function nextTick(cb) {
  setTimeout(cb, 0);
}

function parse_query() {
  var query = window.location.search.substring(1);
  var parsed = {};
  query.split('&').forEach(function(pair) {
    pair = pair.split('=');
    var key = decodeURIComponent(pair[0]);
    var value = decodeURIComponent(pair[1]);
    parsed[key] = value;
  });
  return parsed;
}

require(["Filer", "util"], function(Filer, util) {

  function time(test, cb) {
    var start = performance.now();
    function done() {
      var end = performance.now();
      cb(end - start);
    }
    test(done);
  }

  var random_data = new Uint8Array(1024); // 1kB buffer
  var read_buffer = new Uint8Array(1024);

  function run(iter) {
    iter = (undefined == iter) ? 0 : iter;

    function before() {
      util.setup(function() {
        nextTick(during);
      });
    }

    function during() {
      var fs = util.fs();

      window.crypto.getRandomValues(random_data);
      time(function(done) {
        fs.mkdir('/tmp', function(err) {
          fs.stat('/tmp', function(err, stats) {
            fs.open('/tmp/test', 'w', function(err, fd) {
              fs.write(fd, random_data, null, null, null, function(err, nbytes) {
                fs.close(fd, function(err) {
                  fs.stat('/tmp/test', function(err, stats) {
                    fs.open('/tmp/test', 'r', function(err, fd) {
                      fs.read(fd, read_buffer, null, null, null, function(err, nbytes) {
                        fs.close(fd, function(err) {
                          fs.unlink('/tmp/test', function(err) {
                            done();
                          });});});});});});});});});});
                        }, after);
                      }

                      function after(dt) {
                        util.cleanup(complete.bind(null, iter, dt));
                      }

                      before();
                    }

                    var results = [];
                    function complete(iter, result) {
                      results.push(result);

                      if(++iter < iterations) {
                        nextTick(run.bind(null, iter));
                      } else {
                        do_stats();
                      }

                      progress.value = iter;
                    }

                    function do_stats() {
                      var output = document.getElementById("output");
                      var stats = {
                        mean: ss.mean(results) + " ms",
                        min: ss.min(results),
                        max: ss.max(results),
                        med_abs_dev: ss.median_absolute_deviation(results),
                      };

                      var t = document.createElement("table");
                      var tbody = document.createElement("tbody");
                      var keys = Object.keys(stats);
                      keys.forEach(function(key) {
                        var row = document.createElement("tr");

                        var key_cell = document.createElement("td");
                        var key_cell_text = document.createTextNode(key);
                        key_cell.appendChild(key_cell_text);
                        row.appendChild(key_cell);

                        var val_cell = document.createElement("td");
                        var val_cell_text = document.createTextNode(stats[key]);
                        val_cell.appendChild(val_cell_text);
                        row.appendChild(val_cell);

                        tbody.appendChild(row);
                      });

                      t.appendChild(tbody);
                      output.appendChild(t);
                    }

                    var query = parse_query();
                    var iterations = query.iterations || 10;
                    var progress = document.getElementById("progress");
                    progress.max = iterations;

                    run();

});