using System;
using UnityEngine;
using UnityEngine.Serialization;

namespace EnergyBarToolkit
{
	[ExecuteInEditMode]
	public class EnergyBarFollowObject : MonoBehaviour
	{
		public GameObject followObject;

		public Vector3 offset;

		[FormerlySerializedAs("barRotation")]
		public Vector3 rotation;

		public ObjectFinder worldCamera = new ObjectFinder(typeof(Camera), "/Main Camera", "MainCamera", ObjectFinder.Method.ByTag);

		public bool lookAtCamera = true;

		public bool updateLookupReference;

		[SerializeField]
		[HideInInspector]
		private Camera renderCamera;

		private Camera cameraReference;

		private Canvas canvas;

		public bool IsPossiblyVisible()
		{
			if (followObject != null && cameraReference != null)
			{
				Vector3 lhs = followObject.transform.position - cameraReference.transform.position;
				float num = Vector3.Dot(lhs, cameraReference.transform.forward);
				return num >= 0f;
			}
			Debug.LogError("Cannot determine visibility of this bar.", this);
			return false;
		}

		private void OnEnable()
		{
		}

		private void Start()
		{
		}

		private void Update()
		{
			if (!(followObject != null))
			{
				return;
			}
			if (!Application.isPlaying || canvas == null)
			{
				canvas = GetComponentInParent<Canvas>();
				if (canvas == null)
				{
					Debug.LogError("This object should be placed under a canvas", this);
				}
			}
			if (!Application.isPlaying || cameraReference == null || updateLookupReference)
			{
				cameraReference = worldCamera.Lookup<Camera>(this);
			}
			UpdateFollowObject();
			bool flag = IsPossiblyVisible();
			EnergyBarBase component = GetComponent<EnergyBarBase>();
			component.opacity = (flag ? 1 : 0);
			if (cameraReference != null && canvas != null)
			{
				if (canvas.renderMode == RenderMode.WorldSpace && lookAtCamera)
				{
					component.transform.rotation = Quaternion.LookRotation(component.transform.position - cameraReference.transform.position);
				}
				else
				{
					component.transform.rotation = Quaternion.Euler(rotation);
				}
			}
		}

		private void UpdateFollowObject()
		{
			switch (canvas.renderMode)
			{
			case RenderMode.ScreenSpaceOverlay:
				UpdateFollowObjectScreenSpaceOverlay();
				break;
			case RenderMode.ScreenSpaceCamera:
				UpdateFollowObjectScreenSpaceCamera();
				break;
			case RenderMode.WorldSpace:
				UpdateFollowObjectWorldSpace();
				break;
			default:
				throw new ArgumentOutOfRangeException();
			}
		}

		private void UpdateFollowObjectScreenSpaceOverlay()
		{
			UpdateScreenSpace();
		}

		private void UpdateFollowObjectScreenSpaceCamera()
		{
			UpdateScreenSpace();
		}

		private void UpdateScreenSpace()
		{
			if (cameraReference == null)
			{
				Debug.LogError("Render Camera must be set for the follow script to work.", this);
				return;
			}
			Rect pixelRect = canvas.pixelRect;
			float x = pixelRect.width / 2f;
			float y = pixelRect.height / 2f;
			Vector3 vector = cameraReference.WorldToScreenPoint(followObject.transform.position);
			Vector3 vector2 = vector + offset - new Vector3(x, y);
			MadTransform.SetLocalPosition(localPosition: new Vector3(vector2.x / canvas.scaleFactor, vector2.y / canvas.scaleFactor), transform: base.transform);
		}

		private void UpdateFollowObjectWorldSpace()
		{
			MadTransform.SetPosition(base.transform, followObject.transform.position + offset);
		}
	}
}