require("../env");

require("../../d3");

var vows = require("vows"),

    assert = require("assert");

var suite = vows.describe("d3.timer");

suite.addBatch({

  "timer": {

    topic: function() {

      return d3.timer;

    },

    "with no delay": {

      topic: timer(),

      "first calls after 17 ms or less": function(info) {

        assert.inDelta(info.start - info.scheduled, 17, 20);

      },

      "calls until the function returns true": function(info) {

        assert.equal(info.count, 4);

      },

      "calls every 17 ms": function(info) {

        assert.inDelta(info.stop - info.start, 17 * 3, 20);

      }

    },

    "with a specified delay": {

      topic: timer(250),

      "first calls after the delay": function(info) {

        assert.inDelta(info.start - info.scheduled, 250, 20);

      },

      "calls until the function returns true": function(info) {

        assert.equal(info.count, 4);

      },

      "calls every 17 ms": function(info) {

        assert.inDelta(info.stop - info.start, 17 * 3, 20);

      }

    }

  }

});

function timer(delay) {

  var args = Array.prototype.slice.call(arguments);

  return function() {

    var cb = this.callback,

        info = {scheduled: Date.now(), count: 0};

    args.unshift(function() {

      var count = ++info.count;

      if (count === 1) {

        info.start = Date.now();

      } else if (count === 4) {

        info.stop = Date.now();

        cb(null, info);

        return true;

      }

    });

    d3.timer.apply(this, args);

  };

}

suite.export(module);