/**
 * @author  Ikaros Kappler
 * @version 1.0.0
 * @date    2022-10-17
 */

import { Path, PathSegment } from "../../interfaces/additionals";
import { Vertex } from "../../Vertex";

export class GenericPath implements Path {
  segments: Array<PathSegment>;

  constructor(startSegment: PathSegment) {
    this.segments = [startSegment];
  }

  /**
   * Get the number of segments in this path.
   *
   * @method getSegmentCount
   * @memberof Path
   * @return {number} The number (integer) of path segments.
   */
  getSegmentCount(): number {
    return this.segments.length;
  }

  /**
   * 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 {
    return this.segments[index];
  }

  /**
   * Create a deep clone of this path.
   *
   * @method clone
   * @memberof Path
   * @return {Path} A deep clone/copy of this path.
   */
  clone(): GenericPath {
    const newPath = new GenericPath(this.segments[this.segments.length - 1].clone().reverse());
    for (var i = this.segments.length - 2; i >= 0; i--) {
      newPath.segments.push(this.segments[i].clone().reverse());
    }
    return newPath;
  }

  /**
   * Reverse this path (swap start and end and thus – the direction) in-place.
   *
   * @method reverse
   * @memberof Path
   * @return {PathSegment} This path instance.
   */
  reverse() {
    const newSegments: Array<PathSegment> = [];
    for (var i = this.segments.length - 1; i >= 0; i--) {
      newSegments.push(this.segments[i].reverse());
    }
    this.segments = newSegments;
    return this;
  }

  /**
   * Get the start point of this path segment.
   *
   * @method getStartPoint
   * @memberof PathSegment
   * @return {Vertex} The start point of this path segment.
   */
  getStartPoint(): Vertex {
    return this.segments[0].getStartPoint();
  }

  /**
   * Get the end point of this path segment.
   *
   * @method getEndPoint
   * @memberof PathSegment
   * @return {Vertex} The end point of this path segment.
   */
  getEndPoint(): Vertex {
    return this.segments[this.segments.length - 1].getEndPoint();
  }

  /**
   * 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 {
    return this.segments[0].getStartTangent();
  }

  /**
   * 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 {
    return this.segments[this.segments.length - 1].getEndTangent();
  }
}