// This is the main program that fetches Data Canvas - Sense Your City API.
// Curran Kelleher March 2015

require(["d3", "getData", "async"], function (d3, getData, async) {

  var now = Date.now(),
      pastDay =   now - 1000 * 60 * 60 * 24,
      pastWeek =  now - 1000 * 60 * 60 * 24 * 7,
      pastMonth = now - 1000 * 60 * 60 * 24 * 7 * 4;

  async.series([
    function(callback){
      d3.select("#day-loading").style("visibility", "visible");
      getData({
        resolution: "5m",
        from: new Date(pastDay).toISOString(),
        before: new Date(now).toISOString(),
      },function(err, data){
        d3.select("#day").text(toCSV(data));
        d3.select("#day-loading").style("visibility", "hidden");
        d3.select("#week-loading").style("visibility", "visible");
        callback();
      });
    },
    function(callback){
      getData({
        resolution: "1h",
        from: new Date(pastWeek).toISOString(),
        before: new Date(now).toISOString(),
      },function(err, data){
        d3.select("#week").text(toCSV(data));
        d3.select("#week-loading").style("visibility", "hidden");
        d3.select("#month-loading").style("visibility", "visible");
        callback();
      });
    },
    function(callback){
      getData({
        resolution: "1h",
        from: new Date(pastMonth).toISOString(),
        before: new Date(now).toISOString(),
      },function(err, data){
        d3.select("#month").text(toCSV(data));
        d3.select("#month-loading").style("visibility", "hidden");
        callback();
      });
    },
    function(callback){

      // 1 day in milliseconds.
      var msInterval = 1000 * 60 * 60 * 24,

          // Start fetching data from right now.
          msTime = Date.now(),

          // Get data from back in time 100 days.
          intervalCountMax = 100,

          // The running count of days we've fetched data for.
          intervalCount = 0,

          // The cumulative data as an array of objects.
          data = [];
    
      d3.select("#all-loading").style("visibility", "visible");

      async.whilst(
        function () { return intervalCount < intervalCountMax; },
        function (cb) {
          getData({
            resolution: "5m",
            from: new Date(msTime - msInterval * (intervalCount + 1)).toISOString(),
            before: new Date(msTime - msInterval * intervalCount).toISOString()
          },function(err, newData){

            data = _.sortBy(_.union(data, newData), "timestamp");

            d3.select("#all-counter").text([
              "Fetched " + data.length + " records",
              "over " + (intervalCount + 1) + " of " + intervalCountMax + " days"
            ].join("\n"));

            intervalCount++;

            cb();
          });
        }, function(err){

          d3.select("#all").text(toCSV(data));

          d3.select("#all-loading").style("visibility", "hidden");
          console.log("Done fetching data");
        }
      );

      callback();
    }
  ]);

  function toCSV(data){
    var columns = Object.keys(data[0]);
    return [columns.join(",")].concat(data.map(function(d){
      return columns.map(function(column){
        return d[column];
      }).join(",");
    })).join("\n");
  }

});