using UnityEditor;
using UnityEngine;

namespace XRLib
{
    public static class Wathf
    {
        /// <summary>
        /// 1.618 : 1 = x : y
        /// ex) standard = 3
        /// result[0] = f(x==standard)
        /// result[1] = f(y==standard)
        /// </summary>
        /// <param name="standard"></param>
        /// <param name="result"></param>
        public static void GoldenRatio(float standard, out float[] result)
        {
            result = new float[2];
            result[0] = standard * 1.618f;
            result[1] = standard * 0.618f;
        }


        public static bool GetCrossVector(Vector3[] a, Vector3[] b, ref Vector3 cp)
        {
            if (CrossCheck2D(a, b))
            {
                cp = CrossCheck2DVector(a, b);
                return true;
            }
            cp = Vector3.one * float.MaxValue;
            return false;
        }

        static Vector3 CrossCheck2DVector(Vector3[] p1, Vector3[] p2)
        {
            Vector3 a = p1[0];
            Vector3 b = p1[1];
            Vector3 c = p2[0];
            Vector3 d = p2[1];

            float Y = a.y;
            float x1, x2, x3, x4, z1, z2, z3, z4, X, Z;

            x1 = a.x; z1 = a.z;
            x2 = b.x; z2 = b.z;
            x3 = c.x; z3 = c.z;
            x4 = d.x; z4 = d.z;

            float cross = ((x1 - x2) * (z3 - z4) - (z1 - z2) * (x3 - x4));
            if (cross == 0 /* parallel */) return new Vector3(10000, 10000, 10000);

            X = ((x1 * z2 - z1 * x2) * (x3 - x4) - (x1 - x2) * (x3 * z4 - z3 * x4)) / cross;
            Z = ((x1 * z2 - z1 * x2) * (z3 - z4) - (z1 - z2) * (x3 * z4 - z3 * x4)) / cross;

            return new Vector3(X, Y, Z);
        }

        static bool CrossCheck2D(Vector3[] p1, Vector3[] p2)
        {
            Vector3 a = p1[0];
            Vector3 b = p1[1];
            Vector3 c = p2[0];
            Vector3 d = p2[1];

            // (x, Y , z)
            float Y = a.y;
            float x1, x2, x3, x4, z1, z2, z3, z4, X, Z;

            x1 = a.x; z1 = a.z;
            x2 = b.x; z2 = b.z;
            x3 = c.x; z3 = c.z;
            x4 = d.x; z4 = d.z;

            float cross = ((x1 - x2) * (z3 - z4) - (z1 - z2) * (x3 - x4));
            if (Mathf.Abs(cross) <0.05f /* parallel */)
            {
                return false;
            }

            X = ((x1 * z2 - z1 * x2) * (x3 - x4) - (x1 - x2) * (x3 * z4 - z3 * x4)) / cross;
            Z = ((x1 * z2 - z1 * x2) * (z3 - z4) - (z1 - z2) * (x3 * z4 - z3 * x4)) / cross;
            var distance = b - a;
            var legth = d - c;

            if (distance.normalized == legth.normalized)
                return false;

            return
                CheckDotInLine(a, b, new Vector3(X, Y, Z))
                && CheckDotInLine(c, d, new Vector3(X, Y, Z));
        }
        static bool CheckDotInLine(Vector3 a, Vector3 b, Vector3 dot)
        {
            float epsilon = 0.00001f;
            float dAB = Vector3.Distance(a, b);
            float dADot = Vector3.Distance(a, dot);
            float dBDot = Vector3.Distance(b, dot);

            return ((dAB + epsilon) >= (dADot + dBDot));
        }
    }
}