import { writeFileSync } from 'fs';
import { Readable } from 'stream';
import { promisify } from 'util';

import axios from 'axios';
import * as CallableInstance from 'callable-instance';
import { XmlEntities } from 'html-entities';
import { PNG } from 'pngjs';
import * as puppeteer from 'playwright';
import * as sharp from 'sharp';
import * as temp from 'temp';

import { getLogger } from './loggers';
import { Message } from './koishi';
import { chainPromises } from './utils';
import { linkBuilder, MediaItem, LazyMediaItem, WebshotHelpers } from './twitter';

const xmlEntities = new XmlEntities();

const ZHType = (type: string) => new class extends String {
  public type = super.toString();
  public toString = () => `[${super.toString()}]`;
}(type);

const typeInZH = {
  photo: ZHType('图片'),
  video: ZHType('视频'),
};

const logger = getLogger('webshot');

export type Page = puppeteer.Page;
export type Cookies = puppeteer.Cookie[];

class Webshot extends CallableInstance<[LazyMediaItem[], (...args) => void, number], Promise<void>> {

  private browser: puppeteer.Browser;
  private mode: number;
  private wsUrl: string;
  private getCookies: () => Cookies;

  constructor(
    wsUrl: string, mode: number,
    getCookies: () => Cookies,
    onready: (doOnNewPage?: typeof Webshot.prototype.performOnNewPage) => void
  ) {
    super('webshot');
    // tslint:disable-next-line: no-conditional-assignment
    // eslint-disable-next-line no-cond-assign
    if (this.mode = mode) {
      if (onready) onready();
    } else {
      this.getCookies = getCookies;
      this.wsUrl = wsUrl;
      this.connect(() => onready && onready(this.performOnNewPage));
    }
  }

  private connect = (onready?: (...args) => void): Promise<void> =>
    axios.get<{[key in 'chromium' | 'firefox' | 'webkit']?: string}>(this.wsUrl)
      .then(res => {
        logger.info(`received websocket endpoint: ${JSON.stringify(res.data)}`);
        const browserType = Object.keys(res.data)[0] as keyof typeof res.data;
        return (puppeteer[browserType] as puppeteer.BrowserType<puppeteer.Browser>)
          .connect({wsEndpoint: res.data[browserType]});
      })
      .then(browser => this.browser = browser)
      .then(() => {
        logger.info('launched puppeteer browser');
        if (onready) return onready();
      })
      .catch(error => this.reconnect(error, onready));

  private reconnect = (error, onready?: (...args) => void) => {
    logger.error(`connection error, reason: ${error}`);
    logger.warn('trying to reconnect in 2.5s...');
    return promisify(setTimeout)(2500)
      .then(() => this.connect(onready));
  };

  private performOnNewPage = <T>(action: (page: Page) => T | PromiseLike<T>, zoomFactor = 2, reconnectOnError = true) =>
    this.browser.newPage({
      bypassCSP: true,
      deviceScaleFactor: zoomFactor,
      locale: 'ja-JP',
      timezoneId: 'Asia/Tokyo',
      userAgent: 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36',
    }).then(action)
      .catch(error => {
        if (reconnectOnError) {
          return this.reconnect(error)
            .then((): Promise<T> => this.performOnNewPage(action, zoomFactor, reconnectOnError));
        }
        throw error;
      });

