'use strict';

function GoreHandler(viewport) {
    var _enabled = false;
    var _lines = [];

    /**
     * @return {fabric.Line}
     */
    function getLine(left) {
        return new fabric.Line([0, 0, 0, viewport.getData().height], {
            evented: false,
            strokeDashArray: [5, 5],
            stroke: '#000',
            strokeWidth: 1,
            left: left,
            top: viewport.getBounds().top
        });
    }

    /**
     * @return {GoreHandler}
     */
    this.clear = function () {
        _lines.forEach(function (line) {
            viewport.canvas.remove(line);
        });
        _lines = [];
        return this;
    };

    /**
     * @param  {Boolean} enabled
     * @return {GoreHandler}
     */
    this.enable = function (enabled) {
        _enabled = enabled;
        this.clear();

        if (!_enabled) {
            viewport.canvas.renderAll();
            return;
        }

        var bounds = viewport.getBounds();
        var step   = viewport.getData().ppmm * 450;
        var count  = Math.ceil(bounds.width / step);

        for (var i = 1; i < count; i++) {
            _lines.push(getLine(bounds.left + step * i));
        }

        _lines.forEach(function (o) {
            viewport.canvas.add(o);
        });

        viewport.canvas.renderAll();

        return this;
    };

    /**
     * @return {GoreHandler}
     */
    this.reset = function () {
        return this.enable(_enabled);
    };
}

module.exports = GoreHandler;