// Word cloud layout by Jason Davies, http://www.jasondavies.com/word-cloud/
// Algorithm due to Jonathan Feinberg, http://static.mrfeinberg.com/bv_ch03.pdf
var ModestCanvas = typeof ModestCanvas != "undefined" ? ModestCanvas : {};
ModestCanvas.wordCloud = function(container, cloudData, args){
  var jsonData = cloudData;
  d3WordCloudInit();
  if(args == undefined){args = {}}
  var maxFontSize = args.maxFontSize || 50;
  var minFontSize = args.minFontSize || 14;
  var minCategoryFillColor = args.minCategoryFillColor || "#7c68a9";
  var maxCategoryFillColor = args.maxCategoryFillColor || "#80696a";

  var elementContainer = d3.select(container);
  var margin = {top: 20, right: 20, bottom: 40, left: 20},
    width = elementContainer.node().getBoundingClientRect().width - margin.left - margin.right,
    height = 400 - margin.top - margin.bottom;
  var categories = d3.nest().key(function(d) { return d.category; }).map(jsonData).keys();
  var maxFrequency = Math.max.apply(Math, d3.nest().key(function(d) { return d.frequency; }).map(jsonData).keys());
  var minFrequency = Math.min.apply(Math, d3.nest().key(function(d) { return d.frequency; }).map(jsonData).keys());
  var fontSize = d3.scalePow().exponent(2).domain([minFrequency, maxFrequency]).range([minFontSize,maxFontSize]);
  var color = d3.scaleOrdinal().domain(categories).range(d3.range(categories.length).map(d3.scaleLinear().domain([0, categories.length - 1]).range([minCategoryFillColor, maxCategoryFillColor]).interpolate(d3.interpolateLab)));
  var layout = d3.cloud()
      .timeInterval(10)
      .size([width, height])
      .words(jsonData)
      .rotate(function(d) { return Math.random() > 0.5 ? 0 : -90; })
      .fontSize(function(d,i) { return fontSize(d.frequency); })
      .text(function(d) { return d.word; })
      .spiral("archimedean")
      .on("end", draw)
      .start();

  var svg = elementContainer
    .classed('d3_word_cloud', true)
    .append("svg")
      .classed('d3_word_cloud_svg', true)
      .attr("preserveAspectRatio", "xMinYMin meet")
      .attr("viewBox", "0 0 " + (width + margin.left + margin.right) + " " + (height + margin.top + margin.bottom))
    .append("g")
      .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

  var wordcloud = svg.append("g")
      .attr('class','wordcloud')
      .attr("transform", "translate(" + width/2 + "," + height/2 + ")");

  if(categories.length && args.hideCategoryAxis != true){
    var x0 = d3.scaleBand()
      .range([0, width])
      .round(.1)
      .domain(categories);

    var xAxis = d3.axisBottom()
        .scale(x0);

    svg.append("g")
        .attr("class", "x axis")
        .classed('categories_axis', true)
        .attr("transform", "translate(0," + height + ")")
        .call(xAxis)
      .selectAll('text')
        .style('fill',function(d) { return color(d); });
  }

  function draw(words) {
    wordcloud.selectAll("text")
      .data(words)
    .enter().append("text")
      .attr('class','word')
      .style("font-size", function(d) { return d.size + "px"; })
      .style("fill", function(d) {
        return color(d.category);
      })
      .attr("text-anchor", "middle")
      .attr("transform", function(d) { return "translate(" + [d.x, d.y] + ")rotate(" + d.rotate + ")"; })
      .text(function(d) { return d.text; });
  };

  function d3WordCloudInit() {
    if (typeof define === "function" && define.amd) define(["d3"], cloud);
    else cloud(this.d3);
    var cloudRadians = Math.PI / 180,
      cw = 1 << 11 >> 5,
      ch = 1 << 11;

