'use strict';

var FrameHandler = require('./FrameHandler');
var GoreHandler = require('./GoreHandler');
var RulerHandler = require('./RulerHandler');
var util = require('./util');

function Viewport(canvas) {
    var _beams = [];
    var _borderWidth = 2;
    var _data = null;
    var _rect;
    var self = this;

    /**
     * Applies viewport to page
     */
    function apply() {
        var cropData = canvas.getImageData().getCropData();
        canvas.remove(_rect);

        _rect = new fabric.Rect({
            evented: false,
            fill: 'transparent',
            width: _data.width,
            height: _data.height,
            stroke: '#fff',
            strokeWidth: canvas.__type === 'canvas' ? 0 : _borderWidth
        });

        _rect.width += _borderWidth;
        _rect.height += _borderWidth;
        _rect.addTo(canvas).center().setCoords();

        if (cropData) {
            // Calculate the new position after screenresize and when the
            // image already has been cropped to a certain position.
            var left = _rect.left + _rect.strokeWidth - (canvas.getImage().width * canvas.getImage().scaleX * cropData.x);
            var top = _rect.top + _rect.strokeWidth - (canvas.getImage().height * canvas.getImage().scaleY * cropData.y);

            canvas.getImage().set({ left: left, top: top }).setCoords();
        } else {
            canvas.getImage().center().setCoords();
        }

        canvas.getImage().drag.enable(calcMinMaxBoundsForRect(_rect.getInsideBoundingRect(), canvas.getImage()))
        canvas.getApertures().apply(_data.axis, _rect.getBoundingRect());

        if (canvas.__type !== 'canvas') {
            drawBeams();
        } else {
            self.setFrame(self.getFrameHandler().getFrameType());
        }

        canvas.getDragbars().apply();
        // Apertures sometimes overlaps the viewports bounding rect.
        // Solve this by bringing it to the front after apertures are applied.
        _rect.bringToFront();
    }

    /**
     * Render the diagonal lines from viewport to edge of the canvas
     */
    function drawBeams() {
        _beams.forEach(function (beam) {
            canvas.remove(beam);
        });

        _beams = [];

        // TOP LEFT
        _beams.push(new fabric.Line(
            [_rect.left, _rect.top, _rect.left - _rect.top, -1], {
                stroke: '#fff',
                strokeWidth: 2,
            }
        ));

        // TOP RIGHT
        _beams.push(_beams[0].clone().set({ flipX: true, left: _rect.left + _rect.width }));
        // BOTTOM RIGHT
        _beams.push(_beams[1].clone().set({ flipY: true, top: _rect.top + _rect.height }));
        // BOTTOM LEFT
        _beams.push(_beams[0].clone().set({ flipY: true, top: _rect.top + _rect.height }));

        _beams.forEach(function (o) {
            canvas.add(o);
            o.bringToFront();
        });
    }

    /**
     * Gets an object with min / max values for each axis, based on the bounds
     * of passed fabric.Rect
     * @param  {fabric.Rect} rect
     * @return {Object}
     */
    function calcMinMaxBoundsForRect(rect, img) {
        return {
            left: {
                min: rect.left + rect.width - (img.width * img.scaleX),
                max: rect.left
            },
            top: {
                min: rect.top + rect.height - (img.height * img.scaleY),
                max: rect.top
            }
        };
    }

    this.canvas = canvas;

    this.getBounds = function () {
        return _rect.getInsideBoundingRect();
    };

    /**
     * @return {Viewport}
     */
    this.reset = function () {
        if (_data) {
            return this.set(_data.dim.width, _data.dim.height, _data.dim.units);
        }
        return this;
    };

    /**
     * @param  {Number} width
     * @param  {Number} height
     * @param  {string} units
     * @return {Viewport}
     */
    this.set = function (width, height, units) {
        var oldData = _data;

        _data = util.calcCrop(canvas.getImage(), width, height, units);

        var keepCropping = (oldData && !util.isAspectChanged(oldData.dim.width, oldData.dim.height, width, height));
        if (keepCropping) {
            canvas.getImageData().setCropData();
        }

        apply();
        this.getGores().reset();
        this.getRulers().reset();

        if (canvas.getImage().__cropped && !keepCropping) {
            canvas.getApertures().setTransparent(true);

            // Trigger event to tell the image needs to be dragged.
            $(document).trigger('PIE:needs-dragging', { axis: _data.axis });
        }

        canvas.getButtonMenu().bringToFront();

    };

    /**
     * @param  {string} frameType white|black|image|none
     * @return {Viewport}
     */
    this.setFrame = function (frameType) {
        this.getFrameHandler().setFrames(frameType);

        var buttons = canvas.getButtonMenu().getItems();
        if (frameType === 'none') {
            buttons[0].setDisabled(true);
        }
        else {
            buttons[0].setDisabled(false);
        }
        canvas.getButtonMenu().bringToFront();

        canvas.refresh3dView();
    };

    this.getData = function () {
        return _data;
    };

    var _frameHandler = null;

    this.getFrameHandler = function () {
        return _frameHandler || (_frameHandler = new FrameHandler(this));
    };

    this.getGores = function () {
        return this.__goreHandler || (this.__goreHandler = new GoreHandler(this));
    };

    this.getRulers = function () {
        return this.__rulerHandler || (this.__rulerHandler = new RulerHandler(this));
    };

}

module.exports = Viewport;