'use strict';
/* globals $ */

function ImageDataHandler(img) {

    var _cropData;

    /**
     * Gets information about how the cropped image is dragged
     * @return {Object}
     */
    this.getCropData = function () {
        return _cropData;
    };

    this.setCropData = function() {
        var viewportBounds = img.canvas.getViewport().getBounds();
        if (!viewportBounds) {
            return;
        }

        var dragAxis = img.canvas.getViewport().getData().axis;

        var leftDiff = viewportBounds.left - img.left;
        var topDiff = viewportBounds.top - img.top;

        // Robustness measure to handle the extreme precision of shape positioning in canvas.
        var countAsZeroLimit = 1e-5;
        leftDiff = Math.abs(leftDiff) < countAsZeroLimit ? 0 : leftDiff;
        topDiff = Math.abs(topDiff) < countAsZeroLimit ? 0 : topDiff;

        _cropData = {
            x: dragAxis === 'x' ? (leftDiff) / (img.width * img.scaleX) : 0,
            y: dragAxis === 'y' ? (topDiff) / (img.height * img.scaleY) : 0,
            viewportWidth: viewportBounds.width,
            viewportHeight: viewportBounds.height,
        };
    };

    this.removeCropData = function() {
        _cropData = null;
    };

    /**
     * Gets an object containing applied transformations for the Image and also
     * how it is cropped and dragged.
     * @return {Object}
     */
    this.getData = function () {
        var viewportData = img.canvas.getViewport().getData();

        var returnValue = $.extend(
            {},
            {
                mirrored: img.canvas.getMirror().getStatus(),
                width: viewportData.dim.width,
                height: viewportData.dim.height,
            },
            this.getCropData()
        );

        if (img.canvas.__type === 'canvas') {
            var frameHandler = img.canvas.getViewport().getFrameHandler();
            returnValue.edge = frameHandler.getFrameType();
            returnValue.framed = returnValue.edge !== 'none';
        }

        return returnValue;
    };
}

module.exports = ImageDataHandler;