    function cloud(d3) {
      d3.cloud = function cloud() {
        var size = [256, 256],
          text = cloudText,
          font = cloudFont,
          fontSize = cloudFontSize,
          fontStyle = cloudFontNormal,
          fontWeight = cloudFontNormal,
          rotate = cloudRotate,
          padding = cloudPadding,
          spiral = archimedeanSpiral,
          words = [],
          timeInterval = Infinity,
          event = d3.dispatch("word", "end"),
          timer = null,
          random = Math.random,
          cloud = {},
          canvas = cloudCanvas;

        cloud.canvas = function(_) {
          return arguments.length ? (canvas = functor(_), cloud) : canvas;
        };

        cloud.start = function() {
          var contextAndRatio = getContext(canvas()),
            board = zeroArray((size[0] >> 5) * size[1]),
            bounds = null,
            n = words.length,
            i = -1,
            tags = [],
            data = words.map(function(d, i) {
              d.text = text.call(this, d, i);
              d.font = font.call(this, d, i);
              d.style = fontStyle.call(this, d, i);
              d.weight = fontWeight.call(this, d, i);
              d.rotate = rotate.call(this, d, i);
              d.size = ~~fontSize.call(this, d, i);
              d.padding = padding.call(this, d, i);
              return d;
            }).sort(function(a, b) { return b.size - a.size; });

          if (timer) clearInterval(timer);
          timer = setInterval(step, 0);
          step();

          return cloud;

          function step() {
            var start = Date.now();
            while (Date.now() - start < timeInterval && ++i < n && timer) {
              var d = data[i];
              d.x = (size[0] * (random() + .5)) >> 1;
              d.y = (size[1] * (random() + .5)) >> 1;
              cloudSprite(contextAndRatio, d, data, i);
              if (d.hasText && place(board, d, bounds)) {
                tags.push(d);
                event.call("word", cloud, d);
                if (bounds) cloudBounds(bounds, d);
                else bounds = [{x: d.x + d.x0, y: d.y + d.y0}, {x: d.x + d.x1, y: d.y + d.y1}];
                // Temporary hack
                d.x -= size[0] >> 1;
                d.y -= size[1] >> 1;
              }
            }
            if (i >= n) {
              cloud.stop();
              event.call("end", cloud, tags, bounds);
            }
          }
        }

        cloud.stop = function() {
          if (timer) {
            clearInterval(timer);
            timer = null;
          }
          return cloud;
        };

        function getContext(canvas) {
          canvas.width = canvas.height = 1;
          var ratio = Math.sqrt(canvas.getContext("2d").getImageData(0, 0, 1, 1).data.length >> 2);
          canvas.width = (cw << 5) / ratio;
          canvas.height = ch / ratio;

          var context = canvas.getContext("2d");
          context.fillStyle = context.strokeStyle = "red";
          context.textAlign = "center";

          return {context: context, ratio: ratio};
        }

        function place(board, tag, bounds) {
          var perimeter = [{x: 0, y: 0}, {x: size[0], y: size[1]}],
              startX = tag.x,
              startY = tag.y,
              maxDelta = Math.sqrt(size[0] * size[0] + size[1] * size[1]),
              s = spiral(size),
              dt = random() < .5 ? 1 : -1,
              t = -dt,
              dxdy,
              dx,
              dy;

          while (dxdy = s(t += dt)) {
            dx = ~~dxdy[0];
            dy = ~~dxdy[1];

            if (Math.min(Math.abs(dx), Math.abs(dy)) >= maxDelta) break;

            tag.x = startX + dx;
            tag.y = startY + dy;

            if (tag.x + tag.x0 < 0 || tag.y + tag.y0 < 0 ||
                tag.x + tag.x1 > size[0] || tag.y + tag.y1 > size[1]) continue;
            // TODO only check for collisions within current bounds.
            if (!bounds || !cloudCollide(tag, board, size[0])) {
              if (!bounds || collideRects(tag, bounds)) {
                var sprite = tag.sprite,
                    w = tag.width >> 5,
                    sw = size[0] >> 5,
                    lx = tag.x - (w << 4),
                    sx = lx & 0x7f,
                    msx = 32 - sx,
                    h = tag.y1 - tag.y0,
                    x = (tag.y + tag.y0) * sw + (lx >> 5),
                    last;
                for (var j = 0; j < h; j++) {
                  last = 0;
                  for (var i = 0; i <= w; i++) {
                    board[x + i] |= (last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0);
                  }
                  x += sw;
                }
                delete tag.sprite;
                return true;
              }
            }
          }
          return false;
        }

