/**
 * @date 2022-10-17
 */
import { Vertex } from "../Vertex";

/**
 * A common interface for different kinds of path segments.
 */
export interface PathSegment {
  /**
   * Get the start point of this path segment.
   *
   * @method getStartPoint
   * @memberof PathSegment
   * @return {Vertex} The start point of this path segment.
   */
  getStartPoint(): Vertex;

  /**
   * Get the end point of this path segment.
   *
   * @method getEndPoint
   * @memberof PathSegment
   * @return {Vertex} The end point of this path segment.
   */
  getEndPoint(): Vertex;

  /**
   * Get the tangent's end point at the start point of this segment.
   *
   * @method getStartTangent
   * @memberof PathSegment
   * @return {Vertex} The end point of the starting point's tangent.
   */
  getStartTangent(): Vertex;

  /**
   * Get the tangent's end point at the end point of this segment.
   *
   * @method getEndTangent
   * @memberof PathSegment
   * @return {Vertex} The end point of the ending point's tangent.
   */
  getEndTangent(): Vertex;

  /**
   * Create a deep clone of this path segment.
   *
   * @method clone
   * @memberof PathSegment
   * @return {PathSegment} A deep clone/copy of this path segment.
   */
  clone: () => PathSegment;

  /**
   * Revserse this path segment (in-place) and return this same instance (useful for chaining).
   * The new path segment has start and end point swapped.
   *
   * @method reverse
   * @memberof PathSegment
   * @return {PathSegment} This path segment instance (for chaining).
   */
  reverse: () => PathSegment;
}

/**
 * A common interface for general path representations.
 */
export interface Path extends PathSegment {
  /**
   * Get the number of segments in this path.
   *
   * @method getSegmentCount
   * @memberof Path
   * @return {number} The number (integer) of path segments.
   */
  getSegmentCount: () => number;

  /**
   * Get the path segment at the given index.
   *
   * @method getSegmentAt
   * @memberof Path
   * @return {PathSegment} The paths segment at the given index.
   */
  getSegmentAt: (index: number) => PathSegment;

  /**
   * Create a deep clone of this path.
   *
   * @method clone
   * @memberof Path
   * @return {Path} A deep clone/copy of this path.
   */
  clone: () => Path;

  /**
   * Reverse this path (swap start and end and thus – the direction) in-place.
   *
   * @method revert
   * @memberof Path
   * @return {PathSegment} This path instance.
   */
  reverse: () => Path;
}