require("../env");

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

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

var vows = require("vows"),

    assert = require("assert");

var suite = vows.describe("d3.layout.histogram");

suite.addBatch({

  "histogram": {

    topic: function() {

      return d3.layout.histogram;

    },

    "defaults to frequencies": function(histogram) {

      var h = histogram();

      assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [[0, 0, 0], [], [1], [2, 2]]);

    },

    "each bin contains the matching source elements": function(histogram) {

      var h = histogram();

      assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [[0, 0, 0], [], [1], [2, 2]]);

    },

    "each bin also has defined x, y and dx properties": function(histogram) {

      var h = histogram();

      assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [

        {x:   0, y: 3, dx: 0.5},

        {x: 0.5, y: 0, dx: 0.5},

        {x:   1, y: 1, dx: 0.5},

        {x: 1.5, y: 2, dx: 0.5}

      ]);

    },

    "can output frequencies": function(histogram) {

      var h = histogram().frequency(true);

      assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [

        {x:   0, y: 3, dx: 0.5},

        {x: 0.5, y: 0, dx: 0.5},

        {x:   1, y: 1, dx: 0.5},

        {x: 1.5, y: 2, dx: 0.5}

      ]);

    },

    "can output probabilities": function(histogram) {

      var h = histogram().frequency(false);

      assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [

        {x:   0, y: 3/6, dx: 0.5},

        {x: 0.5, y:   0, dx: 0.5},

        {x:   1, y: 1/6, dx: 0.5},

        {x: 1.5, y: 2/6, dx: 0.5}

      ]);

    },

    "can specify number of bins": function(histogram) {

      var h = histogram().bins(2);

      assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [

        [0, 0, 0],

        [1, 2, 2]

      ]);

      assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [

        {x: 0, y: 3, dx: 1},

        {x: 1, y: 3, dx: 1}

      ]);

    },

    "can specify bin thresholds": function(histogram) {

      var h = histogram().bins([0,1,2,3]);

      assert.deepEqual(h([0,0,0,1,2,2]).map(elements), [

        [0, 0, 0],

        [1],

        [2, 2]

      ]);

      assert.deepEqual(h([0,0,0,1,2,2]).map(metadata), [

        {x: 0, y: 3, dx: 1},

        {x: 1, y: 1, dx: 1},

        {x: 2, y: 2, dx: 1}

      ]);

    }

  }

});

function elements(bin) {

  var array = [], i = -1, n = bin.length;

  while (++i < n) array.push(bin[i]);

  return array;

}

function metadata(bin) {

  var metadata = {};

  if ("x" in bin) metadata.x = bin.x;

  if ("y" in bin) metadata.y = bin.y;

  if ("dx" in bin) metadata.dx = bin.dx;

  return metadata;

}

suite.export(module);