import {String} from 'typescript-string-operations'

import {Cdt} from './Cdt'
import {CdtSite} from './CdtSite'
import {CdtTriangle} from './CdtTriangle'

export class CdtEdge {
  public upperSite: CdtSite

  public lowerSite: CdtSite

  /**  in this triangle the edge goes counterclockwise*/
  private ccwTriangle: CdtTriangle

  /** in this triangle the edge goes clockwise, against the triangle orientation */
  private cwTriangle: CdtTriangle

  // is an obstacle side, or a given segment
  public constrained = false

  public constructor(a: CdtSite, b: CdtSite) {
    const above = Cdt.AbovePP(a.point, b.point)
    if (above === 1) {
      this.upperSite = a
      this.lowerSite = b
    } else {
      /*Assert.assert(above !== 0)*/
      this.lowerSite = a
      this.upperSite = b
    }

    this.upperSite.AddEdgeToSite(this)
  }

  // the amount of free space around the edge
  Capacity = 1000000

  // the amount of residual free space around the edge
  ResidualCapacity: number
  public get CcwTriangle(): CdtTriangle {
    return this.ccwTriangle
  }
  public set CcwTriangle(value: CdtTriangle) {
    /*Assert.assert(
      value == null  ||
        this.cwTriangle == null  ||
        value.OppositeSite(this) !== this.cwTriangle.OppositeSite(this),
    )*/
    this.ccwTriangle = value
  }

  public get CwTriangle(): CdtTriangle {
    return this.cwTriangle
  }
  public set CwTriangle(value: CdtTriangle) {
    /*Assert.assert(
      value == null  ||
        this.ccwTriangle == null  ||
        value.OppositeSite(this) !== this.ccwTriangle.OppositeSite(this),
    )*/
    this.cwTriangle = value
  }

  // returns the trianlge on the edge opposite to the site
  public GetOtherTriangle_c(p: CdtSite): CdtTriangle {
    return this.cwTriangle.Contains(p) ? this.ccwTriangle : this.cwTriangle
  }

  public IsAdjacent(pi: CdtSite): boolean {
    return pi === this.upperSite || pi === this.lowerSite
  }

  public GetOtherTriangle_T(triangle: CdtTriangle): CdtTriangle {
    return this.ccwTriangle === triangle ? this.cwTriangle : this.ccwTriangle
  }

  // A string that represents the current object.
  public toString(): string {
    return String.format('({0},{1})', this.upperSite, this.lowerSite)
  }

  public OtherSite(site: CdtSite): CdtSite {
    /*Assert.assert(this.IsAdjacent(site))*/
    return this.upperSite === site ? this.lowerSite : this.upperSite
  }
}