using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

public class RuntimeTransformGizmo : RuntimeGizmo
{
    protected Material redMaterial;
    protected Material greenMaterial;
    protected Material blueMaterial;
    protected Material yellowMaterial;
    protected Material whiteMaterial;

    //the vector projected by Gizmo XYZ axis on the screen
    protected Vector2 gizmoXYZScreenStart;
    protected Vector2 gizmoXYZScreenDirection;

    protected enum Axis { X, Y, Z }


    public override void Initialize()
    {
        //Material Initialize
        yellowMaterial = Resources.Load<Material>("Materials/Yellow");
        whiteMaterial = Resources.Load<Material>("Materials/White");
    }
    public override void Update() { }

    protected override void RenderUpdate() 
    {
        base.RenderUpdate();
    }

    protected override void FollowUpdate() { }

    public override void EnableGizmo(GameObject target)
    {
        base.EnableGizmo(target);
    }

    public override void DisableGizmo()
    {
        base.DisableGizmo();
    }
    public override void OnSelect(string handleName) { }

    public override void OnUnSelect() { }
    protected override void OnSelecting() { }

    protected override void ChangeRenderOnSelect() { }
    protected override void ChangeRenderOnUnSelect() { }


    protected Vector3? GetIntersectionPlaneAndLine(Axis axis, Vector3 lineStart, Vector3 lineDirection)
    {
        Vector4 plane = GetPlane(axis);
        Vector3 planeNormal = new Vector3(plane.x, plane.y, plane.z);
        Vector3? intersectionPoint = GetIntersectionPlaneAndLine(planeNormal, plane.w, lineStart, lineDirection);
        return intersectionPoint;
    }

    protected Vector3? GetIntersectionPlaneAndLine(Vector3 planeNormal, float d, Vector3 lineStart, Vector3 lineDirection)
    {
        // Plane: Ax + By + Cz + D = 0
        // Line: P(t) = P0 + tD

        float a = planeNormal.x;
        float b = planeNormal.y;
        float c = planeNormal.z;

        float dx = lineDirection.x;
        float dy = lineDirection.y;
        float dz = lineDirection.z;

        float denominator = a * dx + b * dy + c * dz;

        if (Math.Abs(denominator) < 0.0001f) return null;

        float t = -(a * lineStart.x + b * lineStart.y + c * lineStart.z + d) / denominator;

        Vector3 intersectionPoint = lineStart + t * lineDirection;
        return intersectionPoint;
    }

    protected Vector4 GetPlane(Axis axis)
    {
        Vector4 plane = new Vector4();
        Vector3 normal = new Vector3();
        switch (axis)
        {
            case Axis.X:
                normal = gizmo.GetComponent<Transform>().right;
                break;
            case Axis.Y:
                normal = gizmo.GetComponent<Transform>().up;
                break;
            case Axis.Z:
                normal = gizmo.GetComponent<Transform>().forward;
                break;
        }
        plane.x = normal.x;
        plane.y = normal.y;
        plane.z = normal.z;
        Vector3 position = gizmo.GetComponent<Transform>().position; 
        plane.w = -Vector3.Dot(position,normal);
        return plane;
    }
}