  private renderWebshot = (
    url: string, height: number, webshotDelay: number,
    ...morePostProcessings: ((page: Page) => Promise<any>)[]
  ): Promise<string> => {
    temp.track();
    const jpeg = (data: Readable) => data.pipe(sharp()).jpeg({quality: 90, trellisQuantisation: true});
    const sharpToFile = (pic: sharp.Sharp) => new Promise<string>(resolve => {
      const webshotTempFilePath = temp.path({suffix: '.jpg'});
      pic.toFile(webshotTempFilePath).then(() => resolve(`file://${webshotTempFilePath}`));
    });
    const promise = new Promise<{ path: string, boundary: null | number }>((resolve, reject) => {
      const width = 720;
      const zoomFactor = 2;
      logger.info(`shooting ${width}*${height} webshot for ${url}`);
      this.performOnNewPage(
        page => {
          const startTime = new Date().getTime();
          const getTimerTime = () => new Date().getTime() - startTime;
          const getTimeout = () => WebshotHelpers.isWaitingForLogin ? 0 : Math.max(500, webshotDelay - getTimerTime());
          page.setViewportSize({
            width: width / zoomFactor,
            height: height / zoomFactor,
          }).then(() => page.context().addCookies(this.getCookies()))
            .then(() => page.goto(url, {waitUntil: 'load', timeout: getTimeout()}))
            .then(() => WebshotHelpers.handleCookieConsent(page))
            .then(() =>
              (<T>(next: () => Promise<T>) => Promise.race([
                WebshotHelpers.handleLogin(page)
                  .then(() => page.goto(url, {waitUntil: 'load', timeout: getTimeout()}))
                  .then(next),
                next(),
              ]))(() => promisify(setTimeout)(2000).then(() => page.waitForSelector('article', {timeout: getTimeout()})))
            )
            .catch((err: Error): Promise<puppeteer.ElementHandle<Element> | null> => {
              if (err.name !== 'TimeoutError') throw err;
              logger.warn(`navigation timed out at ${getTimerTime()} ms`);
              return null;
            })
            // hide header, footer, "more options" button, like and share count, avatar stories/live indicator
            // person tags, carousel navigator, 2nd avatar, and comments; adjust layout for center alignment
            .then(() => page.addStyleTag({content:
              'nav,footer,main>*>*+*,header+div,header~div>div>div+div,main button,canvas,main section,main section+div>ul>:not(div),' +
              'main section+div>ul>div [role="button"],header~div [tabindex="0"]>*>[tabindex="-1"]~div{display:none!important} ' +
              'section+div{overflow:hidden} section+*>*{position:relative!important} article{border-bottom:1px solid!important} ' +
              'main section+div>ul>div>li{padding:6px 2px 12px!important}',
            }))
            .then(() => page.addStyleTag({
              content: '*{font-family:-apple-system,".Helvetica Neue DeskInterface",Hiragino Sans,Hiragino Sans GB,sans-serif!important}',
            }))
            // display absolute date and time and remove "comment limited" notice
            .then(() => page.evaluate(() => {
              let time: HTMLTimeElement;
              time = document.querySelector('div>div>time');
              if (time) time.parentElement.parentElement.style.display = 'none';
              time = document.querySelector('main section~div>a>time');
              if (time) {
                time.innerHTML = time.title + ' ' + new Date(time.dateTime).toLocaleTimeString().slice(0, -3);
                time.parentElement.parentElement.style.margin = '-24px 2px 12px';
                const element = time.parentElement.parentElement.nextElementSibling as HTMLElement;
                if (element) element.style.display = 'none';
              }
            }))
            .then(() => chainPromises(morePostProcessings.map(func => () => func(page))))
            .then(() => promisify(setTimeout)(getTimeout()))
            .then(() => page.screenshot())
            .then(screenshot => {
              new PNG({
                filterType: 4,
                deflateLevel: 0,
              }).on('parsed', function () {
                const idx = (x: number, y: number) => (this.width * y + x) << 2;
                let boundary: number = null;
                for (let y = this.height - 1; y > this.height - 3840; y -= zoomFactor) {
                  if (
                    this.data[idx(zoomFactor, y)] <= 38 &&
                    this.data[idx(zoomFactor, y)] === this.data[idx(this.width - zoomFactor, y)] &&
                    this.data[idx(zoomFactor, y + zoomFactor)] === this.data[idx(zoomFactor, y - 2 * zoomFactor)]
                  ) {
                    boundary = y - 1;
                    break;
                  }
                }
                if (boundary !== null) {
                  logger.info(`found boundary at ${boundary}, cropping image`);
                  this.data = this.data.slice(0, idx(this.width, boundary));
                  this.height = boundary;

                  sharpToFile(jpeg(this.pack())).then(path => {
                    logger.info(`finished webshot for ${url}`);
                    resolve({path, boundary});
                  });
                } else if (height >= 8 * 1920) {
                  logger.warn('too large, consider as a bug, returning');
                  sharpToFile(jpeg(this.pack())).then(path => {
                    resolve({path, boundary: 0});
                  });
                } else {
                  logger.info('unable to find boundary, try shooting a larger image');
                  resolve({path: '', boundary});
                }
              }).parse(screenshot);
            })
            .catch(err => {
              if (err instanceof Error && err.name !== 'TimeoutError') throw err;
              logger.error(`error shooting webshot for ${url}, could not load web page of tweet`);
              resolve({path: '', boundary: 0});
            })
            .finally(() => { page.close(); });
        },
        zoomFactor, false)
        .catch(reject);
    });
    return promise.then(data => {
      if (data.boundary === null) {
        return this.renderWebshot(url, height + 3840, webshotDelay, ...morePostProcessings);
      } else return data.path;
    }).catch(error => this.reconnect(error)
      .then(() => this.renderWebshot(url, height, webshotDelay, ...morePostProcessings))
    );
  };

