var margin = {top: 0, right: 0, bottom: 0, left: 130},
    width = 1500 - margin.right - margin.left,
    height = 470 - margin.top - margin.bottom;

var i = 0,
    duration = 750,
    root;

var tree = d3.layout.tree()
    .size([height, width]);

var diagonal = d3.svg.diagonal()
    .projection(function(d) { return [d.y, d.x]; });

var svg = d3.select("#treeplot").append("svg")
    .attr("width", width + margin.right + margin.left)
    .attr("height", height + margin.top + margin.bottom)
    .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.json("/pattern_discovery/data?id={{selections.current_dataset}}", function(error, flare) {
    if (error) throw error;
    
    $("#wait").empty();
    
    root = flare;
    root.x0 = height / 2;
    root.y0 = 0;
    
    function collapse(d) {
        if (d.children) {
            d._children = d.children;
            d._children.forEach(collapse);
            d.children = null;
        }
    }
    
    root.children.forEach(collapse);
    update(root);
});

d3.select(self.frameElement).style("height", "800px");

function update(source) {
    
    // Compute the new tree layout.
    var nodes = tree.nodes(root).reverse(),
        links = tree.links(nodes);
    
    // Normalize for fixed-depth.
    nodes.forEach(function(d) { d.y = d.depth * 300; });
    
    // Update the nodes…
    var node = svg.selectAll("g.node")
        .data(nodes, function(d) { return d.id || (d.id = ++i); });
    
    // Enter any new nodes at the parent's previous position.
    var nodeEnter = node.enter().append("g")
        .attr("class", "node")
        .attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
        .on("click", click);
    
    nodeEnter.append("circle")
        .attr("r", 1e-6)
        .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
    
    nodeEnter.append("text")
        .attr("x", function(d) { return d.children || d._children ? -10 : 10; })
        .attr("dy", ".35em")
        .attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
        .text(function(d) { return d.name; })
        .style("fill-opacity", 1e-6);
    
    // Transition nodes to their new position.
    var nodeUpdate = node.transition()
        .duration(duration)
        .attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
    
    nodeUpdate.select("circle")
        .attr("r", 4.5)
        .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
    
    nodeUpdate.select("text")
        .style("fill-opacity", 1);
    
    // Transition exiting nodes to the parent's new position.
    var nodeExit = node.exit().transition()
        .duration(duration)
        .attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
        .remove();
    
    nodeExit.select("circle")
        .attr("r", 1e-6);
    
    nodeExit.select("text")
        .style("fill-opacity", 1e-6);
    
    // Update the links…
    var link = svg.selectAll("path.link")
        .data(links, function(d) { return d.target.id; });
    
    // Enter any new links at the parent's previous position.
    link.enter().insert("path", "g")
        .attr("class", "link")
        .attr("d", function(d) {
            var o = {x: source.x0, y: source.y0};
            return diagonal({source: o, target: o});
        });
    
    // Transition links to their new position.
    link.transition()
        .duration(duration)
        .attr("d", diagonal);
    
    // Transition exiting nodes to the parent's new position.
    link.exit().transition()
        .duration(duration)
        .attr("d", function(d) {
            var o = {x: source.x, y: source.y};
            return diagonal({source: o, target: o});
        })
        .remove();
    
    // Stash the old positions for transition.
    nodes.forEach(function(d) {
        d.x0 = d.x;
        d.y0 = d.y;
    });
}

// Toggle children on click.
function click(d) {
    if (d.children) {
        d._children = d.children;
        d.children = null;
    } else {
        d.children = d._children;
        d._children = null;
    }
    update(d);
}
