using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEngine;

namespace TheraBytes.BetterUi
{
    public static class RectTransformExtensions
    {

        public static Rect ToScreenRect(this RectTransform self, bool startAtBottom = false, Canvas canvas = null,
            bool localTransform = false)
        {
            Vector3[] corners = new Vector3[4];
            Vector3[] screenCorners = new Vector3[2];

            if (localTransform)
            {
                self.GetLocalCorners(corners);
            }
            else
            {
                self.GetWorldCorners(corners);
            }

            int idx1 = (startAtBottom) ? 0 : 1;
            int idx2 = (startAtBottom) ? 2 : 3;


            if (canvas != null && (canvas.renderMode == RenderMode.ScreenSpaceCamera || canvas.renderMode == RenderMode.WorldSpace))
            {
                screenCorners[0] = RectTransformUtility.WorldToScreenPoint(canvas.worldCamera, corners[idx1]);
                screenCorners[1] = RectTransformUtility.WorldToScreenPoint(canvas.worldCamera, corners[idx2]);
            }
            else
            {
                screenCorners[0] = RectTransformUtility.WorldToScreenPoint(null, corners[idx1]);
                screenCorners[1] = RectTransformUtility.WorldToScreenPoint(null, corners[idx2]);
            }

            if (!(startAtBottom))
            {
                screenCorners[0].y = Screen.height - screenCorners[0].y;
                screenCorners[1].y = Screen.height - screenCorners[1].y;
            }

            return new Rect(screenCorners[0], screenCorners[1] - screenCorners[0]);
        }

    }
}