// BasicObstacleSide is base class for an obstacle side that is to the low or high end of the
// scanline-parallel coordinate, and knows which direction to traverse to find the endVertex.
// This is different from RightObstacleSide or LeftObstacleSide, where the class itself is the
// determinant of traversal direction being with or opposite to the clockwise polyline direction;

import {PolylinePoint} from '../../math/geometry/polylinePoint'
import {ObstacleSide} from '../spline/coneSpanner/ObstacleSide'
import {Obstacle} from './obstacle'
import {ScanDirection} from './ScanDirection'
import {StaticGraphUtility} from './StaticGraphUtility'

// BasicObstacleSide uses the ctor arg traverseClockwise to manage that.
export abstract class BasicObstacleSide extends ObstacleSide {
  obstacle: Obstacle
  get Obstacle(): Obstacle {
    return this.obstacle
  }
  set Obstacle(value: Obstacle) {
    this.obstacle = value
  }

  endVertex: PolylinePoint
  Slope = 0
  SlopeInverse = 0

  constructor(obstacle: Obstacle, startVertex: PolylinePoint, scanDir: ScanDirection, traverseClockwise: boolean) {
    super(startVertex)
    this.Obstacle = obstacle
    this.endVertex = traverseClockwise ? startVertex.nextOnPolyline : startVertex.prevOnPolyline
    if (!scanDir.IsPerpendicularPP(startVertex.point, this.endVertex.point)) {
      this.Slope = StaticGraphUtility.Slope(startVertex.point, this.endVertex.point, scanDir)
      this.SlopeInverse = 1 / this.Slope
    }
  }

  get EndVertex(): PolylinePoint {
    return this.endVertex
  }
}

export class LowObstacleSide extends BasicObstacleSide {
  constructor(obstacle: Obstacle, startVertex: PolylinePoint, scanDir: ScanDirection) {
    super(obstacle, startVertex, scanDir, scanDir.IsHorizontal)
  }
}
export class HighObstacleSide extends BasicObstacleSide {
  constructor(obstacle: Obstacle, startVertex: PolylinePoint, scanDir: ScanDirection) {
    super(obstacle, startVertex, scanDir, scanDir.IsVertical)
  }
}