var secondComing = "Turning and turning in the widening gyre\nThe falcon cannot hear the falconer;\nThings fall apart; the centre cannot hold;\nMere anarchy is loosed upon the world,\nThe blood-dimmed tide is loosed, and everywhere\nThe ceremony of innocence is drowned;\nThe best lack all conviction, while the worst\nAre full of passionate intensity.\n\nSurely some revelation is at hand;\nSurely the Second Coming is at hand.\nThe Second Coming! Hardly are those words out\nWhen a vast image out of Spiritus Mundi\nTroubles my sight: somewhere in sands of the desert\nA shape with lion body and the head of a man,\nA gaze blank and pitiless as the sun,\nIs moving its slow thighs, while all about it\nReel shadows of the indignant desert birds.\nThe darkness drops again; but now I know\nThat twenty centuries of stony sleep\nWere vexed to nightmare by a rocking cradle,\nAnd what rough beast, its hour come round at last,\nSlouches towards Bethlehem to be born?";

// decay text

d3.select("pre.thirty-seconds")
  .datum(secondComing)
  .call(decayText().domain([new Date(), new Date(+new Date() + 30*1000)]));

d3.select("pre.ten-minutes")
  .datum(secondComing)
  .call(decayText().domain([new Date(), new Date(+new Date() + 10*60*1000)]));

d3.select("pre.one-week")
  .datum(secondComing)
  .call(decayText().domain([new Date("2015-11-03"), new Date("2015-11-10")]));

// decay images

d3.select("img.thirty-seconds")
  .call(decayImage().domain([new Date(), new Date(+new Date() + 10*1000)]));

// d3.select("img.ten-minutes")
//   .call(decayImage().domain([new Date(), new Date(+new Date() + 10*60*1000)]));

// d3.select("img.one-week")
//   .call(decayImage().domain([new Date("2015-11-03"), new Date("2015-11-10")]));

// functions and stuff yo

function decayText() {
  var domain = [new Date(), new Date(+new Date() + 60*1000)],
      mutations = 0,
      decayScale = d3.time.scale();

  function decayer(selection) {
    selection.each(function(text) {

      var sel = d3.select(this)
        .text(text);

      decayScale = decayScale
        .domain(domain)
        .range([0,text.length/2]);

      d3.timer(function(t) {

        var mutationsToPerform = Math.floor(decayScale(new Date())) - mutations;

        if(mutationsToPerform > 0) {
          for (i = 0; i < mutationsToPerform; i++) {
            text = mutateText(text);
          }
          mutations += mutationsToPerform;
          sel.text(text);
        }

      })
    
    });
  }

  function mutateText(text) {
    var position = Math.floor(Math.random() * text.length);
    var insertion = Math.random() > .9 ? " " : Math.random().toString(36).substring(2,3);
    return stringSplice(text, position, 1, insertion);
  }

  // http://stackoverflow.com/a/21350614/120290
  function stringSplice(str, index, count, add) {
    return str.slice(0, index) + (add || "") + str.slice(index + count);
  }

  decayer.domain = function(_) {
    if (!arguments.length) return domain;
    domain = _;
    return decayer;
  };

  return decayer;
}

function decayImage() {
  var domain = [new Date(), new Date(+new Date() + 60*1000)],
      decayScale = d3.time.scale();

  function decayer(selection) {
    selection.each(function() {

      var sel = d3.select(this);

      decayScale = decayScale
        .domain(domain)
        .range([0,this.offsetWidth/5]);

      d3.timer(function(t) {
        sel.style("filter", "blur(" + decayScale(new Date()) + "px)");
        sel.style("-webkit-filter", "blur(" + decayScale(new Date()) + "px)");
        return new Date() > decayScale.domain()[1];
      })
    
    });
  }

  decayer.domain = function(_) {
    if (!arguments.length) return domain;
    domain = _;
    return decayer;
  };

  return decayer;
}