = text.replace(new RegExp(media.url, 'gm'), this.mode === 1 ? typeInZH[media.type] : '');
          });
        }
        if (this.mode > 0) messageChain.push(Message.Plain(author + xmlEntities.decode(text)));
      });

      // invoke webshot
      if (this.mode === 0) {
        const url = `https://mobile.twitter.com/${twi.user.screen_name}/status/${twi.id_str}`;
        promise = promise.then(() => this.renderWebshot(url, 1920, webshotDelay))
          .then(webshotFilePath => {
            if (webshotFilePath) messageChain.push(Message.Image('', '', baseName(webshotFilePath)));
          });

      // fetch extra images
      } else if (1 - this.mode % 2) {
        if (originTwi.extended_entities) {
          promise = promise.then(() => originTwi.extended_entities.media.forEach(media => {
            this.fetchImage(media.media_url_https, `${twi.user.screen_name}-${twi.id_str}--`)
            .then(path =>
              messageChain.push(Message.Image('', '', baseName(path)))
            );
          }));
        }

      // append URLs, if any
      } else if (this.mode === 0) {
        if (originTwi.entities && originTwi.entities.urls && originTwi.entities.urls.length) {
          promise = promise.then(() => {
            const urls = originTwi.entities.urls
              .filter(urlObj => urlObj.indices[0] < originTwi.display_text_range[1])
              .map(urlObj => urlObj.expanded_url);
            if (urls.length) {
              messageChain.push(Message.Plain(urls.join('\n')));
            }
          });
        }
      }
      promise.then(() => {
        logger.info(`done working on ${twi.user.screen_name}/${twi.id_str}, message chain:`);
        logger.info(JSON.stringify(messageChain));
        callback(messageChain, text, author);
      });
    });
    return promise;
  }
}

export default Webshot;