index.js

_prepareDocumentFiles (release, content) {
    const pagesCount = content.length;
    
    const pages = content.map(page => Object.assign({}, page)); // clone
    const resolutions = portals.getDocumentResolutions(release.portal_id);
    
    let watermark = null; // path to temp file with portal watermark
    let fullDocument = null; // path to temp file with combined pdf
    
    console.log(release, pages);
    
    return portals.getDocumentWatermark(release.portal_id)
      .then(_watermark => { watermark = _watermark; })
      // Make full document
      .then(pages => pdf.combineDocument(pages.map(p => p.filename)))
      .then(path => { fullDocument = path; })
      // Convert pages to image with max resolution
      // and prepare censored version with applied watermark
      .then(() => Promise
        .map(pages, page => pdf
          .documentToImages(page.filename, 300) // max resolution 2480x3508 for A4 page size
          .then(filename => {
            page.uncensored = {};
            page.censored = {};
            page.uncensoredPath = filename;
            page.censoredPath = watermark ? images.combine(filename, watermark) : filename;
            return Promise.props(page);
          }),
          { concurrency: 1 }
        )
      )
      // Prepare resolutions for each page
      .then(pages => Promise
        .map(pages, page => {
            // Resize uncensored versions
            page.uncensored = Promise
              .map(resolutions, res => {
                const [ w ] = res.split('x');
                return images.resize(page.uncensoredPath, res).then(file => ({ [w]: file }))
              }, { concurrency: 1 })
              .then(result => Object.assign({}, ...result));
            // Resize censored versions
            page.censored = Promise
              .map(resolutions, res => {
                const [ w ] = res.split('x');
                return images.resize(page.censoredPath, res).then(file => ({ [w]: file }))
              }, { concurrency: 1 })
              .then(result => Object.assign({}, ...result))
            return Promise.props(page);
          },
          { concurrency: 1 }
        )
      )
      // All files prepared, put them to the store
      .then(pages => {
        
      })
      
  }