// 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.bulletChart = function() {

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

  var bullet = nv.models.bullet()
    ;

  var orient = 'left' // TODO top & bottom
    , reverse = false
    , margin = {top: 5, right: 40, bottom: 20, left: 120}
    , ranges = function(d) { return d.ranges }
    , markers = function(d) { return d.markers }
    , measures = function(d) { return d.measures }
    , width = null
    , height = 55
    , tickFormat = null
    , tooltips = true
    , tooltip = function(key, x, y, e, graph) {
        return '<h3>' + x + '</h3>' +
               '<p>' + y + '</p>'
      }
    , noData = 'No Data Available.'
    , dispatch = d3.dispatch('tooltipShow', 'tooltipHide')
    ;

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


  //============================================================
  // Private Variables
  //------------------------------------------------------------

  var showTooltip = function(e, offsetElement) {
    var left = e.pos[0] + ( offsetElement.offsetLeft || 0 ) + margin.left,
        top = e.pos[1] + ( offsetElement.offsetTop || 0) + margin.top,
        content = tooltip(e.key, e.label, e.value, e, chart);

    nv.tooltip.show([left, top], content, e.value < 0 ? 'e' : 'w', null, offsetElement);
  };

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


  function chart(selection) {
    selection.each(function(d, i) {
      var container = d3.select(this);

      var availableWidth = (width  || parseInt(container.style('width')) || 960)
                             - margin.left - margin.right,
          availableHeight = height - margin.top - margin.bottom,
          that = this;


      chart.update = function() { chart(selection) };
      chart.container = this;

      //------------------------------------------------------------
      // Display No Data message if there's nothing to show.

      if (!d || !ranges.call(this, d, i)) {
        var noDataText = container.selectAll('.nv-noData').data([noData]);

        noDataText.enter().append('text')
          .attr('class', 'nvd3 nv-noData')
          .attr('dy', '-.7em')
          .style('text-anchor', 'middle');

        noDataText
          .attr('x', margin.left + availableWidth / 2)
          .attr('y', 18 + margin.top + availableHeight / 2)
          .text(function(d) { return d });

        return chart;
      } else {
        container.selectAll('.nv-noData').remove();
      }

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



      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 containers and skeleton of chart

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

      gEnter.append('g').attr('class', 'nv-bulletWrap');
      gEnter.append('g').attr('class', 'nv-titles');

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

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


      // Compute the new x-scale.
      var x1 = d3.scale.linear()
          .domain([0, Math.max(rangez[0], markerz[0], measurez[0])])  // 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;

      /*
      // Derive width-scales from the x-scales.
      var w0 = bulletWidth(x0),
          w1 = bulletWidth(x1);

      function bulletWidth(x) {
        var x0 = x(0);
        return function(d) {
          return Math.abs(x(d) - x(0));
        };
      }

      function bulletTranslate(x) {
        return function(d) {
          return 'translate(' + x(d) + ',0)';
        };
      }
      */

      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)) };


      var title = gEnter.select('.nv-titles').append('g')
          .attr('text-anchor', 'end')
          .attr('transform', 'translate(-6,' + (height - margin.top - margin.bottom) / 2 + ')');
      title.append('text')
          .attr('class', 'nv-title')
          .text(function(d) { return d.title; });

      title.append('text')
          .attr('class', 'nv-subtitle')
          .attr('dy', '1em')
          .text(function(d) { return d.subtitle; });



      bullet
        .width(availableWidth)
        .height(availableHeight)

      var bulletWrap = g.select('.nv-bulletWrap');

      d3.transition(bulletWrap).call(bullet);



      // Compute the tick format.
      var format = tickFormat || x1.tickFormat( availableWidth / 100 );

      // Update the tick groups.
      var tick = g.selectAll('g.nv-tick')
          .data(x1.ticks( availableWidth / 50 ), function(d) {
            return this.textContent || format(d);
          });

      // Initialize the ticks with the old scale, x0.
      var tickEnter = tick.enter().append('g')
          .attr('class', 'nv-tick')
          .attr('transform', function(d) { return 'translate(' + x0(d) + ',0)' })
          .style('opacity', 1e-6);

      tickEnter.append('line')
          .attr('y1', availableHeight)
          .attr('y2', availableHeight * 7 / 6);

      tickEnter.append('text')
          .attr('text-anchor', 'middle')
          .attr('dy', '1em')
          .attr('y', availableHeight * 7 / 6)
          .text(format);


      // Transition the updating ticks to the new scale, x1.
      var tickUpdate = d3.transition(tick)
          .attr('transform', function(d) { return 'translate(' + x1(d) + ',0)' })
          .style('opacity', 1);

      tickUpdate.select('line')
          .attr('y1', availableHeight)
          .attr('y2', availableHeight * 7 / 6);

      tickUpdate.select('text')
          .attr('y', availableHeight * 7 / 6);

      // Transition the exiting ticks to the new scale, x1.
      d3.transition(tick.exit())
          .attr('transform', function(d) { return 'translate(' + x1(d) + ',0)' })
          .style('opacity', 1e-6)
          .remove();


      //============================================================
      // Event Handling/Dispatching (in chart's scope)
      //------------------------------------------------------------

      dispatch.on('tooltipShow', function(e) {
        e.key = data[0].title;
        if (tooltips) showTooltip(e, that.parentNode);
      });

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

    });

    d3.timer.flush();

    return chart;
  }


  //============================================================
  // Event Handling/Dispatching (out of chart's scope)
  //------------------------------------------------------------

  bullet.dispatch.on('elementMouseover.tooltip', function(e) {
    dispatch.tooltipShow(e);
  });

  bullet.dispatch.on('elementMouseout.tooltip', function(e) {
    dispatch.tooltipHide(e);
  });

  dispatch.on('tooltipHide', function() {
    if (tooltips) nv.tooltip.cleanup();
  });

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


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

  chart.dispatch = dispatch;
  chart.bullet = bullet;

  d3.rebind(chart, bullet, 'color');

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

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

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

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

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

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

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

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

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

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


  return chart;
};