(function () {

  var isoFormat = 'YYYY-MM-DDTHH:mm:ss';

  function DlLineChartDirective($timeout, DillerClient) {
    var id_seq = 0;

    return {
      restrict: 'E',
      scope: {
        device: '=',
        property: '=',
        value: '=',
        interval: '='
      },
      replace: true,
      templateUrl: 'app/templates/line-chart.html',
      link: function (scope, element, attrs) {
        var elementId = element.attr('id');
        if (!elementId) {
          elementId = 'dl-line-chart-' + id_seq++;
          element.attr('id', elementId);
        }

        var deviceId = scope.device;
        var propertyId = scope.property;
        var interval = scope.interval; // TODO: watch scope.interval
        var property = DillerClient.getDevice(deviceId).getProperty(propertyId);

        var chart, chartData;
        var options = {
          axisX: {
            showLabel: true,
            showGrid: true,
            labelInterval: 1,
            labelInterpolationFnc: function (value, index) {
              return index % options.labelInterval === 0 ? value.format('HH:mm') : null;
            }
          }
        };

        function refresh() {
          property.getInterval(interval).then(function (data) {
            var avgs = _.pluck(data.values, 'avg');
            var timestamps = _.map(data.values, function (row) {
              return moment(row.timestamp, isoFormat);
            });

            chartData = {
              labels: timestamps,
              series: [
                avgs
              ]
            };

            options.labelInterval = Math.round(data.values.length / 10);

            if (!chart) {
              chart = new Chartist.Line('#' + elementId + ' .chart', chartData, options);
            } else {
              chart.update(chartData);
            }
          });
        }

        scope.setInterval = function (amount, type) {
          if (type == 'hours') {
            interval = Diller.Interval.hours(amount);
          } else if (type == 'days') {
            interval = Diller.Interval.days(amount);
          } else if (type == 'months') {
            interval = Diller.Interval.months(amount);
          }

          interval && refresh();
        };

        interval && refresh();
      }
    };
  }

  angular
    .module('diller.line-chart', ['diller.client'])
    .directive('dlLineChart', DlLineChartDirective);
})();