app.factory('fileReader', function ($http, $q) {
    var onLoad = function (reader, deferred, scope) {
        return function () {
            scope.$apply(function () {
                deferred.resolve(reader.result);
            });
        };
    };

    var onError = function (reader, deferred, scope) {
        return function () {
            scope.$apply(function () {
                deferred.reject(reader.result);
            });
        };
    };

    var onProgress = function (reader, scope) {
        return function (event) {
            scope.$broadcast("fileProgress",
            {
                total: event.total,
                loaded: event.loaded
            });
        };
    };

    var getReader = function (deferred, scope) {
        var reader = new FileReader();
        reader.onload = onLoad(reader, deferred, scope);
        reader.onerror = onError(reader, deferred, scope);
        reader.onprogress = onProgress(reader, scope);
        return reader;
    };

    var readAsDataURL = function (file, scope) {
        var deferred = $q.defer();

        var reader = getReader(deferred, scope);
        reader.readAsDataURL(file);

        return deferred.promise;
    };

    return {
        readAsDataUrl: readAsDataURL
    };
});