import { Vector } from './../../math/Vector2';
import { Vector3 } from './../../math/Vector3';

// Extras / Core /////////////////////////////////////////////////////////////////////

/**
 * An extensible curve object which contains methods for interpolation
 * class Curve<T extends Vector>
 */
export class Curve<T extends Vector> {
	/**
	 * @default 'Curve'
	 */
	type: string;

	/**
	 * This value determines the amount of divisions when calculating the cumulative segment lengths of a curve via .getLengths.
	 * To ensure precision when using methods like .getSpacedPoints, it is recommended to increase .arcLengthDivisions if the curve is very large.
	 * @default 200
	 */
	arcLengthDivisions: number;

	/**
	 * Returns a vector for point t of the curve where t is between 0 and 1
	 * getPoint(t: number, optionalTarget?: T): T;
	 */
	getPoint(t: number, optionalTarget?: T): T;

	/**
	 * Returns a vector for point at relative position in curve according to arc length
	 * getPointAt(u: number, optionalTarget?: T): T;
	 */
	getPointAt(u: number, optionalTarget?: T): T;

	/**
	 * Get sequence of points using getPoint( t )
	 * getPoints(divisions?: number): T[];
	 */
	getPoints(divisions?: number): T[];

	/**
	 * Get sequence of equi-spaced points using getPointAt( u )
	 * getSpacedPoints(divisions?: number): T[];
	 */
	getSpacedPoints(divisions?: number): T[];

	/**
	 * Get total curve arc length
	 */
	getLength(): number;

	/**
	 * Get list of cumulative segment lengths
	 */
	getLengths(divisions?: number): number[];

	/**
	 * Update the cumlative segment distance cache
	 */
	updateArcLengths(): void;

	/**
	 * Given u ( 0 .. 1 ), get a t to find p. This gives you points which are equi distance
	 */
	getUtoTmapping(u: number, distance: number): number;

	/**
	 * Returns a unit vector tangent at t. If the subclassed curve do not implement its tangent derivation, 2 points a
	 * small delta apart will be used to find its gradient which seems to give a reasonable approximation
	 * getTangent(t: number, optionalTarget?: T): T;
	 */
	getTangent(t: number, optionalTarget?: T): T;

	/**
	 * Returns tangent at equidistance point u on the curve
	 * getTangentAt(u: number, optionalTarget?: T): T;
	 */
	getTangentAt(u: number, optionalTarget?: T): T;

	/**
	 * Generate Frenet frames of the curve
	 */
	computeFrenetFrames(
		segments: number,
		closed?: boolean
	): {
		tangents: Vector3[];
		normals: Vector3[];
		binormals: Vector3[];
	};

	clone(): this;
	copy(source: Curve<T>): this;
	toJSON(): object;
	fromJSON(json: object): this;

	/**
	 * @deprecated since r84.
	 */
	static create(constructorFunc: () => void, getPointFunc: () => void): () => void;
}