const Scraper = require('../helpers/scraper');
const cheerio = require('cheerio');
const path = require('path');
const jsonfile = require('jsonfile');
const logger = require('log4js').getLogger('DK');
logger.level = process.env.LOGGER_LEVEL || 'warn';

class DKScrape extends Scraper {

  constructor(checkForLock = true) {
    super();
    this.id = 'DK';

    this.on('done', () => {
      this._done();
    });

    this.run = this._throttle(async () => {
      await this.__run();
    }, 5000);

    if (checkForLock) 
      this._checkLock().then((l) => {
        if(l)
          this.run();
      });

    this.on('error', (err) => {
      logger.error('Error catcher!!', err);
    });
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async processNewPage() {
    // give the page a few seconds to settle
    await this._randomWait(this.page, 3, 5);

    const currentPage = await this.page.evaluate(() => document);

    const search = currentPage.location.search;

    switch (currentPage.location.pathname) {

      case '/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-database.aspx':
        await this.handleStartPage();
        break;
      case '/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-soegning.aspx':
        await this.handleSearchResults(search);
        break;

      case '/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-vis-virksomhed.aspx':
      case '/da/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-vis-virksomhed.aspx':
      case '/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-vis-virksomhed.aspx':
        // these are all the same page, just in Danish, Danish and English
        this.processCoporation();
        break;
      default:

        await this._uploadError();
        throw new Error(`Unknown page: ${currentPage.location.href}`);

    }
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async handleStartPage() {
    if (this.mode === 0)
      await this._findAndClick('ul li a', 'Payment institutions', 'http://vut.finanstilsynet.dk/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-soegning.aspx?aid=Payment+services+area&ctid=Payment+institutions');

    if (this.mode === 1)
      await this._findAndClick('ul li a', 'Electronic money institutions', 'http://vut.finanstilsynet.dk/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-soegning.aspx?aid=Payment+services+area&ctid=Electronic+money+institutions');

    if (this.mode === 2) {
      logger.info('Processing complete');
      this.done();
    }
  }

  /**
   *
   * @returns {Promise<Error>}
   */
  async processCoporation() {
    await this._randomWait(this.page, 3, 5);

    const body = await this.page.evaluate(() => document.documentElement.outerHTML);
    const $ = cheerio.load(body);

    const h2 = $('h2').eq(0).text();
    // Virksomhedsoplysninger
    // Company information

    if (h2 === 'Virksomhedsoplysninger') {
      logger.warn('Not in English, trying to switch language...');
      await this._findAndClick('#mainform > div.header > ul > li.ln > a');
    }
    else if (h2 === 'Company information') {
      const noWhiteSpace = /\W/g;
      let ssName;

      if (this.mode === 0)
        ssName = this.paymentServices.links[this.paymentServices.step].innerText.replace(noWhiteSpace, '_');
      else
        ssName = this.emoneyServices.links[this.emoneyServices.step].innerText.replace(noWhiteSpace, '_');

      await this.page._client.send('Page.setDownloadBehavior', { 'behavior': 'allow', 'downloadPath': this.path });

      this._makeScreenshotV2(this.page, `${this.path}/${ssName}`, null);

      logger.debug('Processing:', this.paymentServices.links[this.paymentServices.step]);

      const fields = await this.extractData(body);

      jsonfile.writeFileSync(`${this.path}/${ssName}.json`, fields);
      await this.downloadExcel();

      if (this.mode === 0)
        this.paymentServices.step += 1;
      else
        this.emoneyServices.step += 1;

      await this._randomWait(this.page, 10, 15);

      // This should take us back to the search result list

      await this._findAndClick('#divContentWidthScr li a', 'To search results');
    }
    else
      return new Error('I do not understand this page...');
  }

  /**
   *
   * @param $block
   * @returns {Promise<Array>}
   */
  async processDataBlock($block) {
    const $ = cheerio.load($block);
    const noWhiteSpace = /\W/g;

    const a = $('tr').map((i, el) => {
      const head = $(el).find('td').first();
      const data = $(el).find('td').next();

      return [head.eq(-1).html().split('</div>')[1].replace(/\n/, '').trim(), data.text()];
    });

    const fields = [];

    for( let step = 0;step < a.length;step = step + 2)
      fields.push([a[step].replace(noWhiteSpace, '_'), a[step + 1]]);

    return fields;
  }

  /**
   *
   * @param body
   * @returns {Promise<{companyInformation: *[], presence: Array}>}
   */
  async extractData(body) {
    const $ = cheerio.load(body);

    const vutDataContainer = $('.vut-data-container');

    const $basicInfo = vutDataContainer.find('#phmain_0_vut_pnl_basic_info table tbody').get();
    const $extendednInfo = vutDataContainer.find('#phmain_0_vut_pnl_extended_info table tbody').get();

    const $presenceInfo = vutDataContainer.find('#phmain_0_vut_pnl_tilstedevaerelser table tbody').get();

    let companyInformation = await this.processDataBlock($basicInfo);
    companyInformation = companyInformation.concat(await this.processDataBlock($extendednInfo));
    const presence = await this.processDataBlock($presenceInfo);

    return { companyInformation, presence };
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async downloadExcel() {
    await this.page._client.send('Page.setDownloadBehavior', { 'behavior': 'allow', 'downloadPath': this.path });
    logger.info('Saving excel into:', this.path);

