
// Chart design based on the recommendations of Stephen Few. Implementation
// based on the work of Clint Ivy, Jamie Love, and Jason Davies.
// http://projects.instantcognition.com/protovis/bulletchart/

nv.models.bullet = function() {

  //============================================================
  // Public Variables with Default Settings
  //------------------------------------------------------------

  var margin = {top: 0, right: 0, bottom: 0, left: 0}
    , orient = 'left' // TODO top & bottom
    , reverse = false
    , ranges = function(d) { return d.ranges }
    , markers = function(d) { return d.markers }
    , measures = function(d) { return d.measures }
    , forceX = [0] // List of numbers to Force into the X scale (ie. 0, or a max / min, etc.)
    , width = 380
    , height = 30
    , tickFormat = null
    , dispatch = d3.dispatch('elementMouseover', 'elementMouseout')
    ;

  //============================================================


  function chart(selection) {
    selection.each(function(d, i) {
      var availableWidth = width - margin.left - margin.right,
          availableHeight = height - margin.top - margin.bottom,
          container = d3.select(this),
          mainGroup = nv.log(this.parentNode.parentNode).getAttribute('transform'),
          heightFromTop = nv.log(parseInt(mainGroup.replace(/.*,(\d+)\)/,"$1"))); //TODO: There should be a smarter way to get this value

      var rangez = ranges.call(this, d, i).slice().sort(d3.descending),
          markerz = markers.call(this, d, i).slice().sort(d3.descending),
          measurez = measures.call(this, d, i).slice().sort(d3.descending);


      //------------------------------------------------------------
      // Setup Scales

      // Compute the new x-scale.
      var MaxX = Math.max(rangez[0] ? rangez[0]:0 , markerz[0] ? markerz[0] : 0 , measurez[0] ? measurez[0] : 0)
      var x1 = d3.scale.linear()
          .domain([0, MaxX]).nice()  // TODO: need to allow forceX and forceY, and xDomain, yDomain
          .range(reverse ? [availableWidth, 0] : [0, availableWidth]);

      // Retrieve the old x-scale, if this is an update.
      var x0 = this.__chart__ || d3.scale.linear()
          .domain([0, Infinity])
          .range(x1.range());

      // Stash the new scale.
      this.__chart__ = x1;

      //------------------------------------------------------------


      //------------------------------------------------------------
      // Setup containers and skeleton of chart

      var wrap = container.selectAll('g.nv-wrap.nv-bullet').data([d]);
      var wrapEnter = wrap.enter().append('g').attr('class', 'nvd3 nv-wrap nv-bullet');
      var gEnter = wrapEnter.append('g');
      var g = wrap.select('g');

      wrap.attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');

      //------------------------------------------------------------


      var w0 = function(d) { return Math.abs(x0(d) - x0(0)) }, // TODO: could optimize by precalculating x0(0) and x1(0)
          w1 = function(d) { return Math.abs(x1(d) - x1(0)) };


      // Update the range rects.
      var range = g.selectAll('rect.nv-range')
          .data(rangez);

      range.enter().append('rect')
          .attr('class', function(d, i) { return 'nv-range nv-s' + i; })
          .attr('width', w0)
          .attr('height', availableHeight)
          .attr('x', reverse ? x0 : 0)
          .on('mouseover', function(d,i) { 
              dispatch.elementMouseover({
                value: d,
                label: (i <= 0) ? 'Maximum' : (i > 1) ? 'Minimum' : 'Mean', //TODO: make these labels a variable
                pos: [x1(d), heightFromTop]
              })
          })
          .on('mouseout', function(d,i) { 
              dispatch.elementMouseout({
                value: d,
                label: (i <= 0) ? 'Minimum' : (i >=1) ? 'Maximum' : 'Mean' //TODO: make these labels a variable
              })
          })

      d3.transition(range)
          .attr('x', reverse ? x1 : 0)
          .attr('width', w1)
          .attr('height', availableHeight);


      // Update the measure rects.
      var measure = g.selectAll('rect.nv-measure')
          .data(measurez);

      measure.enter().append('rect')
          .attr('class', function(d, i) { return 'nv-measure nv-s' + i; })
          .attr('width', w0)
          .attr('height', availableHeight / 3)
          .attr('x', reverse ? x0 : 0)
          .attr('y', availableHeight / 3)
          .on('mouseover', function(d) { 
              dispatch.elementMouseover({
                value: d,
                label: 'Current', //TODO: make these labels a variable
                pos: [x1(d), heightFromTop]
              })
          })
          .on('mouseout', function(d) { 
              dispatch.elementMouseout({
                value: d,
                label: 'Current' //TODO: make these labels a variable
              })
          })

      d3.transition(measure)
          .attr('width', w1)
          .attr('height', availableHeight / 3)
          .attr('x', reverse ? x1 : 0)
          .attr('y', availableHeight / 3);


      // Update the marker lines.
      var marker = g.selectAll('path.nv-markerTriangle')
          .data(markerz);

      var h3 =  availableHeight / 6;
      marker.enter().append('path')
          .attr('class', 'nv-markerTriangle')
          .attr('transform', function(d) { return 'translate(' + x0(d) + ',' + (availableHeight / 2) + ')' })
          .attr('d', 'M0,' + h3 + 'L' + h3 + ',' + (-h3) + ' ' + (-h3) + ',' + (-h3) + 'Z')
          .on('mouseover', function(d,i) {
              dispatch.elementMouseover({
                value: d,
                label: 'Previous',
                pos: [x1(d), heightFromTop]
              })
          })
          .on('mouseout', function(d,i) {
              dispatch.elementMouseout({
                value: d,
                label: 'Previous'
              })
          });

      d3.transition(marker)
          .attr('transform', function(d) { return 'translate(' + x1(d) + ',' + (availableHeight / 2) + ')' });

      marker.exit().remove();

    });

    d3.timer.flush();

    return chart;
  }


  //============================================================
  // Expose Public Variables
  //------------------------------------------------------------

  chart.dispatch = dispatch;

  // left, right, top, bottom
  chart.orient = function(_) {
    if (!arguments.length) return orient;
    orient = _;
    reverse = orient == 'right' || orient == 'bottom';
    return chart;
  };

  // ranges (bad, satisfactory, good)
  chart.ranges = function(_) {
    if (!arguments.length) return ranges;
    ranges = _;
    return chart;
  };

  // markers (previous, goal)
  chart.markers = function(_) {
    if (!arguments.length) return markers;
    markers = _;
    return chart;
  };

  // measures (actual, forecast)
  chart.measures = function(_) {
    if (!arguments.length) return measures;
    measures = _;
    return chart;
  };

  chart.forceX = function(_) {
    if (!arguments.length) return forceX;
    forceX = _;
    return chart;
  };

  chart.width = function(_) {
    if (!arguments.length) return width;
    width = _;
    return chart;
  };

  chart.height = function(_) {
    if (!arguments.length) return height;
    height = _;
    return chart;
  };

  chart.margin = function(_) {
    if (!arguments.length) return margin;
    margin.top    = typeof _.top    != 'undefined' ? _.top    : margin.top;
    margin.right  = typeof _.right  != 'undefined' ? _.right  : margin.right;
    margin.bottom = typeof _.bottom != 'undefined' ? _.bottom : margin.bottom;
    margin.left   = typeof _.left   != 'undefined' ? _.left   : margin.left;
    return chart;
  };

  chart.tickFormat = function(_) {
    if (!arguments.length) return tickFormat;
    tickFormat = _;
    return chart;
  };

  //============================================================


  return chart;
};