/*!
 * Copyright (c) 2024, Oracle and/or its affiliates.
 */

/**
 * @file
 * 
 * Extended joint.linkTools.Segments with additional functionality and/or overrides.
 * 
 * Adds handles above links to be able to reposition a link segment. This can lead to creation
 * and/or repositioning of new vertices.
 */

const { linkTools, util } = joint;

export default class Segments extends linkTools.Segments {

    #linkBeforeChangeInitialProps;

    // Override to save the original link props
    onHandleChangeStart( handle, e ) {
        const { relatedView: linkView } = this;
        const { model } = linkView;
        this.#linkBeforeChangeInitialProps = {
            vertices: model.vertices(),
            source: util.cloneDeep( model.source() ),
            target: util.cloneDeep( model.target() )
        };
        super.onHandleChangeStart( handle, e );
    }

    // Override to dispatch a custom event with new & original link props
    onHandleChangeEnd( handle, e ) {
        const { relatedView: linkView } = this;
        const { model } = linkView;

        super.onHandleChangeEnd( handle, e );

        const [normalizedEvt, x, y] = linkView.paper.getPointerArgs( e );
        const ori = this.#linkBeforeChangeInitialProps;
        const curr = {
            vertices: model.vertices(),
            source: model.source(),
            target: model.target()
        };
        const changes = [];
        const newValues = {};
        const oldValues = {};

        if ( ( curr.vertices.length !== ori.vertices.length ) || ( curr.vertices.length && !util.isEqual( curr.vertices, ori.vertices ) ) ) {
            changes.push( "vertices" );
        }
        // target and/or source may have changed
        if ( !util.isEqual( curr.source, ori.source ) ) {
            changes.push( "source" );
        }
        if ( !util.isEqual( curr.target, ori.target ) ) {
            changes.push( "target" );
        }

        changes.forEach( change => {
            newValues[change] = curr[change];
            oldValues[change] = ori[change];
        } );
        this.#linkBeforeChangeInitialProps = null;

        linkView.notify( "link:segmenthandle:pointerup", this, handle, newValues, oldValues, normalizedEvt, x, y );
    }
}