using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using MyTypes;
using Cinemachine;

public class Spawner : MonoBehaviour{

    static Spawner _instance;
    public static Spawner Instance{
        get{
            if (_instance == null){
                _instance = FindObjectOfType<Spawner>();

                if (_instance == null){
                    GameObject container = new GameObject("GameManager");
                    _instance = container.AddComponent<Spawner>();
                }
            }

            return _instance;
        }
    }

    [SerializeField] PlayerManager players;
    //[SerializeField] CinemachineVirtualCamera virtualCamera;

    public GameObject enemy;
    public GameObject spike;

    public GameObject SpawnPlayer(){
        PlayerManager playerManager = Instantiate(players);

        //playerManager.followCamera = virtualCamera;
        playerManager.Init();
        GameManager.Instance.Grid.grid[MyVars.p1StartPos.x, MyVars.p1StartPos.y].Pawn  = playerManager.Player1;
        GameManager.Instance.Grid.grid[MyVars.p2StartPos.x, MyVars.p2StartPos.y].Pawn = playerManager.Player2;

        GameManager.Instance.Grid.RemoveAvailableCell(playerManager.Player1.CurrentCell);
        GameManager.Instance.Grid.RemoveAvailableCell(playerManager.Player2.CurrentCell);

        return playerManager.gameObject;
    }

    public List<GameObject> SpawnEnemy(int amount)
    {
        List<MyCell> safetyCells = new List<MyCell>();
        if (GameManager.Instance.player != null)
        {
            

            for(int i=-1; i<2; i++)
            {
                for(int j=-1; j<2; j++)
                {
                    if (!(i == 0 && j == 0)) //prevent self cell check (player is there)
                    {
                        MyCell aux = GameManager.Instance.Grid.getCell(GameManager.Instance.player.GetComponent<PlayerManager>().Player1.CurrentCell.position, new Vector2Int(i, j));
                        if (aux.Pawn == null)
                        {
                            safetyCells.Add(aux);
                            GameManager.Instance.Grid.RemoveAvailableCell(aux);
                        }
                    }
                }
            } //check surrounding player1 cells
            for (int i = -1; i < 2; i++)
            {
                for (int j = -1; j < 2; j++)
                {
                    if (!(i == 0 && j == 0)) //prevent self cell check (player is there)
                    {
                        MyCell aux = GameManager.Instance.Grid.getCell(GameManager.Instance.player.GetComponent<PlayerManager>().Player2.CurrentCell.position, new Vector2Int(i, j));
                        if (aux.Pawn == null)
                        {
                            safetyCells.Add(aux);
                            GameManager.Instance.Grid.RemoveAvailableCell(aux);
                        }
                    }
                }
            } //check surrounding player2 cells

            //Safety cells have been removed from the available cells list. At the end of the methods, these cells will be fed back into the available cell list.
        }



        List<GameObject> enemies = new List<GameObject>();

        List<MyCell> cellsToAddBack = new List<MyCell>();
        for (int i = 0; i < amount; ++i)
        {
            GameObject auxEnemy = Instantiate(enemy, Vector3.zero, Quaternion.identity);
            enemies.Add(auxEnemy);
            MyCell auxCell = GameManager.Instance.Grid.GetAvailableCell();

            auxEnemy.transform.position = new Vector3 (auxCell.position.x*MyVars.cellSize, 0, auxCell.position.y * MyVars.cellSize);
            cellsToAddBack.Add(auxCell);
        }

        //pushing cells where the enemies spawned back into the available cell list since the enemies movement isnt grid-based and said cells should be occupiable by the player later on.
        for(int i=0; i<amount; ++i)
        {
            GameManager.Instance.Grid.AddAvailableCell(cellsToAddBack[cellsToAddBack.Count - 1]);
            cellsToAddBack.RemoveAt(cellsToAddBack.Count-1);
        }


        //feeding back the safety cells into the available cells list
        foreach(MyCell c in safetyCells)
        {
            GameManager.Instance.Grid.AddAvailableCell(c);
        }

        return enemies;
    }


    public List<GameObject> SpawnEnemy(int amount, float speed)
    {
        List<GameObject> enemies = new List<GameObject>();

        List<MyCell> cellsToAddBack = new List<MyCell>();
        for (int i = 0; i < amount; ++i)
        {
            GameObject auxEnemy = Instantiate(enemy, Vector3.zero, Quaternion.identity);
            auxEnemy.GetComponent<EnemyBehavior>().speed = speed;
            enemies.Add(auxEnemy);
            MyCell auxCell = GameManager.Instance.Grid.GetAvailableCell();

            auxEnemy.transform.position = new Vector3(auxCell.position.x * MyVars.cellSize, 0, auxCell.position.y * MyVars.cellSize);
            cellsToAddBack.Add(auxCell);
        }

        //pushing cells where the enemies spawned back into the available cell list since the enemies movement isnt grid-based and said cells should be occupiable by the player later on.
        for (int i = 0; i < amount; ++i)
        {
            GameManager.Instance.Grid.AddAvailableCell(cellsToAddBack[cellsToAddBack.Count - 1]);
            cellsToAddBack.RemoveAt(cellsToAddBack.Count - 1);
        }

        return enemies;
    }

    public List<GameObject> SpawnSpike(int amount)
    {
        List<GameObject> ans = new List<GameObject>();
        for (int i = 0; i < amount; ++i)
        {
            MyPawn auxSpike = Instantiate(spike, Vector3.zero, Quaternion.identity).GetComponent<SpikeBehavior>();
            GameManager.Instance.Grid.GetAvailableCell().Pawn = auxSpike;
            ans.Add(auxSpike.gameObject);
        }

        return ans;
    }

}