  private fetchMedia = (url: string): Promise<string> => new Promise<ArrayBuffer>((resolve, reject) => {
    logger.info(`fetching ${url}`);
    axios({
      method: 'get',
      url,
      responseType: 'arraybuffer',
      timeout: 150000,
    }).then(res => {
      if (res.status === 200) {
        logger.info(`successfully fetched ${url}`);
        resolve(res.data);
      } else {
        logger.error(`failed to fetch ${url}: ${res.status}`);
        reject();
      }
    }).catch (err => {
      logger.error(`failed to fetch ${url}: ${err instanceof Error ? err.message : err}`);
      reject();
    });
  }).then(data =>
    (ext => {
      const mediaTempFilePath = temp.path({suffix: `.${ext}`});
      writeFileSync(mediaTempFilePath, Buffer.from(data));
      const path = `file://${mediaTempFilePath}`;
      switch (ext) {
        case 'jpg':
        case 'png':
          return Message.Image(path);
        case 'mp4':
          return Message.Video(path);
      }
      logger.warn('unable to find MIME type of fetched media, failing this fetch');
      throw Error();
    })(/\/.*\.(.+?)\?/.exec(url)[1])
  );

  public webshot(
    lazyMediaItems: LazyMediaItem[],
    callback: (msgs: string, text: string, author: string) => void,
    webshotDelay: number
  ): Promise<void> {
    let grandPromise = Promise.resolve();
    // eslint-disable-next-line @typescript-eslint/no-misused-promises
    lazyMediaItems.forEach(lazyItem => grandPromise = grandPromise.then(lazyItem.item).then(item => {
      let promise = Promise.resolve();
      promise = promise.then(() => {
        logger.info(`working on ${item.user.username}/${item.code}`);
      });
      let messageChain = '';

      // text processing
      const author = `${item.user.full_name} (@${item.user.username}):\n`;
      const text = item.caption?.text || '';
      if (this.mode > 0) messageChain += (author + xmlEntities.decode(text));

      // invoke webshot
      if (this.mode === 0) {
        const url = linkBuilder({postUrlSegment: item.code});
        promise = promise.then(() => this.renderWebshot(url, 3840, webshotDelay, page =>
          // display full name
          page.addStyleTag({content:
            'header>div>div+div{font-size:12px; line-height:15px; padding-top:0!important}' +
            `header>div>div+div::before{content:"${item.user.full_name}"; color:#8e8e8e; font-weight:bold}`,
          })
        ))
          .then(fileurl => {
            if (fileurl) return Message.Image(fileurl);
            return author + text;
          })
          .then(msg => {
            if (msg) messageChain += msg;
          });
      }
      // fetch extra entities
      const type = (mediaItem): keyof typeof typeInZH =>
        (mediaItem as MediaItem).video_versions ? 'video' : 'photo';
      const fetchBestCandidate =(
        candidates: (Partial<typeof item.video_versions[0]> & typeof item.image_versions2.candidates[0])[],
        mediaType: keyof typeof typeInZH
      ) => {
        const url = candidates
          .sort((var1, var2) => var2.width + (var2?.type || 0) - var1.width - (var1?.type || 0))
          .map(variant => variant.url)[0]; // largest media
        const altMessage = `\n[失败的${typeInZH[mediaType].type}：${url}]`;
        return this.fetchMedia(url)
          .catch(error => {
            logger.warn('unable to fetch media, sending plain text instead...');
            return altMessage;
          })
          .then(msg => { messageChain += msg; });
      };
      // tslint:disable-next-line: curly
      // eslint-disable-next-line curly
      if (1 - this.mode % 2) promise = promise.then(() => {
        if (item.carousel_media) {
          return chainPromises(item.carousel_media.map(carouselItem =>
            () => fetchBestCandidate(
              (carouselItem as unknown as MediaItem).video_versions || 
              carouselItem.image_versions2.candidates,
              type(carouselItem)
            )
          ));
        } else if (item.video_versions) {
          return fetchBestCandidate(item.video_versions, type(item));
        } else if (item.image_versions2) {
          return fetchBestCandidate(item.image_versions2.candidates, type(item));
        }
      });
      promise.then(() => {
        logger.info(`done working on ${item.user.username}/${item.code}, message chain:`);
        logger.info(JSON.stringify(Message.ellipseBase64(messageChain)));
        callback(messageChain, xmlEntities.decode(text), author);
      });
      return promise;
    }));
    return grandPromise;
  }
}

export default Webshot;