using System;
using UnityEngine;

namespace RMGUI.GraphView
{
	internal class RectUtils
	{
		public static bool IntersectsSegment(Rect rect, Vector2 p1, Vector2 p2)
		{
			float minX = Mathf.Min(p1.x, p2.x);
			float maxX = Mathf.Max(p1.x, p2.x);

			if (maxX > rect.xMax)
			{
				maxX = rect.xMax;
			}

			if (minX < rect.xMin)
			{
				minX = rect.xMin;
			}

			if (minX > maxX)
			{
				return false;
			}

			float minY = Mathf.Min(p1.y, p2.y);
			float maxY = Mathf.Max(p1.y, p2.y);

			float dx = p2.x - p1.x;

			if (Mathf.Abs(dx) > float.Epsilon)
			{
				float a = (p2.y - p1.y) / dx;
				float b = p1.y - a * p1.x;
				minY = a * minX + b;
				maxY = a * maxX + b;
			}

			if (minY > maxY)
			{
				float tmp = maxY;
				maxY = minY;
				minY = tmp;
			}

			if (maxY > rect.yMax)
			{
				maxY = rect.yMax;
			}

			if (minY < rect.yMin)
			{
				minY = rect.yMin;
			}

			if (minY > maxY)
			{
				return false;
			}

			return true;
		}

		public static Rect Encompass(Rect a, Rect b)
		{
			return new Rect
			{
				xMin = Math.Min(a.xMin, b.xMin),
				yMin = Math.Min(a.yMin, b.yMin),
				xMax = Math.Max(a.xMax, b.xMax),
				yMax = Math.Max(a.yMax, b.yMax)
			};
		}
	}
}