var log = console.log;
var margin = {top: 30, right: 0, bottom: 0, left: 0};
var width = 800;
var height = 670 - margin.top - margin.bottom;
var transitioning;

// x axis scale
var x = d3.scale.linear()
.domain([0, width])
.range([0, width]);

// y axis scale
var y = d3.scale.linear()
.domain([0, height])
.range([0, height]);



// treemap layout
var treemap = d3.layout.treemap()
.children(function(d, depth) { return depth ? null : d._children; })
.sort(function(a, b) { return a.value - b.value; })
.ratio(height / width * 0.5 * (1 + Math.sqrt(5)))
.value(d=>d.sum)
.round(false);

// define svg
var svg = d3.select("#chart").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.bottom + margin.top)
.style("margin-left", -margin.left + "px")
.style("margin.right", -margin.right + "px")
.append("g")
.attr("transform", `translate(${margin.left},${margin.top})`)
.style("shape-rendering", "crispEdges");

// top gray rectangle
var grandparent = svg.append("g")
.attr("class", "grandparent");

// Add grandparent rect
grandparent.append("rect")
.attr("y", -margin.top)
.attr("width", width)
.attr("height", margin.top)
.style("fill", "#d9d9d9");

// Add grandparent text
grandparent.append("text")
.attr("class", "title")
.attr("x", 6)
.attr("y", 6 - margin.top)
.attr("dy", ".75em");        

// custom root initializer
function initialize(root) {
  root.x = root.y = 0;
  root.dx = width;
  root.dy = height;
  root.depth = 0;
};

// Aggregate the values for internal nodes. This is normally done by the
// treemap layout, but not here because of our custom implementation.
// We also take a snapshot of the original children (_children) to avoid
// the children being overwritten when when layout is computed.
// Alteration made for function to be iterative
function accumulateVal(d, attr) {
  return accumulate(d);

  function accumulate(d) {
    return (d._children = d.children)
    // recursion step, note that p and v are defined by reduce
    ? d[attr] = d.children.reduce(function(p, v) {return p + accumulate(v); }, 0)
    : d[attr];
  };
};

// Compute the treemap layout recursively such that each group of siblings
// uses the same size (1×1) rather than the dimensions of the parent cell.
// This optimizes the layout for the current zoom state. Note that a wrapper
// object is created for the parent node for each group of siblings so that
// the parent’s dimensions are not discarded as we recurse. Since each group
// of sibling was laid out in 1×1, we must rescale to fit using absolute
// coordinates. This lets us use a viewport to zoom.
function layout(d) {
  if (d._children) {
    // treemap nodes comes from the treemap set of functions as part of d3
    treemap.nodes({_children: d._children});
    d._children.forEach(function(c) {
      c.x = d.x + c.x * d.dx;
      c.y = d.y + c.y * d.dy;
      c.dx *= d.dx;
      c.dy *= d.dy;
      c.parent = d;
      // recursion
      layout(c);
    });
  }
};

d3.csv("Public_Grants_2010-2012(July-28-2018).csv", treeMapZoomable);

function treeMapZoomable(error, grants) {
  if (error) throw error;

  // Define color scale
  var allValues = grants.map(function(d) { return [d["GRANT_PROGRAM"], d["YEAR"]]; })
  .reduce(function(acc, curVal) { return acc.concat(curVal); }, []);
  var scaleOrdNames = [...new Set(allValues)];
  var colorScale = d3.scale.ordinal().domain(scaleOrdNames)
  .range(['#66c2a5','#fc8d62','#8da0cb','#e78ac3','#a6d854','#ffd92f','#e5c494']);

  // Define aggregrated grant programs
  var aggGrantPrograms = d3.nest().key(function(d) { return d.YEAR; })
  .key(function(d) { return d["GRANT_PROGRAM"]; })
  .entries(grants)
  .map(function(d) {
    var dValues = d.values.map(function(g){
      var gValues = g.values;
      var sum = gValues.map(function(p) { return p["GRANT_AWARD"]; })
      .reduce(function(acc, curVal) { return acc + (+curVal); }, 0);

      return {
        name: g.key,
        value: gValues.length,
        sum: sum
      };
    });

    return {
      name: d.key,
      children: dValues
    };
  });

