using TriangleNet.Geometry;
using TriangleNet.Topology;

namespace TriangleNet.Meshing.Data
{
	internal class BadTriQueue
	{
		private const double SQRT2 = 1.4142135623730951;

		private BadTriangle[] queuefront;

		private BadTriangle[] queuetail;

		private int[] nextnonemptyq;

		private int firstnonemptyq;

		private int count;

		public int Count => count;

		public BadTriQueue()
		{
			queuefront = new BadTriangle[4096];
			queuetail = new BadTriangle[4096];
			nextnonemptyq = new int[4096];
			firstnonemptyq = -1;
			count = 0;
		}

		public void Enqueue(BadTriangle badtri)
		{
			count++;
			double num;
			int num2;
			if (badtri.key >= 1.0)
			{
				num = badtri.key;
				num2 = 1;
			}
			else
			{
				num = 1.0 / badtri.key;
				num2 = 0;
			}
			int num3 = 0;
			while (num > 2.0)
			{
				int num4 = 1;
				double num5 = 0.5;
				while (num * num5 * num5 > 1.0)
				{
					num4 *= 2;
					num5 *= num5;
				}
				num3 += num4;
				num *= num5;
			}
			num3 = 2 * num3 + ((num > 1.4142135623730951) ? 1 : 0);
			int num6 = ((num2 <= 0) ? (2048 + num3) : (2047 - num3));
			if (queuefront[num6] == null)
			{
				if (num6 > firstnonemptyq)
				{
					nextnonemptyq[num6] = firstnonemptyq;
					firstnonemptyq = num6;
				}
				else
				{
					int i;
					for (i = num6 + 1; queuefront[i] == null; i++)
					{
					}
					nextnonemptyq[num6] = nextnonemptyq[i];
					nextnonemptyq[i] = num6;
				}
				queuefront[num6] = badtri;
			}
			else
			{
				queuetail[num6].next = badtri;
			}
			queuetail[num6] = badtri;
			badtri.next = null;
		}

		public void Enqueue(ref Otri enqtri, double minedge, Vertex apex, Vertex org, Vertex dest)
		{
			BadTriangle badTriangle = new BadTriangle();
			badTriangle.poortri = enqtri;
			badTriangle.key = minedge;
			badTriangle.apex = apex;
			badTriangle.org = org;
			badTriangle.dest = dest;
			Enqueue(badTriangle);
		}

		public BadTriangle Dequeue()
		{
			if (firstnonemptyq < 0)
			{
				return null;
			}
			count--;
			BadTriangle badTriangle = queuefront[firstnonemptyq];
			queuefront[firstnonemptyq] = badTriangle.next;
			if (badTriangle == queuetail[firstnonemptyq])
			{
				firstnonemptyq = nextnonemptyq[firstnonemptyq];
			}
			return badTriangle;
		}
	}
}