var parseTime = d3.timeParse('%a %b %d %H:%M:%S +0000 %Y');
var formatTime = d3.timeFormat('%Y-%m-%d');
var parseFormattedTime = d3.timeParse('%Y-%m-%d');

var lineChart = function(data){
  // set the dimensions and margins of the graph
  var margin = {top: 20, right: 20, bottom: 60, left: 50},
      width = 800 - margin.left - margin.right,
      height = 600 - margin.top - margin.bottom;
  
  // set the ranges
  var x = d3.scaleTime().range([0, width]);
  var y = d3.scaleLinear().range([height, 0]);

  //add a new svg to hold the chart
  var svg = d3.select("body").append("svg")
   .attr("width", width + margin.left + margin.right)
   .attr("height", height + margin.top + margin.bottom)
   .append("g")
   .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

  // Scale the range of the data
  x.domain(d3.extent(data, function(d) { return parseTime(d.created_at); }));
  y.domain(d3.extent(data, function(d) { return +d.favorite_count; }));
  
  // Add the X Axis
  svg.append("g")
  	.attr('class', 'x axis')
    .call(d3.axisBottom(x).tickSize(height).ticks(5));

  // Add the Y Axis
  svg.append("g")
	  .attr('class', 'y axis')
  	.attr('transform', 'translate(' + width + ', 0)')
    .call(d3.axisLeft(y).tickSize(width).ticks(7));
  
  // Add a container for the circles
  var circles = svg.append('g')
  	.attr('id', 'circles');
  
  // Add the line path
  circles.selectAll("circle")
    .data(data)
  	.enter().append('circle')
    .attr('class', function(d) { return 'circle ' + d.source; })
    .attr('r', 3)
    .attr('cx', function(d) { return x(parseTime(d.created_at)); })
    .attr('cy', function(d) { return y(+d.favorite_count); })
  
  // add annotations
  var annotation = svg.append('g')
  	.attr('transform', 
          'translate(' + x(parseFormattedTime("2017-01-20")) + ',0)')
  	
  annotation.append('line')
    .attr('class', 'annotation')
		.attr('y1', 0)
    .attr('y2', height)
  
  annotation.append('text')
  	.text('Inauguration day')
  	.attr('text-anchor', 'end')
  	.attr('dx', -5)
    .attr('dy', 10)
  
	
};