angular.module('app').directive('areaChart', ['$window', '$translate', function($window, $translate) {
  return {
    restrict: 'A',
    scope: {
      config: '=',
      series: '='
    },
    link: function(scope, element) {
      var series = scope.series,
          config = scope.config,
          labels = config.labels,
          margin = { top: 15, right: 15, bottom: 35, left: 60 },
          fmt = d3.format('.3r'),
          fmtLong = d3.format('.2f'),
          func = series.func,
          drag = d3.behavior.drag(),
          dragging = false,
          // Define Axes
          xAxis = d3.svg.axis().outerTickSize(0).orient('bottom').tickFormat(d3.format('.2r')),
          yAxis = d3.svg.axis().ticks(6).outerTickSize(0).orient('left').tickFormat(fmt),
          x = d3.scale.linear(),
          y = d3.scale.linear(),
          data = [];

      // Create chart
      var svg = d3.select(element[0]).append('svg');
      var vis = svg.append('g').attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');

      // Define Area
      var area = d3.svg.area();

      var gradient = vis.append('defs')
        .append('linearGradient')
        .attr('id', 'gradient')
        .attr('x1', '0%').attr('y1', '0%')
        .attr('x2', '100%').attr('y2', '100%')
        .attr('spreadMethod', 'pad');
      gradient.append('stop')
        .attr('offset', '0%')
        .attr('stop-color', '#ff8c0d')
        .attr('stop-opacity', 1);
      gradient.append('stop')
        .attr('offset', '100%')
        .attr('stop-color', '#ff3b00')
        .attr('stop-opacity', 1);

      // Create Y Axis SVG Elements
      var yTxt = vis.append('g').attr('class', 'y axis')
        .append('text')
          .attr('class', 'cap')
          .attr('transform', 'rotate(-90)')
          .attr('y', -50)
          .attr('dy', '.1em')
          .style('text-anchor', 'middle')
          .text($translate.instant(labels.yAxis.title) + ' (' + $translate.instant(labels.yAxis.unit) + ')');
      // Create X Axis SVG Elements
      var xLbl = vis.append('g').attr('class', 'x axis');
      var xTxt = xLbl.append('text')
          .attr('y', 30)
          .attr('dy', '.1em')
          .style('text-anchor', 'middle')
          .text($translate.instant(labels.xAxis.title) + ' (' + $translate.instant(labels.xAxis.unit) + ')');

      // Create and Add tooltip
      var tip = vis.append('g').style('display', 'none');
      tip.append('rect').attr('width', '4.5em').attr('height', '2em').attr('x', '0.5em').attr('y', '-1em').attr('class', 'tip');
      tip.append('circle')
        .attr('class', 'marker')
        .attr('r', 4);
      tip.append('text').attr('class', 'label x').attr('y', '-0.25em');
      tip.append('text').attr('class', 'label y').attr('y', '0.85em');

      vis.insert('path', ':first-child')   // Area/Path to appear behind everything else
        .data([data])
        .attr('class', 'area')
        .attr('fill', 'url(#gradient)')
        .attr('d', area)
        .on('mouseover', showTip)
        .on('mouseout', hideTip)
        .on('mousemove', moveTip)
        .call(drag);

      drag
        .on('dragstart', function() {
          dragging = true;
          moveTip.call(this);
          showTip();
        })
        .on('dragend', function() {
          dragging = false;
          hideTip();
        })
        .on('drag', moveTip);

      /**
       * Watch for changes in the series data (mass changes, etc)
       */
      scope.$watchCollection('series', render);
      angular.element($window).bind('orientationchange resize render', render);

      function render() {
        var width = element[0].parentElement.offsetWidth,
            height = width * 0.5,
            w = width - margin.left - margin.right,
            h = height - margin.top - margin.bottom;

        data.length = 0;  // Reset Data array

        if (series.xMax == series.xMin) {
          var yVal = func(series.xMin);
          data.push([ series.xMin, yVal ]);
          data.push([ series.xMin, yVal ]);
          area.x(function(d, i) { return i * w; }).y0(h).y1(function(d) { return y(d[1]); });
        } else {
          for (var val = series.xMin; val <= series.xMax; val += 1) {
            data.push([ val, func(val) ]);
          }
          area.x(function(d) { return x(d[0]); }).y0(h).y1(function(d) { return y(d[1]); });
        }

        // Update Chart Size
        svg.attr('width', width).attr('height', height);
        // Update domain and scale for axes
        x.range([0, w]).domain([series.xMin, series.xMax]).clamp(true);
        xAxis.scale(x);
        xLbl.attr('transform', 'translate(0,' + h + ')');
        xTxt.attr('x', w / 2);
        y.range([h, 0]).domain([series.yMin, series.yMax]);
        yAxis.scale(y);
        yTxt.attr('x', -h / 2);
        vis.selectAll('.y.axis').call(yAxis);
        vis.selectAll('.x.axis').call(xAxis);

        vis.selectAll('path.area')   // Area/Path to appear behind everything else
          .data([data])
          .attr('d', area);
      }

      function showTip() {
       tip.style('display', null);
      }

      function hideTip() {
        if (!dragging) {
          tip.style('display', 'none');
        }
      }

      function moveTip() {
        var xPos = d3.mouse(this)[0], x0 = x.invert(xPos), y0 = func(x0), flip = (x0 / x.domain()[1] > 0.65);
        tip.attr('transform', 'translate(' + x(x0) + ',' + y(y0) + ')');
        tip.selectAll('rect').attr('x', flip ? '-5.75em' : '0.5em').style('text-anchor', flip ? 'end' : 'start');
        tip.selectAll('text.label').attr('x', flip ? '-2em' : '1em').style('text-anchor', flip ? 'end' : 'start');
        tip.select('text.label.x').text(fmtLong(x0) + ' ' + $translate.instant(labels.xAxis.unit));
        tip.select('text.label.y').text(fmtLong(y0) + ' ' + $translate.instant(labels.yAxis.unit));
      }

      scope.$on('$destroy', function() {
        angular.element($window).unbind('orientationchange resize render', render);
      });

    }
  };
}]);