        cloud.timeInterval = function(_) {
          return arguments.length ? (timeInterval = _ == null ? Infinity : _, cloud) : timeInterval;
        };

        cloud.words = function(_) {
          return arguments.length ? (words = _, cloud) : words;
        };

        cloud.size = function(_) {
          return arguments.length ? (size = [+_[0], +_[1]], cloud) : size;
        };

        cloud.font = function(_) {
          return arguments.length ? (font = functor(_), cloud) : font;
        };

        cloud.fontStyle = function(_) {
          return arguments.length ? (fontStyle = functor(_), cloud) : fontStyle;
        };

        cloud.fontWeight = function(_) {
          return arguments.length ? (fontWeight = functor(_), cloud) : fontWeight;
        };

        cloud.rotate = function(_) {
          return arguments.length ? (rotate = functor(_), cloud) : rotate;
        };

        cloud.text = function(_) {
          return arguments.length ? (text = functor(_), cloud) : text;
        };

        cloud.spiral = function(_) {
          return arguments.length ? (spiral = spirals[_] || _, cloud) : spiral;
        };

        cloud.fontSize = function(_) {
          return arguments.length ? (fontSize = functor(_), cloud) : fontSize;
        };

        cloud.padding = function(_) {
          return arguments.length ? (padding = functor(_), cloud) : padding;
        };

        cloud.random = function(_) {
          return arguments.length ? (random = _, cloud) : random;
        };

        cloud.on = function() {
          var value = event.on.apply(event, arguments);
          return value === event ? cloud : value;
        };

        return cloud;
      };

      function cloudText(d) {
        return d.text;
      }

      function cloudFont() {
        return "serif";
      }

      function cloudFontNormal() {
        return "normal";
      }

      function cloudFontSize(d) {
        return Math.sqrt(d.value);
      }

      function cloudRotate() {
        return (~~(Math.random() * 6) - 3) * 30;
      }

      function cloudPadding() {
        return 1;
      }

      // Fetches a monochrome sprite bitmap for the specified text.
      // Load in batches for speed.
      function cloudSprite(contextAndRatio, d, data, di) {
        if (d.sprite) return;
        var c = contextAndRatio.context,
            ratio = contextAndRatio.ratio;