    await this._findAndClick('#phmain_0_vut_link_button_excel');
  }

  /**
   *
   * @param search
   * @returns {Promise<void>}
   */
  async handleSearchResults(search) {
    switch (search) {

      case '?aid=Payment+services+area&ctid=Payment+institutions':
        if (!this.paymentServices.done)
          await this.handlePaymentServices();
        else
          // Are we not done yet?
          // Restarting the page
          await this.page.goto(this.startPage);

        break;
      case '?aid=Payment+services+area&ctid=Electronic+money+institutions':
        if (!this.emoneyServices.done)
          await this.handleEmoneyServices();
        else
          // Are we not done yet?
          // Restarting the page
          await this.page.goto(this.startPage);

        break;
      case '?restoreSearch=1':
        if (this.mode === 0)
          if (this.paymentServices.items > 0 && !this.paymentServices.done)
            await this.handlePaymentServices();
          else {
            // Are we not done yet?
            // Restarting the page
            await this.page.goto(this.startPage);
          }

        if (this.mode === 1)
          if (this.emoneyServices.items > 0 && !this.emoneyServices.done)
            await this.handleEmoneyServices();

        break;
      default:
        // Menu fell through
        break;

    }
  }

  /**
   *
   * @returns {Promise<Array>}
   */
  async extractLinks() {
    const returnObj = [];
    await this._randomWait(this.page, 3, 5);
    const rows = await this.page.$$('.search-further-data tr a');

    for (const item of rows) {
      const innerText = await this.page.evaluate(el => el.innerText, item);
      const href = await this.page.evaluate(el => el.href, item);
      const id = await this.page.evaluate(el => el.id, item);

      returnObj.push( {
        innerText,
        href,
        id
      });
    }

    return returnObj;
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async handleEmoneyServices() {
    await this._randomWait(this.page, 3, 5);

    await this._findAndClick('#phmain_0_Search1_allBtn', 'SHOW ALL');

    if (!this.emoneyServices.visited)
      if (this.emoneyServices.items === 0) {
        // first visit, Build the list

        this.emoneyServices.links = await this.extractLinks();

        this.emoneyServices.items = this.emoneyServices.links.length;

        this.emoneyServices.visited = true;
      }

    if (this.emoneyServices.visited)

      if (this.emoneyServices.step < this.emoneyServices.items) {
        const nextItem = this.emoneyServices.links[this.emoneyServices.step];

        // Not using an await here. We want to click and exit this page so we don't get tied up

        this._findAndClick(`#${nextItem.id}`, nextItem.innerText);
      }
      else {
        // EMoney services complete, move onto the next service.
        this.emoneyServices.done = true;
        this.mode = 2;
        await this.page.goto(this.startPage);
      }
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async handlePaymentServices() {
    await this._randomWait(this.page, 3, 5);

    await this._findAndClick('#phmain_0_Search1_allBtn', 'SHOW ALL');

    if (!this.paymentServices.visited)
      if (this.paymentServices.items === 0) {
        // first visit, Build the list

        this.paymentServices.links = await this.extractLinks();

        this.paymentServices.items = this.paymentServices.links.length;

        this.paymentServices.visited = true;
      }

    if (this.paymentServices.visited)

      if (this.paymentServices.step < this.paymentServices.items) {
        const nextItem = this.paymentServices.links[this.paymentServices.step];

        // Not using an await here. We want to click and exit this page so we don't get tied up

        this._findAndClick(`#${nextItem.id}`, nextItem.innerText);
      }
      else {
        // Payment services complete, move onto the next service.
        this.paymentServices.done = true;
        this.mode = 1;
        await this.page.goto(this.startPage);
      }
  }

  /**
   *
   * @returns {Promise<void>}
   */
  async start() {
    super._start();
    try {
      // Financial Supervisory Authority
      // Government ministry
      // https://en.wikipedia.org/wiki/Financial_Supervisory_Authority_(Denmark)

      this.mode = 0;

      this.paymentServices = {
        'items': 0,
        'links': {

        },
        'step': 0,
        'visited': false,
        'done' : false
      };

      this.emoneyServices = {
        'items': 0,
        'links': {

        },
        'step': 0,
        'visited': false,
        'done' : false
      };

      this.startPage = 'http://vut.finanstilsynet.dk/en/Tal-og-fakta/Virksomheder-under-tilsyn/VUT-database.aspx';

      this.setPath(path.resolve(`${__dirname }/../artefacts/DK/FSA`));

      await this._doNonRepudiation(false, { 'sslWithPrefix': false }).catch((err) => {
        logger.error(err);
      });

      await this._initBrowser();
      this.page = await this.browser.newPage();

      this.page.on('domcontentloaded', () => {
        this.processNewPage().catch((err) => {
          logger.error('####', err);
          this.emit('done');
        });
      });

      await this.page.tracing.start({ 'path': `${this.path}/trace.json`, 'screenshots':true });

      await this.page.setViewport({ 'width': 1200, 'height': 800 });
      await this.page.goto(this.startPage).catch((err) => {
        logger.error(err);
        this._uploadError();
      });

      await this._randomWait(this.page, 3, 5);
    }
    catch(e) {
      throw Error(e);
    }
  }

  async __run() {
    await this.start();
  }

}

module.exports = DKScrape;