using System;
using System.Collections.Generic;
using System.Linq;
using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.Rendering.Universal;
using static UnityEngine.Mathf;

public class CameraOperator : MonoBehaviour
{
	private Dictionary<int, GameObject> players = new Dictionary<int, GameObject>();

	[SerializeField]
	private int MaxAdditionalDistance = 15;


	private float InitialDistance = 0;
	private float MaxDistance;

	private Camera cam;

	private void Awake()
	{
		cam = gameObject.GetComponent<Camera>();
		// Distance here is in the negative direction on the z axis
		InitialDistance = transform.localPosition.z;
		MaxDistance = InitialDistance - MaxAdditionalDistance;
	}

	public void AddPlayer(GameObject player)
	{
		players[player.GetInstanceID()] = player;
	}

	public void RemovePlayer(int id)
	{
		players.Remove(id);
	}

	/// <summary>
	/// Rotates the camera to point at the center between the players.
	/// </summary>
	private void LateUpdate()
	{
		CenterBetweenPlayers();
		AdjustZoom();
	}

	private void CenterBetweenPlayers()
	{
		if (players.Count < 1)
		{
			return;
		}
		float x = transform.localPosition.x;
		float y = transform.localPosition.y;
		float z = transform.localPosition.z;
		foreach (GameObject p in players.Values)
		{
			if (p.IsDestroyed())
				continue;
			Vector3 position = p.transform.localPosition;
			z = position.z;
			x += position.x;
			y += position.y;
		}
		x /= players.Count();
		y /= players.Count();
		float a = z - InitialDistance;
		float cXAxis = (float)Sqrt(Pow(a, 2) + Pow(x, 2));
		float cYAxis = (float)Sqrt(Pow(a, 2) + Pow(y, 2));
		Vector3 xyRotation = new Vector3(Rad2Deg * Acos(a / cYAxis) * -Math.Sign(y),
										 Rad2Deg * Acos(a / cXAxis) * Math.Sign(x), 0);
		if (transform.localEulerAngles != xyRotation / 2)
		{
			transform.localEulerAngles = xyRotation / 2;
		}
	}
	private void AdjustZoom()
	{
		if (players.Count < 2)
		{
			return;
		}
		float Margin = Screen.height / 2;

		float maxXDistance = 0;
		float maxYDistance = 0;

		foreach (GameObject player in players.Values)
		{
			var screenPos1 = cam.WorldToScreenPoint(player.transform.position);
			foreach (GameObject p in players.Values)
			{
				if (p == player)
					continue;
				var screenPos2 = cam.WorldToScreenPoint(p.transform.position);
				var distance = screenPos2 - screenPos1;
				float xDistance = Abs(distance.x);
				if (maxXDistance < xDistance)
					maxXDistance = xDistance;
				float yDistance = Abs(distance.y);
				if (maxYDistance < yDistance)
					maxYDistance = Abs(distance.y);
			}
		}
		if (maxXDistance < Screen.width - Margin
		&& maxYDistance < Screen.height - Margin)
		{
			if (transform.localPosition.z < InitialDistance + 0.1f)
				transform.localPosition += new Vector3(0, 0, 0.1f);
			return;
		}

		if (transform.localPosition.z > MaxDistance - 0.1f)
			transform.localPosition -= new Vector3(0, 0, 0.1f);

	}
}