var svg = d3.select("svg")

/*
 sample row (u(integer) stands for unused field)
 num,date,time,bsl,id,u1,u2,u3,u4,....,u12
 "165", "02/02/2016", "08:26:20", "15.76"
 
 onetouch .csv writer generates a verbose format.
 
*/

// "02/02/2016/08:26:20"
var format = d3.time.format("%m/%d/%Y/%H:%M:%S");

d3.csv("sugars.csv", function(error, data) {
  if (error) throw error;
  data = csv_preprocessor(data);
  
  d3.json("compiled.json", function(error, food) {
    if (error) throw error;
    food = json_preprocessor(food);
    
    // both data and food are processed, ready to rock.
    draw_graph(data, food);
  });
  
});

function csv_preprocessor(data){
  
  // reduce down to : UNIXTIME / BSL
  data.forEach(function(d) {
    var unix_str = d.date + "/" + d.time;
    var date_stamp = format.parse(unix_str);
    d.unix = d3.time.hour.offset(date_stamp, 1);  // gmt to dutch
    d.bsl = +d.bsl;
  });
  
  return data;
}

function json_preprocessor(p){
  var new_object_array = [];
  for (var key in p) {
    if (p.hasOwnProperty(key)) {
      var gmt = format.parse(key);
      var unix = d3.time.hour.offset(gmt, 0);
      new_object_array.push({time: unix, statement: p[key]});
    }
  }
  return new_object_array;

}

function draw_graph(data, food){
  
  var margin = {top: 20, right: 80, bottom: 30, left: 50},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

  var x = d3.time.scale()
      .range([0, width]);
  
  var x2 = d3.time.scale()
      .range([0, width]);
    
  var y = d3.scale.linear()
      .range([height, 0]);

  var y2 = d3.scale.linear()
      .range([height, 0]);
  
  var xAxis = d3.svg.axis()
      .scale(x)
      .ticks(d3.time.days, 1)
      .orient("bottom");

  var yAxis = d3.svg.axis()
      .scale(y)
      .orient("left");

  var x2Axis = d3.svg.axis()
      .scale(x2)
      .orient("top");

  var y2Axis = d3.svg.axis()
      .scale(y2)
      .orient("right");
    
  
  function adjust_date(date, add){
     return d3.time.day.offset(date, add)
  }
  var first_day = adjust_date(data[data.length - 1].unix, -1)
  var last_day = adjust_date(data[0].unix, 1)
  
  x.domain([first_day, last_day]);
  x2.domain([first_day, last_day]);
  y.domain(d3.extent(data, function(d) { return d.bsl; }));
  y2.domain([0, 24]);
  
  svg
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom);
  
  var g1 = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

  var g2 = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
  
  g1.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0, " + height + ")")
      .call(xAxis);

  g1.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Glucose");  

  g2.append("g")
      .attr("class", "y2 axis")
      .attr("transform", "translate(" + width + ", 0)")
      .call(y2Axis)
  
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", width)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Food time");  
  
  
  
  var circle = g1.selectAll('circle').data(data);
  var circleEnter = circle.enter().append('circle');
  circleEnter 
     .attr("cx", function(d, i){return x(d.unix);})
     .attr("cy", function(d, i){return y(d.bsl);})
     .attr("r", function(d, i) {return 3})
     .style({fill: "#fe42ec"})
    
  var crect = g2.selectAll('rect').data(food);
  var crectEnter = crect.enter().append('rect');
  crectEnter
    .attr("width", 7)
    .attr("height", 13)
    .attr("x", function(d, i){return x2(d.time);})
    .attr("y", function(d, i){return y2(d.time.getHours());})
    .attr("r", 3)
    .style({fill: "#56feb3"})
  
}