/* globals d3 */
(function() {
  // 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/

  d3.bullet = function() {
    var orient = "right", // TODO top & bottom
      reverse = false,
      duration = 0,
      ranges = bulletRanges,
      markers = bulletMarkers,
      measures = bulletMeasures,
      width = 80,
      height = 30,
      tickFormat = null;

    // For each small multiple…
    function bullet(g) {
      g.each(function(d, i) {
        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),
          g = d3.select(this);

        // Compute the new x-scale.
        var x1 = d3.scale
          .linear()
          .domain([0, Math.max(rangez[0], markerz[0], measurez[0])])
          .range(reverse ? [width, 0] : [0, width - 160]);

        // 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);

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

        range
          .enter()
          .append("rect")
          .attr("class", function(d, i) {
            return "range s" + i;
          })
          .attr("width", w0)
          .attr("height", height)
          .attr("x", reverse ? x0 : 0)
          .transition()
          .duration(duration)
          .attr("width", w1)
          .attr("x", reverse ? x1 : 0);

        range
          .transition()
          .duration(duration)
          .attr("x", reverse ? x1 : 0)
          .attr("width", w1)
          .attr("height", height);

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

        measure
          .enter()
          .append("rect")
          .attr("class", function(d, i) {
            return "measure s" + i;
          })
          .attr("width", w0)
          .attr("height", height / 3)
          .attr("x", reverse ? x0 : 0)
          .attr("y", height / 3)
          .transition()
          .duration(duration)
          .attr("width", w1)
          .attr("x", reverse ? x1 : 0);

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

        // Update the marker lines.
        var marker = g.selectAll("line.marker").data(markerz);

        marker
          .enter()
          .append("line")
          .attr("class", function(d, i) {
            return "marker s" + i;
          })
          .attr("x1", x0)
          .attr("x2", x0)
          .attr("y1", height / 6)
          .attr("y2", (height * 5) / 6)
          .transition()
          .duration(duration)
          .attr("x1", x1)
          .attr("x2", x1);

        marker
          .transition()
          .duration(duration)
          .attr("x1", x1)
          .attr("x2", x1)
          .attr("y1", height / 6)
          .attr("y2", (height * 5) / 6);

        // Compute the tick format.
        var format = tickFormat || x1.tickFormat(8);

        // Update the tick groups.
        var tick = g.selectAll("g.tick").data(x1.ticks(8), function(d) {
          return this.textContent || format(d);
        });

        // Initialize the ticks with the old scale, x0.
        var tickEnter = tick
          .enter()
          .append("g")
          .attr("class", "tick")
          .attr("transform", bulletTranslate(x0))
          .style("opacity", 1e-6);

        tickEnter
          .append("line")
          .attr("y1", height)
          .attr("y2", (height * 7) / 6);

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

        // Transition the entering ticks to the new scale, x1.
        tickEnter
          .transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1);

        // Transition the updating ticks to the new scale, x1.
        var tickUpdate = tick
          .transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1);

        tickUpdate
          .select("line")
          .attr("y1", height)
          .attr("y2", height + 7);

        tickUpdate.select("text").attr("y", height + 7);

        // Transition the exiting ticks to the new scale, x1.
        tick
          .exit()
          .transition()
          .duration(duration)
          .attr("transform", bulletTranslate(x1))
          .style("opacity", 1e-6)
          .remove();
      });
      d3.timer.flush();
    }

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

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

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

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

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

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

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

    bullet.duration = function(x) {
      if (!arguments.length) return duration;
      duration = x;
      return bullet;
    };

    return bullet;
  };

  function bulletRanges(d) {
    return d.ranges;
  }

  function bulletMarkers(d) {
    return d.markers;
  }

  function bulletMeasures(d) {
    return d.measures;
  }

  function bulletTranslate(x) {
    return function(d) {
      return "translate(" + x(d) + ",0)";
    };
  }

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