import {LineSegment} from '../../math/geometry/lineSegment'
import {Point, TriangleOrientation} from '../../math/geometry/point'
import {Polyline} from '../../math/geometry/polyline'
import {PolylinePoint} from '../../math/geometry/polylinePoint'

import {BimodalSequence} from './BimodalSequence'
import {TangentPair} from './TangentPair'

export class Polygon {
  private polyline: Polyline
  static mkFromPoints(pts: Point[]): Polygon {
    return new Polygon(Polyline.mkClosedFromPoints(pts))
  }

  get Polyline(): Polyline {
    return this.polyline
  }

  points: PolylinePoint[]

  constructor(polyline: Polyline) {
    this.polyline = polyline
    this.points = new Array<PolylinePoint>()
    for (let pp = this.polyline.startPoint; pp; pp = pp.next) this.points.push(pp)
    /*Assert.assert(
      polyline.count < 3 ||
        Point.getTriangleOrientation(this.pnt(0), this.pnt(1), this.pnt(2)) !=
          TriangleOrientation.Counterclockwise,
    )*/
  }

  Next(i: number): number {
    return this.Module(i + 1)
  }

  Prev(i: number): number {
    return this.Module(i - 1)
  }

  get count(): number {
    return this.Polyline.count
  }

  Module(i: number): number {
    if (i < 0) {
      return i + this.count
    }

    if (i < this.count) {
      return i
    }
    return i - this.count
  }

  pp(i: number): PolylinePoint {
    return this.points[this.Module(i)]
  }

  // LineSegment ls(Point pivot, int p) {
  //    return new LineSegment(pivot, Pnt(p));
  // }
  pnt(i: number): Point {
    return this.pp(i).point
  }

  public toString(): string {
    return this.polyline.toString()
  }

  // the median of a chunk going clockwise from p1 to p2
  Median(p1: number, p2: number): number {
    /*Assert.assert(p1 !== p2)*/
    // otherwise we do not know what arc is mean: the whole one or just the point
    if (p2 > p1) {
      return Math.floor((p2 + p1) / 2)
    }

    return this.Module(p2 + Math.floor((this.count + p1) / 2))
  }

  // p1 and p2 represent the closest feature. Two cases are possible p1=p2, or p1 and p2 share an edge going from p1 to p2
  // Remind that the polygons are oriented clockwise
  FindTheFurthestVertexFromBisector(p1: number, p2: number, bisectorPivot: Point, bisectorRay: Point): number {
    let directionToTheHill: Point = bisectorRay.rotate(Math.PI / 2)
    if (this.polyline.startPoint.point.sub(bisectorPivot).dot(directionToTheHill) < 0) {
      directionToTheHill = directionToTheHill.mul(-1)
    }

    if (p1 === p2) {
      p2 = this.Next(p1)
    }

    // binary search
    do {
      const m: number = this.Median(p2, p1)
      // now the chunk goes clockwise from p2 to p1
      const mp: Point = this.pnt(m)
      if (this.pnt(this.Next(m)).sub(mp).dot(directionToTheHill) >= 0) {
        p2 = this.Next(m)
      } else if (this.pnt(this.Prev(m)).sub(mp).dot(directionToTheHill) >= 0) {
        p1 = this.Prev(m)
      } else {
        p2 = m
      }

      p1 = m
    } while (p1 !== p2)

    return p1
  }

  static TestPolygonDist(a: Polygon, b: Polygon): number {
    let ret: number = Number.MAX_SAFE_INTEGER
    for (let i = 0; i < a.count; i++) {
      for (let j = 0; j < b.count; j++) {
        const t = LineSegment.minDistBetweenLineSegments(a.pnt(i), a.pnt(i + 1), b.pnt(j), b.pnt(j + 1))
        ret = Math.min(ret, t.dist)
      }
    }
    return ret
  }

  // Distance between two polygons
  // p and q are the closest points
  // The function doesn't work if the polygons intersect each other
  static Distance(a: Polygon, b: Polygon): {p: Point; q: Point; dist: number} {
    const tp = new TangentPair(a, b)
    const pq = tp.FindClosestPoints()
    //    #if(TEST_MSAGL)
    // if (!Point.closeDistEps((p - q).length, Polygon.TestPolygonDist(a, b))) {
    //  let stream = File.Open("c:\tmp\polygonBug", FileMode.Create);
    //  let bf = new BinaryFormatter();
    //  bf.Serialize(stream, a);
    //  bf.Serialize(stream, b);
    //  LayoutAlgorithmSettings.ShowDebugCurves(new DebugCurve(100, 0.1, "red", a.Polyline), new DebugCurve(100, 0.1, "blue", b.Polyline), new DebugCurve(100, 0.1, "black", new LineSegment(p, q)));
    //  System.Diagnostics.Debug.Fail("wrong distance between two polygons");
    // }

    //    #endif
    return {
      p: pq.pClosest,
      q: pq.qClosest,
      dist: pq.pClosest.sub(pq.qClosest).length,
    }
  }

  // Distance between two polygons
  static DistanceOnly(a: Polygon, b: Polygon): number {
    /*Assert.assert(Polygon.PolygonIsLegalDebug(a))*/
    /*Assert.assert(Polygon.PolygonIsLegalDebug(b))*/
    return Polygon.Distance(a, b).dist
  }

  static PolygonIsLegalDebug(a: Polygon): boolean {
    const poly = a.Polyline
    for (let p = poly.startPoint; p.next != null && p.next.next != null; p = p.next) {
      if (Point.getTriangleOrientation(p.point, p.next.point, p.next.next.point) === TriangleOrientation.Collinear) {
        return false
      }
    }

    return true
  }

  // Distance between polygon and point, assuming the point is outside of the polygon
  static DistancePoint(poly: Polygon, b: Point): number {
    let res = Number.MAX_VALUE
    for (let i = 0; i < poly.count; i++) {
      const dist = Point.distToLineSegment(b, poly.points[i].point, poly.points[(i + 1) % poly.count].point).dist

      res = Math.min(res, dist)
    }

    return res
  }

  GetTangentPoints(t: {leftTangentPoint: number; rightTangentPoint: number}, point: Point) {
    const bimodalSequence = new BimodalSequence(this.GetSequenceDelegate(point), this.count)
    t.leftTangentPoint = bimodalSequence.FindMaximum()
    t.rightTangentPoint = bimodalSequence.FindMinimum()
  }

  GetSequenceDelegate(point: Point): (u: number) => number {
    const pointOfP = this.pnt(0)
    return (i: number) => {
      const d = Point.anglePCP(pointOfP, point, this.pnt(i))
      return d < Math.PI ? d : d - 2 * Math.PI
    }
  }
}