logs_highcharts.js

var fs = require("fs");
var _ = require("underscore");
var utils = require("./public/js/shared_utils.js");

var UPDATE_FROM_LOGS_FREQUENCY = 1000 * 60 * 60 * 24;
var USAGE_HISTOGRAM_DAYS = 10;

// TODO: repetition of code here with the types
var FACT_TYPES = ["trivia", "math", "year", "date"];
var typeTimeHistogram = {};
var typeNumberHistogram = {};

function updateStatsFromLogs() {
  // Clear the histogram first
  _.each(FACT_TYPES, function (key) {
    typeTimeHistogram[key] = {};
    typeNumberHistogram[key] = {};
  });

  fs.readdir("./logs", function (err, files) {
    _.each(files, function (file) {
      fs.readFile("./logs/" + file, "utf-8", function (err, contents) {
        _.each(contents.split("\n"), function (logJson) {
          var logObj = null;

          try {
            logObj = JSON.parse(logJson);
          } catch (e) {}

          if (logObj) {
            try {
              reduceStats(logObj);
            } catch (e) {
              console.log("Failed reducing log file", file);
              console.log(e.message, e.stack);
            }
          }
        });
      });
    });
  });
}

function reduceStats(obj) {
  var timestamp = obj.time;
  var query = obj.query;
  var number = query.num || "random";
  if (query.month && query.day) {
    number = utils.monthDayToDayOfYear(query.month, query.day);
  }
  var type = query.type || "trivia";

  // There may be invalid types due to invalid user input
  if (!_.contains(FACT_TYPES, type)) return;

  // by time
  if (
    timestamp >=
    new Date().getTime() - 1000 * 60 * 60 * 24 * USAGE_HISTOGRAM_DAYS
  ) {
    var date = new Date(timestamp);
    var flooredDate = new Date(
      date.getFullYear(),
      date.getMonth(),
      date.getDate()
    );
    var flooredTime = flooredDate.getTime();
    var hist = typeTimeHistogram[type];
    if (!hist[flooredTime]) {
      hist[flooredTime] = 0;
    }
    hist[flooredTime] += 1;
  }

  // By number
  hist = typeNumberHistogram[type];
  if (!hist[number]) {
    hist[number] = 0;
  }
  hist[number] += 1;
}

updateStatsFromLogs();
setInterval(updateStatsFromLogs, UPDATE_FROM_LOGS_FREQUENCY);

function toHighchartsData(histogram, intKey) {
  var ret = {};
  _.each(histogram, function (hist, type) {
    ret[type] = _.map(hist, function (value, key) {
      if (intKey) key = +key;
      return [key, value];
    });
  });
  return ret;
}

exports.getTypeTimeHist = _.bind(
  toHighchartsData,
  null,
  typeTimeHistogram,
  true
);
exports.getTypeNumberHist = _.bind(toHighchartsData, null, typeNumberHistogram);