        c.clearRect(0, 0, (cw << 5) / ratio, ch / ratio);
        var x = 0,
            y = 0,
            maxh = 0,
            n = data.length;
        --di;
        while (++di < n) {
          d = data[di];
          c.save();
          c.font = d.style + " " + d.weight + " " + ~~((d.size + 1) / ratio) + "px " + d.font;
          var w = c.measureText(d.text + "m").width * ratio,
              h = d.size << 1;
          if (d.rotate) {
            var sr = Math.sin(d.rotate * cloudRadians),
                cr = Math.cos(d.rotate * cloudRadians),
                wcr = w * cr,
                wsr = w * sr,
                hcr = h * cr,
                hsr = h * sr;
            w = (Math.max(Math.abs(wcr + hsr), Math.abs(wcr - hsr)) + 0x1f) >> 5 << 5;
            h = ~~Math.max(Math.abs(wsr + hcr), Math.abs(wsr - hcr));
          } else {
            w = (w + 0x1f) >> 5 << 5;
          }
          if (h > maxh) maxh = h;
          if (x + w >= (cw << 5)) {
            x = 0;
            y += maxh;
            maxh = 0;
          }
          if (y + h >= ch) break;
          c.translate((x + (w >> 1)) / ratio, (y + (h >> 1)) / ratio);
          if (d.rotate) c.rotate(d.rotate * cloudRadians);
          c.fillText(d.text, 0, 0);
          if (d.padding) c.lineWidth = 2 * d.padding, c.strokeText(d.text, 0, 0);
          c.restore();
          d.width = w;
          d.height = h;
          d.xoff = x;
          d.yoff = y;
          d.x1 = w >> 1;
          d.y1 = h >> 1;
          d.x0 = -d.x1;
          d.y0 = -d.y1;
          d.hasText = true;
          x += w;
        }
        var pixels = c.getImageData(0, 0, (cw << 5) / ratio, ch / ratio).data,
            sprite = [];
        while (--di >= 0) {
          d = data[di];
          if (!d.hasText) continue;
          var w = d.width,
              w32 = w >> 5,
              h = d.y1 - d.y0;
          // Zero the buffer
          for (var i = 0; i < h * w32; i++) sprite[i] = 0;
          x = d.xoff;
          if (x == null) return;
          y = d.yoff;
          var seen = 0,
              seenRow = -1;
          for (var j = 0; j < h; j++) {
            for (var i = 0; i < w; i++) {
              var k = w32 * j + (i >> 5),
                  m = pixels[((y + j) * (cw << 5) + (x + i)) << 2] ? 1 << (31 - (i % 32)) : 0;
              sprite[k] |= m;
              seen |= m;
            }
            if (seen) seenRow = j;
            else {
              d.y0++;
              h--;
              j--;
              y++;
            }
          }
          d.y1 = d.y0 + seenRow;
          d.sprite = sprite.slice(0, (d.y1 - d.y0) * w32);
        }
      }

      // Use mask-based collision detection.
      function cloudCollide(tag, board, sw) {
        sw >>= 5;
        var sprite = tag.sprite,
            w = tag.width >> 5,
            lx = tag.x - (w << 4),
            sx = lx & 0x7f,
            msx = 32 - sx,
            h = tag.y1 - tag.y0,
            x = (tag.y + tag.y0) * sw + (lx >> 5),
            last;
        for (var j = 0; j < h; j++) {
          last = 0;
          for (var i = 0; i <= w; i++) {
            if (((last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0))
                & board[x + i]) return true;
          }
          x += sw;
        }
        return false;
      }

      function cloudBounds(bounds, d) {
        var b0 = bounds[0],
            b1 = bounds[1];
        if (d.x + d.x0 < b0.x) b0.x = d.x + d.x0;
        if (d.y + d.y0 < b0.y) b0.y = d.y + d.y0;
        if (d.x + d.x1 > b1.x) b1.x = d.x + d.x1;
        if (d.y + d.y1 > b1.y) b1.y = d.y + d.y1;
      }

      function collideRects(a, b) {
        return a.x + a.x1 > b[0].x && a.x + a.x0 < b[1].x && a.y + a.y1 > b[0].y && a.y + a.y0 < b[1].y;
      }

      function archimedeanSpiral(size) {
        var e = size[0] / size[1];
        return function(t) {
          return [e * (t *= .1) * Math.cos(t), t * Math.sin(t)];
        };
      }

      function rectangularSpiral(size) {
        var dy = 4,
            dx = dy * size[0] / size[1],
            x = 0,
            y = 0;
        return function(t) {
          var sign = t < 0 ? -1 : 1;
          // See triangular numbers: T_n = n * (n + 1) / 2.
          switch ((Math.sqrt(1 + 4 * sign * t) - sign) & 3) {
            case 0:  x += dx; break;
            case 1:  y += dy; break;
            case 2:  x -= dx; break;
            default: y -= dy; break;
          }
          return [x, y];
        };
      }

      // TODO reuse arrays?
      function zeroArray(n) {
        var a = [],
            i = -1;
        while (++i < n) a[i] = 0;
        return a;
      }

      function cloudCanvas() {
        return document.createElement("canvas");
      }

      function functor(d) {
        return typeof d === "function" ? d : function() { return d; };
      }

      var spirals = {
        archimedean: archimedeanSpiral,
        rectangular: rectangularSpiral
      }
    }
  }
}