YellowLabTools/lib/tools/redownload/imageDimensions.js

var debug               = require('debug')('ylt:imageDimensions');
var Q                   = require('q');
var sizeOf              = require('image-size');

var ImageDimensions = function() {

    function getDimensions(entry) {
        var deferred = Q.defer();

        if (!entry.weightCheck || !entry.weightCheck.bodyBuffer) {
            // No valid file available
            deferred.resolve(entry);
            return deferred.promise;
        }

        var fileSize = entry.weightCheck.uncompressedSize;

        if (isJPEG(entry) || isPNG(entry)) {
            try {
                var dimensions = sizeOf(entry.weightCheck.bodyBuffer);
                debug('Image dimensions of %s: %sx%s', entry.url, dimensions.width, dimensions.height);

                entry.imageDimensions = {
                    width: dimensions.width,
                    height: dimensions.height
                };
            } catch(err) {
                debug('Error while checking image dimensions:');
                debug(err);
            }
        }
        
        deferred.resolve(entry);

        return deferred.promise;
    }

    function isJPEG(entry) {
        return entry.isImage && entry.contentType === 'image/jpeg';
    }

    function isPNG(entry) {
        return entry.isImage && entry.contentType === 'image/png';
    }

    return {
        getDimensions: getDimensions
    };
};

module.exports = new ImageDimensions();