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

public class Move : MonoBehaviour
{
    private SnakeDirection _currentDirection = SnakeDirection.Up;
    public float Speed = 4f;
    public float CellSize = 5;

    public Transform SegmentPrefab;
    public GameObject FoodPrefab;
    public GameObject HeadPrefab;

    public List<Transform> StartBody = new List<Transform>();

    private List<Transform> _body = new List<Transform>();
    private Vector3 _startPos;


    void Start()
    {
        _startPos = transform.position;
        SpawnBody();
        StartCoroutine(MoveLogic());
        Food.SpawnFood(FoodPrefab);
    }

    void Update()
    {
        ReadDirection();
    }

    public IEnumerator MoveLogic()
    {
        while (true)
        {

            Vector3 previousPos = transform.position;
            switch (_currentDirection)
            {
                case SnakeDirection.Up:
                    transform.position += new Vector3(0, 0, -CellSize);
                    break;
                case SnakeDirection.Down:
                    transform.position += new Vector3(0, 0, CellSize);
                    break;
                case SnakeDirection.Left:
                    transform.position += new Vector3(CellSize, 0, 0);
                    break;
                case SnakeDirection.Right:
                    transform.position += new Vector3(-CellSize, 0, 0);
                    break;
            }
            foreach (var segment in _body) {
                Vector3 temp = segment.transform.position;
                segment.transform.position = previousPos;
                previousPos = temp;
            }
            yield return new WaitForSeconds(1 / Speed);
        }
    }

    public void ReadDirection()
    {
        if (Input.GetKeyDown(KeyCode.W) && _currentDirection != SnakeDirection.Down)
            _currentDirection = SnakeDirection.Up;
        else if (Input.GetKeyDown(KeyCode.S) && _currentDirection != SnakeDirection.Up)
            _currentDirection = SnakeDirection.Down;
        else if (Input.GetKeyDown(KeyCode.A) && _currentDirection != SnakeDirection.Right)
            _currentDirection = SnakeDirection.Left;
        else if (Input.GetKeyDown(KeyCode.D) && _currentDirection != SnakeDirection.Left)
            _currentDirection = SnakeDirection.Right;
    }

    public IEnumerator moveObject(GameObject obj, Vector3 destination)
    {
        float totalMovementTime = 5f; //the amount of time you want the movement to take
        float currentMovementTime = 2f;//The amount of time that has passed
        while (Vector3.Distance(obj.transform.localPosition, destination) > 0)
        {
            obj.transform.localPosition = Vector3.Lerp(obj.transform.position, destination, currentMovementTime / totalMovementTime);
            yield return null;
        }
    }

    private void OnCollisionEnter(Collision collision)
    {
        if (collision.gameObject.tag == "Body")
            print("Game Over!");
        else if (collision.gameObject.tag == "Food")
        {
            _body.Add(Instantiate(SegmentPrefab, _body[^1].position, Quaternion.identity));
            Destroy(collision.gameObject);
            Food.SpawnFood(FoodPrefab);
        }
        else if (collision.gameObject.tag == "Wall")
        {
            StopAllCoroutines();
            Death();
        }
    }

    private void SpawnBody()
    {
        Vector3 nextCellPos = new Vector3(_startPos.x + transform.localScale.x, _startPos.y, _startPos.z);
        StartBody.ForEach(body => {
            body.tag = "Body";
            _body.Add(Instantiate(body, nextCellPos, Quaternion.identity));
        });
    }

    private void Death()
    {
        _body.ForEach(x => Destroy(x.gameObject));
        _body.Clear();
        Destroy(gameObject);
        Instantiate(HeadPrefab, _startPos, Quaternion.identity);
    }
}