(function () {
  'use strict';

  angular.module('app.controller').controller('BaseUploadController', BaseUploadController);

  BaseUploadController.$inject = ['$scope', '$q', '$upload', 'cfg', 'apiUrl'];
  function BaseUploadController($scope, $q, $upload, cfg, apiUrl) {

    cfg.debug && console.log('BaseUploadController');

    $scope.upload = this;

    /**
     * @abstract
     * @return {String}
     */
    this.getControllerAction = function () {
      throw new Error('Method BaseUploadController.getControllerAction should be overwritten');
    };

    /**
     * @param {Number} index
     * @return {Object}
     */
    this.getRequest = function (index) {
      return {
//        headers: {'key': 'value'},
//        data: {
//          key: 'value'
//        }
      };
    };

    this.autoStart = false;

    /**
     * List of selected files
     * @type {Array.<File>}
     */
    this.listSelected = [];

    /**
     * Progress of each upload
     * @type {Array.<Number>} ex. -1..100
     */
    this.progress = [];

    /**
     * List of http promises for uploads with additional method .abort()
     * Filled after upload starts
     * @type {Array.<promise>}
     */
    this.list = [];

    /**
     * List of responses for each upload
     * Filled after upload finished
     * @type {Array}
     */
    this.listResult = [];

    /**
     * Indicates that all selected files proceeded
     * @readonly
     * @type {boolean}
     */
    this.complete = true;

    this.refreshComplete = function () {
      this.complete = (this.listSelected.filter(function (v) { return !!v; }).length === this.listResult.length);
    };

    /**
     * ex.: ng-file-select="upload.onFileSelect($files)"
     * @param {Array.<File>} $files
     */
    this.onFileSelect = function ($files) {
      var i;
      this.listSelected = [];
      this.progress = [];
      if (this.list && this.list.length > 0) {
        for (i = 0; i < this.list.length; i++) {
          if (this.list[i] != null) {
            this.list[i].abort();
          }
        }
      }
      this.list = [];
      this.listResult = [];
      this.listSelected = $files;

      this.refreshComplete();

      for (i = 0; i < $files.length; i++) {
        this.progress[i] = -1;
        if (this.autoStart) {
          this.start(i);
        }
      }
    };

    this.start = function (index) {
      return this.upload(index);
    };

    this.remove = function (index) {
      if (this.list[index]) {
        this.abort(index);
      }
      if (this.listSelected[index]) {
        this.listSelected[index] = null;
      }
      this.refreshComplete();
    };

    this.abort = function (index) {
      if (this.list[index]) {
        this.list[index].abort();
      }
      this.list[index] = null;
      this.progress[index] = -1;
      this.listResult[index] = false;
      this.refreshComplete();
    };

    this.upload = function (index) {
      var deferred = $q.defer();
      this.progress[index] = 0;
      this.list[index] = $upload.upload(angular.extend({
          url: apiUrl + '/' + this.getControllerAction(),
          method: 'post',
          file: this.listSelected[index]
        }, this.getRequest(index))
      ).then(this.onDone.bind(this, index, deferred), this.onFail.bind(this, index, deferred), this.onNotify.bind(this, index));

      this.refreshComplete();

      return deferred.promise;
    };

    this.onDone = function (index, deferred, response) {
      this.list[index] = null;
      this.listResult[index] = response.data;
      this.refreshComplete();
      deferred.resolve(response);
    };

    this.onFail = function (index, deferred, response) {
      this.list[index] = null;
      this.listResult[index] = false;
      this.refreshComplete();
      deferred.reject(response);
    };

    this.onNotify = function (index, e) {
      this.progress[index] = parseInt(100.0 * e.loaded / e.total);
    };

  }

})();