  // Root for hierarchy
  var rootObject = {name: "Office", children: aggGrantPrograms};

  initialize(rootObject);
  ["value", "sum"].forEach(function(d) { accumulateVal(rootObject, d); });
  layout(rootObject);
  display(rootObject);

  function display(d) {
    // Grandparent when clicked transitions the children out to parent 
    grandparent
    .datum(d.parent)
    .on("click", transition)
    .select("text.title")
    .text(name(d));

    grandparent
    .datum(d.parent)
    .select("rect");

    var g1 = svg.insert("g", ".grandparent")
    .datum(d)
    .attr("class", "depth");

    var g = g1.selectAll("g")
    .data(d._children)
    .enter().append("g");

    // When parent is clicked transitions to children
    g.filter(function(d) { return d._children; })
    .classed("children", true)
    .on("click", transition);

    g.selectAll(".child")
    .data(function(d) { return d._children || [d]; })
    .enter().append("rect")
    .attr("class", "child")
    .call(rect);

    g.append("rect")
    .attr("class", "parent")
    .call(rect)
    .append("title")
    .text(function(d) { return `Audience Segment: ${d.name}`; });
    
    // functiom to wrap text
    
    function stringDivider(str, width, spaceReplacer) {
    if (str.length>width) {
        var p=width
        for (;p>0 && str[p]!=' ';p--) {
        }
        if (p>0) {
            var left = str.substring(0, p);
            var right = str.substring(p+1);
            return left + spaceReplacer + stringDivider(right, width, spaceReplacer);
        }
    }
    return str;
}
    

    // Appending year, grants, and sum texts for each g
    var textClassArr = [
      {class: "year", accsor: function(d) { return d.name; }}, 
      {class: "sum", accsor: function(d) { return stringDivider(`${d.sum.toLocaleString()}`, 12, "<br/>\n") ; }}
      ];

    textClassArr.forEach(function(p, i) {
      g.append("text")
      .attr("class", p.class)
      .attr("dy", ".5em")
      .text(p.accsor)
      .call(rectText(i));
    });

    function transition(d) {
      if (transitioning || !d) return;
      transitioning = true;

      var g2 = display(d);
      var t1 = g1.transition().duration(750);
      var t2 = g2.transition().duration(750);

      // Update the domain only after entering new elements.
      x.domain([d.x, d.x + d.dx]);
      y.domain([d.y, d.y + d.dy]);

      // Enable anti-aliasing during the transition.
      svg.style("shape-rendering", null);

      // Draw child nodes on top of parent nodes.
      svg.selectAll(".depth").sort(function(a, b) { return a.depth - b.depth; });

      // Fade-in entering text.
      g2.selectAll("text").style("fill-opacity", 0);

      // Transition to the new view.
      textClassArr.forEach(function(d, i) {
        var textClass = `text.${d.class}`;
        var textPlacmt = rectText(i);

        t1.selectAll(textClass).call(textPlacmt).style("fill-opacity", 0);
        t2.selectAll(textClass).call(textPlacmt).style("fill-opacity", 1);
      });

      t1.selectAll("rect").call(rect);
      t2.selectAll("rect").call(rect);

      // Remove the old node when the transition is finished.
      t1.remove().each("end", function() {
        svg.style("shape-rendering", "crispEdges");
        transitioning = false;
      });                 
    };

    return g;
  };

  function rectText(i) {
    return grantText;

    function grantText(text) {
      return text.attr("x", function(d) { return x(d.x) + 6; })
      .attr("y", function(d) { return y(d.y) + (25 + (i * 18)); })
      .attr("fill", "black");
    };
  };

  function rect(rect) {
    rect.attr("x", function(d) { return x(d.x); })
    .attr("y", function(d) { return y(d.y); })
    .attr("width", function(d) { return x(d.x + d.dx) - x(d.x); })
    .attr("height", function(d) { return y(d.y + d.dy) - y(d.y); })
    .attr("fill", function(d) { return colorScale(d.name);});
  };

  function name(d) {
    return d.parent
    ? `${name(d.parent)}.${d.name} - Total Segments: ${d.value} - 
      Sample Size: ${d.sum.toLocaleString()}`
    : d.name;
  };

};