// namespaces
var dwv = dwv || {};
dwv.tool = dwv.tool || {};
// external
var Konva = Konva || {};

/**
 * Ellipse factory.
 * @constructor
 * @external Konva
 */
dwv.tool.EllipseFactory = function ()
{
    /**
     * Get the number of points needed to build the shape.
     * @return {Number} The number of points.
     */
    this.getNPoints = function () { return 2; };
    /**
     * Get the timeout between point storage.
     * @return {Number} The timeout in milliseconds.
     */
    this.getTimeout = function () { return 0; };
};

/**
 * Create an ellipse shape to be displayed.
 * @param {Array} points The points from which to extract the ellipse.
 * @param {Object} style The drawing style.
 * @param {Object} image The associated image.
 */
dwv.tool.EllipseFactory.prototype.create = function (points, style, image)
{
    // calculate radius
    var a = Math.abs(points[0].getX() - points[1].getX());
    var b = Math.abs(points[0].getY() - points[1].getY());
    // physical shape
    var ellipse = new dwv.math.Ellipse(points[0], a, b);
    // draw shape
    var kshape = new Konva.Ellipse({
        x: ellipse.getCenter().getX(),
        y: ellipse.getCenter().getY(),
        radius: { x: ellipse.getA(), y: ellipse.getB() },
        stroke: style.getLineColour(),
        strokeWidth: style.getScaledStrokeWidth(),
        name: "shape"
    });
    // quantification
    var quant = image.quantifyEllipse( ellipse );
    var ktext = new Konva.Text({
        fontSize: style.getScaledFontSize(),
        fontFamily: style.getFontFamily(),
        fill: style.getLineColour(),
        name: "text"
    });
    ktext.textExpr = "{surface}";
    ktext.longText = "";
    ktext.quant = quant;
    ktext.setText(dwv.utils.replaceFlags(ktext.textExpr, ktext.quant));
    // label
    var klabel = new Konva.Label({
        x: ellipse.getCenter().getX(),
        y: ellipse.getCenter().getY(),
        name: "label"
    });
    klabel.add(ktext);
    klabel.add(new Konva.Tag());

    // return group
    var group = new Konva.Group();
    group.name("ellipse-group");
    group.add(kshape);
    group.add(klabel);
    group.visible(true); // dont inherit
    return group;
};

/**
 * Update an ellipse shape.
 * @param {Object} anchor The active anchor.
 * @param {Object} image The associated image.
 */
dwv.tool.UpdateEllipse = function (anchor, image)
{
    // parent group
    var group = anchor.getParent();
    // associated shape
    var kellipse = group.getChildren( function (node) {
        return node.name() === 'shape';
    })[0];
    // associated label
    var klabel = group.getChildren( function (node) {
        return node.name() === 'label';
    })[0];
    // find special points
    var topLeft = group.getChildren( function (node) {
        return node.id() === 'topLeft';
    })[0];
    var topRight = group.getChildren( function (node) {
        return node.id() === 'topRight';
    })[0];
    var bottomRight = group.getChildren( function (node) {
        return node.id() === 'bottomRight';
    })[0];
    var bottomLeft = group.getChildren( function (node) {
        return node.id() === 'bottomLeft';
    })[0];
    // update 'self' (undo case) and special points
    switch ( anchor.id() ) {
    case 'topLeft':
        topLeft.x( anchor.x() );
        topLeft.y( anchor.y() );
        topRight.y( anchor.y() );
        bottomLeft.x( anchor.x() );
        break;
    case 'topRight':
        topRight.x( anchor.x() );
        topRight.y( anchor.y() );
        topLeft.y( anchor.y() );
        bottomRight.x( anchor.x() );
        break;
    case 'bottomRight':
        bottomRight.x( anchor.x() );
        bottomRight.y( anchor.y() );
        bottomLeft.y( anchor.y() );
        topRight.x( anchor.x() );
        break;
    case 'bottomLeft':
        bottomLeft.x( anchor.x() );
        bottomLeft.y( anchor.y() );
        bottomRight.y( anchor.y() );
        topLeft.x( anchor.x() );
        break;
    default :
        console.error('Unhandled anchor id: '+anchor.id());
        break;
    }
    // update shape
    var radiusX = ( topRight.x() - topLeft.x() ) / 2;
    var radiusY = ( bottomRight.y() - topRight.y() ) / 2;
    var center = { 'x': topLeft.x() + radiusX, 'y': topRight.y() + radiusY };
    kellipse.position( center );
    var radiusAbs = { 'x': Math.abs(radiusX), 'y': Math.abs(radiusY) };
    if ( radiusAbs ) {
        kellipse.radius( radiusAbs );
    }
    // new ellipse
    var ellipse = new dwv.math.Ellipse(center, radiusAbs.x, radiusAbs.y);
    // update text
    var quant = image.quantifyEllipse( ellipse );
    var ktext = klabel.getText();
    ktext.quant = quant;
    ktext.setText(dwv.utils.replaceFlags(ktext.textExpr, ktext.quant));
    // update position
    var textPos = { 'x': center.x, 'y': center.y };
    klabel.position( textPos );
};