const Scraper = require('../lib/scraper');
const path = require('path');
const logger = require('log4js').getLogger('RC');

const fs = require('fs');
const dateFormat = require('dateformat');

const _ = require('lodash');
const jsonfile = require('jsonfile');

const Diff = require('text-diff');

const time = require("time-since");
const pug = require('pug');

const PNG = require('pngjs').PNG;
const pixelmatch = require('pixelmatch');


const email = require('smtp-email-sender')({
  'host': 'mail.caliban.io',
  'port': '465',
  'auth': {
    'user': 'aida@caliban.io',
    'pass': 'WaF#E+5am7.)\\csD',
    'type': 'LOGIN' // PLAIN, LOGIN, MD5 etc...
  },
  'secure': 'secure'
});

logger.level = process.env.LOGGER_LEVEL || 'debug';

class ChangeDetection extends Scraper {

  constructor() {
    super();

    this.setID('CD');

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

   pugTest(data, newpath) {
    logger.debug(pug.renderFile(`${newpath}/` + 'pug/email.pug', data));
  }

   async sendSMTP(data, newPath) {
    const now = new Date();

    const attachments = [
      {
        path:data.diffPNG
      }
    ];

    const html = pug.renderFile(`${newPath}/` + 'pug/email.pug', data);
    email({
      'from': 'Aida <aida@caliban.io>',
      'to': 'Martin <martind2000@gmail.com>',
      'subject': `ChangeDetection: ${data.name}`,
      'html': html,
      attachments: attachments
    });
  }

  async generateDiffScreenshot(previous, today) {

    let {dir, root, ext, name} = path.parse(today);

    const img1 = PNG.sync.read(fs.readFileSync(previous));
    const img2 = PNG.sync.read(fs.readFileSync(today));
    const {width, height} = img1;
    const diff = new PNG({width, height});

    pixelmatch(img1.data, img2.data, diff.data, width, height, {threshold: 0.1});


    name = name.concat('_diff');


    const endFilename = path.format({dir, root,  ext, name});



    logger.debug('diffFilename', endFilename);

    fs.writeFileSync(endFilename, PNG.sync.write(diff));

    return endFilename;


  }


  async processItem(item) {
    logger.debug(`Processing ${item.name}...`);

    const now = new Date();
    const filename = _.kebabCase(item.name);
    const oldFile = `${this.path}/${filename}.html`;
    const stats = this.stats.get(filename) || { 'lastSaved': now, 'lastChanged':null };

    await this._goto(item.url);

    await this._randomWait(this.page, 3, 5);

    const innerText = await this.page.evaluate(() => {
      return {
        'body': document.body.innerText
      };
    });

    const timestamp = dateFormat(now, 'yyyymmddHHMM');
    const screenshotPath = `${this.path}/screenshots/${filename}-${timestamp}`;

    if (!fs.existsSync(oldFile)) {
      fs.writeFileSync(oldFile, innerText.body, 'utf-8');
      stats.screenshot = screenshotPath;
      await this._makeScreenshotV2(this.page, screenshotPath, null);

      this.stats.set(filename, stats);
    }
    else {
      const previousFile = fs.readFileSync(oldFile, 'utf-8');

      const diff = new Diff(); // options may be passed to constructor; see below
      const textDiff = diff.main(previousFile, innerText.body); // produces diff array
      const cleanedDiff = diff.cleanupSemantic(textDiff);
      const levenshtein = diff.levenshtein(textDiff);

      logger.debug('levenshtein:', levenshtein);

      logger.debug('cleanedDiff:',cleanedDiff );

      if (levenshtein !== 0) {
        logger.info('Changed...');

        stats.previousScreenshot = stats.screenshot;
        stats.previousChange = stats.lastSaved;
        stats.lastSaved = now;
        stats.lastChanged = now;
        stats.screenshot = screenshotPath;
        stats.changed = diff.prettyHtml(textDiff);
        stats.levenshtein = levenshtein;
        stats.since = time.since(new Date(stats.previousChange)).days();

        await this._makeScreenshotV2(this.page, screenshotPath, null);

        stats.diffPNG = await this.generateDiffScreenshot(stats.previousScreenshot.concat('.png'), screenshotPath.concat('.png'));

        await this._randomWait(this.page, 3, 5);

        fs.writeFileSync(oldFile, innerText.body, 'utf-8');
        this.stats.set(filename, stats);

        const pugData = {...stats, ...item};

       // console.log(pugData);
        await this.sendSMTP(pugData, './');
      } else {
        logger.debug('No change...');
      }
    }
  }

  async processItems() {
    for (const item of this.settings)
      await this.processItem(item);
  }

  async processOld() {
    const options = {
      'ignoreAttributes': ['value', 'id', 'd'],
      'compareAttributesAsJSON': [],
      'ignoreWhitespaces': true,
      'ignoreComments': true,
      'ignoreEndTags': false,
      'ignoreDuplicateAttributes': false
    };

    const oldFile = `${this.path}/previous.html`;


    const innerText = await this.page.evaluate(() => {
      return {
        'body': document.body.innerText
      };
    });



    if (!fs.existsSync(oldFile))
      fs.writeFileSync(oldFile, body.body, 'utf-8');
    else {
      const previousFile = fs.readFileSync(oldFile, 'utf-8');

      const diff = new Diff(); // options may be passed to constructor; see below
      const textDiff = diff.main(previousFile, innerText.body); // produces diff array
      const levenshtein = diff.levenshtein(textDiff);

      logger.debug('levenshtein:', levenshtein);

      if (levenshtein !== 0) {
        logger.debug(diff.prettyHtml(textDiff));

       fs.writeFileSync(oldFile, innerText.body, 'utf-8');
      }
    }
  }

  async start() {
    await super._start();
    try{
      this.startPage = 'https://www.harmankardon.co.uk/outlet/';

      // this.startPage = 'https://silvrtree.co.uk/slack';
      const mouseDownDuration = ChangeDetection.notARobot();

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

      await this._createDirectory(`${this.path}/screenshots`);

      await this._initBrowser(true);
      await this._createBrowserPage();

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

      await this.page.setViewport({ 'width': 1200, 'height': 800 });
      // await this._goto(this.startPage);

      await this._randomWait(this.page, 3, 5);
      //  await this.page.waitForSelector('#SI_ID_Head_FromPrice');
      logger.debug('Started..');
      //  await this.page.click('#ctl00_cphRegistersMasterPage_lblViewList > a', { 'delay':mouseDownDuration });*/
    }
    catch(e) {
      throw new Error(e);
    }
  }

  async loadSettings() {
    logger.debug('Load settings...');
    const statsFile = `${this.path}/stats.json`;

    this.settings = jsonfile.readFileSync('settings.json');

    let stats = [];

    if (fs.existsSync(statsFile))
      stats = jsonfile.readFileSync(statsFile) || [];

    this.stats = new Map(stats);
  }

  async saveSettings() {
    logger.debug('Save settings...');
    const statsFile = `${this.path}/stats.json`;

    const stats = [...this.stats];
    // logger.debug(stats);
    jsonfile.writeFileSync(statsFile, stats);
  }

  /**
     * Grab the Pdf's and screenshots
     * @returns {Promise<void>}
     */
  async __run() {
   //  try {
    logger.debug('run');
    await this.start();

    // await this.process();

    await this.loadSettings();

    logger.debug('Running...');

    await this.processItems();

    await this.saveSettings();

      await this._done();
    /*}
    catch(e) {
      throw new Error(e);
    }*/
  }
}

module.exports = ChangeDetection;