import { Curve } from '../core/Curve.js';
import { CatmullRom } from '../core/Interpolations.js';
import { Vector2 } from '../../math/Vector2.js';

class SplineCurve extends Curve {

	constructor( points = [] ) {

		super();

		this.type = 'SplineCurve';

		this.points = points;

	}

	getPoint( t, optionalTarget = new Vector2() ) {

		const point = optionalTarget;

		const points = this.points;
		const p = ( points.length - 1 ) * t;

		const intPoint = Math.floor( p );
		const weight = p - intPoint;

		const p0 = points[ intPoint === 0 ? intPoint : intPoint - 1 ];
		const p1 = points[ intPoint ];
		const p2 = points[ intPoint > points.length - 2 ? points.length - 1 : intPoint + 1 ];
		const p3 = points[ intPoint > points.length - 3 ? points.length - 1 : intPoint + 2 ];

		point.set(
			CatmullRom( weight, p0.x, p1.x, p2.x, p3.x ),
			CatmullRom( weight, p0.y, p1.y, p2.y, p3.y )
		);

		return point;

	}

	copy( source ) {

		super.copy( source );

		this.points = [];

		for ( let i = 0, l = source.points.length; i < l; i ++ ) {

			const point = source.points[ i ];

			this.points.push( point.clone() );

		}

		return this;

	}

	toJSON() {

		const data = super.toJSON();

		data.points = [];

		for ( let i = 0, l = this.points.length; i < l; i ++ ) {

			const point = this.points[ i ];
			data.points.push( point.toArray() );

		}

		return data;

	}

	fromJSON( json ) {

		super.fromJSON( json );

		this.points = [];

		for ( let i = 0, l = json.points.length; i < l; i ++ ) {

			const point = json.points[ i ];
			this.points.push( new Vector2().fromArray( point ) );

		}

		return this;

	}

}

SplineCurve.prototype.isSplineCurve = true;

export { SplineCurve };
