/**
 *
 */
function Visualizer(parent) {
    this.parent = parent;
    this.sorter = null;
    this.paused = true;

    var sorterSidebarContainer = document.createElement('div');
    sorterSidebarContainer.className = 'sorter-sidebar';
    parent.appendChild(sorterSidebarContainer);

    var properties = this.initProperties();
    parent.appendChild(properties);

    var controls = this.initControls();
    parent.querySelector('.sorter-sidebar').appendChild(controls);

    var messages = this.initMessages();
    parent.querySelector('.sorter-sidebar').appendChild(messages);

    var range = this.initRange();
    parent.querySelector('.sorter-sidebar').appendChild(range);

    switch(parent.attributes['data-algorithm'].value) {
        case 'quick':
            this.sorter = new QuickSort();
            break;

        case 'merge':
            this.sorter = new MergeSort();
            break;

        case 'selection':
            this.sorter = new SelectionSort();
            break;

        case 'bubble':
            this.sorter = new BubbleSort();
            break;

        case 'insertion':
            this.sorter = new InsertionSort();
            break;

        case 'shell':
            this.sorter = new ShellSort();
            break;

        case 'radix':
            this.sorter = new RadixSort();
            break;

        default:
            throw new Error('Unrecognized sort type.');
    }

    this.initItems(10);
};

// Public static properties (mutable)
Visualizer.spacerW  = 5;
Visualizer.itemW    = 14;
Visualizer.itemH    = 50;
Visualizer.itemY    = 20;

/**
 *
 */
Visualizer.calculateX = function(index) {
    return Visualizer.spacerW + index * (Visualizer.itemW + Visualizer.spacerW)
};

/**
 * Instructions contain a string with the name of a function in this object which is called to perform an action.
 */
Visualizer.prototype.followInstruction = function() {
    if (this.instructionIndex >= this.sorter.instructions.length) {
        return;
    }

    var instruction = this.sorter.instructions[this.instructionIndex];
    var operation = this[instruction[0]];
    var delay = instruction[1];

    console.log(instruction);

    // NOTE interesting (anti?)pattern here.
    // NOTE use of call() vs apply() (apply only delivered first array item as string)
    if (typeof operation === 'function') {
        operation.call(this, instruction);

        if (this.paused === false) {
            this.instructionIndex++;
            setTimeout(this.followInstruction.bind(this), delay);
        }
    }
    else {
        console.error(i);
        throw new Error('Unidentified instruction.');
    }
};