(function(d3) {
  d3.svg.polybrush = function() {
    var dispatch = d3.dispatch("brushstart", "brush", "brushend"),
        x = null,
        y = null,
        extent = [],
        firstClick = true,
        firstTime = true,
        wasDragged = false,
        origin = null,
        line = d3.svg.line()
          .x(function(d) {
            return d[0];
          })
          .y(function(d) {
            return d[1];
          });
    var brush = function(g) {
      g.each(function() {
        var bg, e, fg;
        g = d3.select(this);
        bg = g.selectAll(".background").data([0]);
        fg = g.selectAll(".extent").data([extent]);
        g.style("pointer-events", "all").on("click.brush", addAnchor);
        bg.enter().append("rect").attr("class", "background").style("visibility", "hidden").style("cursor", "crosshair");
        fg.enter().append("path").attr("class", "extent").style("cursor", "move");
        if (x) {
          e = scaleExtent(x.range());
          bg.attr("x", e[0]).attr("width", e[1] - e[0]);
        }
        if (y) {
          e = scaleExtent(y.range());
          bg.attr("y", e[0]).attr("height", e[1] - e[0]);
        }
      });
    };
    var drawPath = function() {
      return d3.selectAll("g path").attr("d", function(d) {
        return line(d) + "Z";
      });
    };
    var scaleExtent = function(domain) {
      var start, stop;
      start = domain[0];
      stop = domain[domain.length - 1];
      if (start < stop) {
        return [start, stop];
      } else {
        return [stop, start];
      }
    };
    var withinBounds = function(point) {
      var rangeX, rangeY, _x, _y;
      rangeX = scaleExtent(x.range());
      rangeY = scaleExtent(y.range());
      _x = Math.max(rangeX[0], Math.min(rangeX[1], point[0]));
      _y = Math.max(rangeY[0], Math.min(rangeY[1], point[1]));
      return point[0] === _x && point[1] === _y;
    };
    var moveAnchor = function(target) {
      var moved, point;
      point = d3.mouse(target);
      if (firstTime) {
        extent.push(point);
        firstTime = false;
      } else {
        if (withinBounds(point)) {
          extent.splice(extent.length - 1, 1, point);
        }
        drawPath();
        dispatch.brush();
      }
    };
    var closePath = function() {
      var w;
      w = d3.select(window);
      w.on("dblclick.brush", null).on("mousemove.brush", null);
      firstClick = true;
      if (extent.length === 2 && extent[0][0] === extent[1][0] && extent[0][1] === extent[1][1]) {
        extent.splice(0, extent.length);
      }
      d3.select(".extent").on("mousedown.brush", moveExtent);
      return dispatch.brushend();
    };
    var addAnchor = function() {
      var g, w,
        _this = this;
      g = d3.select(this);
      w = d3.select(window);
      firstTime = true;
      if (wasDragged) {
        wasDragged = false;
        return;
      }
      if (firstClick) {
        extent.splice(0, extent.length);
        firstClick = false;
        d3.select(".extent").on("mousedown.brush", null);
        w.on("mousemove.brush", function() {
          return moveAnchor(_this);
        }).on("dblclick.brush", closePath);
        dispatch.brushstart();
      }
      if (extent.length > 1) {
        extent.pop();
      }
      extent.push(d3.mouse(this));
      return drawPath();
    };
    var dragExtent = function(target) {
      var checkBounds, fail, p, point, scaleX, scaleY, updateExtentPoint, _i, _j, _len, _len1;
      point = d3.mouse(target);
      scaleX = point[0] - origin[0];
      scaleY = point[1] - origin[1];
      fail = false;
      origin = point;
      updateExtentPoint = function(p) {
        p[0] += scaleX;
        p[1] += scaleY;
      };
      for (_i = 0, _len = extent.length; _i < _len; _i++) {
        p = extent[_i];
        updateExtentPoint(p);
      }
      checkBounds = function(p) {
        if (!withinBounds(p)) {
          fail = true;
        }
        return fail;
      };
      for (_j = 0, _len1 = extent.length; _j < _len1; _j++) {
        p = extent[_j];
        checkBounds(p);
      }
      if (fail) {
        return;
      }
      drawPath();
      return dispatch.brush({
        mode: "move"
      });
    };
    var dragStop = function() {
      var w;
      w = d3.select(window);
      w.on("mousemove.brush", null).on("mouseup.brush", null);
      wasDragged = true;
      return dispatch.brushend();
    };
    var moveExtent = function() {
      var _this = this;
      d3.event.stopPropagation();
      d3.event.preventDefault();
      if (firstClick && !brush.empty()) {
        d3.select(window).on("mousemove.brush", function() {
          return dragExtent(_this);
        }).on("mouseup.brush", dragStop);
        origin = d3.mouse(this);
      }
    };
    brush.isWithinExtent = function(x, y) {
      var i, j, len, p1, p2, ret, _i, _len;
      len = extent.length;
      j = len - 1;
      ret = false;
      for (i = _i = 0, _len = extent.length; _i < _len; i = ++_i) {
        p1 = extent[i];
        p2 = extent[j];
        if ((p1[1] > y) !== (p2[1] > y) && x < (p2[0] - p1[0]) * (y - p1[1]) / (p2[1] - p1[1]) + p1[0]) {
          ret = !ret;
        }
        j = i;
      }
      return ret;
    };
    brush.x = function(z) {
      if (!arguments.length) {
        return x;
      }
      x = z;
      return brush;
    };
    brush.y = function(z) {
      if (!arguments.length) {
        return y;
      }
      y = z;
      return brush;
    };
    brush.extent = function(z) {
      if (!arguments.length) {
        return extent;
      }
      extent = z;
      return brush;
    };
    brush.clear = function() {
      extent.splice(0, extent.length);
      return brush;
    };
    brush.empty = function() {
      return extent.length === 0;
    };
    
    d3.rebind(brush, dispatch, "on");
    
    return brush;
  };
})(d3);