/**
 *
 */
var BubbleSort = function() {
    //===== Action management.
    //
    this.preSort = function(arr) {
        this
            .instruct(Itemgroup.background, 1, 0, 0, arr.length, Visualizer.bg0)

            .instruct(Itemgroup.message, 0, 0, 1, `Comparisons: ${this.comparisons}`)
            .instruct(Itemgroup.message, 0, 0, 2, `Swaps: ${this.swaps}`)
            .instruct(Itemgroup.message, 0, 0, 3, ``)
            .instruct(Itemgroup.message, 0, 0, 4, ``)
            .instruct(Itemgroup.message, 0, 100, 5, `Starting sort.`)
    };

    //
    this.midSort = function(arr, i) {
        this
            .instruct(Itemgroup.background, 1, 0, 0, arr.length, Visualizer.bg0)
            .instruct(Itemgroup.background, 1, 0, i, i, Visualizer.bg1)
            .instruct(Itemgroup.background, 1, 0, (i - 1), (i - 1), Visualizer.bg1)

            .instruct(Itemgroup.message, 0, 0, 1, `Comparisons: ${this.comparisons}`)
            .instruct(Itemgroup.message, 0, 0, 3, `Comparing ${arr[i - 1]} and ${arr[i]}.`)
            .instruct(Itemgroup.message, 0, 0, 4, ``)
            .instruct(Itemgroup.message, 0, 100, 5, ``)
    };

    //
    this.swap = function(arr, i) {
        this
            .instruct(Itemgroup.background, 1, 0, 0, arr.length, Visualizer.bg0)
            .instruct(Itemgroup.background, 1, 0, i, i, Visualizer.bg1)
            .instruct(Itemgroup.background, 1, 0, (i - 1), (i - 1), Visualizer.bg1)

            .instruct(Itemgroup.message, 0, 0, 2, `Swaps: ${this.swaps}`)
            .instruct(Itemgroup.message, 0, 0, 4, `${arr[i]} > ${arr[i - 1]}`)
            .instruct(Itemgroup.message, 0, 0, 5, `Swap current and previous.`)
            .instruct(Itemgroup.swap, 1, 300, i, i - 1)
    };

    //
    this.foundSwapped = function(arr) {
        this
            .instruct(Itemgroup.background, 1, 0, 0, arr.length, Visualizer.bg0)

            .instruct(Itemgroup.message, 0, 0, 3, ``)
            .instruct(Itemgroup.message, 0, 0, 4, `Swapped elements found.`)
            .instruct(Itemgroup.message, 0, 100, 5, `Recursing.`)
    };

    //
    this.postSort = function(arr) {
        this
            .instruct(Itemgroup.background, 1, 0, 0, arr.length, Visualizer.bg0)

            .instruct(Itemgroup.message, 0, 0, 1, `Comparisons: ${this.comparisons}`)
            .instruct(Itemgroup.message, 0, 0, 2, `Swaps: ${this.swaps}`)
            .instruct(Itemgroup.message, 0, 0, 3, ``)
            .instruct(Itemgroup.message, 0, 0, 4, ``)
            .instruct(Itemgroup.message, 0, 100, 5, `Sorting complete.`)
    };
};

BubbleSort.prototype = Object.create(Sorter.prototype);

/**
 *
 */
BubbleSort.prototype.init = function() {
    var len = this.shuffled.length;

    this.actions = [];
    this.swaps = 0;
    this.comparisons = 0;

    this
        .instruct(Itemgroup.items, 0, 0, len)
        .instruct(Itemgroup.items, 1, 0, len)
        .instruct(Itemgroup.items, 2, 0, len)

    for (var i = 0; i < len; i++) {
        this.instruct(Itemgroup.text, 1, 0, i, this.shuffled[i]);
    }

    this
        .instruct(Itemgroup.foreground, 1, 0, 0, len, Visualizer.fg0)
        .instruct(Itemgroup.background, 1, 0, 0, len, Visualizer.bg0)

        .instruct(Itemgroup.opacity, 0, 0, 0, len, 0)
        .instruct(Itemgroup.opacity, 2, 0, 0, len, 0)
};

/**
 *
 */
BubbleSort.prototype.sort = function(arr) {
    var i, tmp;
    var swapped = false;
    var len = arr.length;

    this.preSort(arr);

    for (i = 1; i < len; i++) {
        this.comparisons++;
        this.midSort(arr, i);

        if (arr[i - 1] > arr[i]) {
            this.swaps++;

            tmp = arr[i];
            arr[i] = arr[i - 1];
            arr[i - 1] = tmp;

            swapped = true;

            this.swap(arr, i, i - 1);
        }
    }

    if (swapped === true) {
        this.foundSwapped(arr);
        this.sort(arr);
    }

    this.postSort(arr);

    return arr;
};