using System;
using System.Drawing;
using OpenMOBA;
using OpenMOBA.DevTool.Debugging;
using OpenMOBA.Geometry;

namespace QuadSegmentIntersection {
   public class Program {
      // assumes p is ccw ordered
      public static bool SegmentInConvexPolygon(IntLineSegment2 s, IntVector2[] p) {
         var (p1, p2) = s;
         foreach (var (a, b) in p.Zip(p.RotateLeft())) {
            var clock = GeometryOperations.Clockness(p[0], p[1], p[2]);
            if (clock != Clockness.CounterClockwise) throw new BadInputException("p not ccw");
            if (GeometryOperations.Clockness(a, b, p1) == Clockness.Clockwise && GeometryOperations.Clockness(a, b, p2) == Clockness.Clockwise) return false;
         }
         return true;
      }

      public static void Main(string[] args) {
         var bounds = new Size(1280, 720);
         var random = new Random(1);

         IntVector2 RandomPoint() {
            return new IntVector2(random.Next(0, bounds.Width), random.Next(0, bounds.Height));
         }

         IntLineSegment2 RandomSegment() {
            var b = RandomPoint();
            var o = new IntVector2(random.Next(-100, 100), random.Next(-100, 100));
            return new IntLineSegment2(b, b + o);
         }

         var segments = Util.Generate(200, RandomSegment);
         var quad = Util.Generate(4, RandomPoint);
         var hull = GeometryOperations.ConvexHull(quad);

         var host = DebugMultiCanvasHost.CreateAndShowCanvas(bounds, new Point(50, 50), new OrthographicXYProjector());
         var canvas = host.CreateAndAddCanvas(0);
         canvas.BatchDraw(() => {
            // foreach (var (x, y) in quad.Zip(quad.RotateLeft())) canvas.DrawLine(x, y, StrokeStyle.BlackHairLineSolid);
            foreach (var (x, y) in hull.Zip(hull.RotateLeft())) DebugCanvas2DExtensions.DrawLine(canvas, (IntVector2)x, y, StrokeStyle.BlackHairLineSolid);
            foreach (var s in segments) canvas.DrawLine(s.First, s.Second, SegmentInConvexPolygon(s, hull) ? StrokeStyle.LimeHairLineDashed5 : StrokeStyle.RedHairLineDashed5);
         });
      }
   }
}