using System.Linq;
using System.Collections;
using System.Threading.Tasks;
using System.Collections.Generic;

using DG.Tweening;
using UnityEngine;

public class Train : MonoBehaviour
{
    public TrainType type;
    public bool useEffect;
    private LocomotionHandler locomotionHandler;
    private Coroutine c_effect;
    private List<Material> materials = new();
    private float effectDuration = .4f;

    void OnEnable()
    {
        var uiMenu = FindObjectOfType<UIMainMenu>();
        uiMenu.currentTrain = this;

        if(materials.Count == 0)
        {
            materials = GetComponent<MeshRenderer>().materials.ToList();
            var materialsInChildren = gameObject.transform
                .GetChild(0)
                .GetComponent<MeshRenderer>()
                .materials.ToList();

            foreach(var mat in materialsInChildren)
                materials.Add(mat);
        }

        if(!useEffect)
        {
            SetEffect(true);

            if(locomotionHandler == null)
                locomotionHandler = FindObjectOfType<LocomotionHandler>();

            var startPosition = locomotionHandler.pullUpPositionBefore;
            var speed = locomotionHandler.trainSpeed;

            transform.localPosition = new Vector3(transform.localPosition.x,
                transform.localPosition.y,
                startPosition);

            transform.DOLocalMoveZ(-16, speed)
                .SetEase(Ease.OutSine);
        }
        else SetEffect(true);
    }

    public async void Hide()
    {
        if(!useEffect)
        {
            var endPosition = locomotionHandler.pullUpPositionAfter;
            var speed = locomotionHandler.trainSpeed;

            transform.DOLocalMoveZ(endPosition, speed)
                .SetEase(Ease.InSine)
                .OnComplete(() => gameObject.SetActive(false));

            await Task.Delay(3000); 
            SetEffect(false);
        }
        else SetEffect(false);
    }

   void SetEffect(bool isShow)
    {
        if(c_effect != null)
        {
            StopCoroutine(c_effect);
            c_effect = null;
        }

        c_effect = StartCoroutine(SetEffectRoutine(isShow));
    }

    IEnumerator SetEffectRoutine(bool isShow)
    {
        float startPosition = isShow ? -5 : 3;
        float currentValue = startPosition;
        float endPosition = 0;

        if(isShow) endPosition = 3;
        else endPosition = -5;

        float progress = 0;
        float duration = effectDuration;

        while(progress < 1)
        {
            currentValue = Mathf.Lerp(startPosition, endPosition, progress);

            for(int i = 0; i < materials.Count; i++)
            {
                materials[i]
                    .SetFloat("_EffectPosition", currentValue);
            }

            progress += duration * Time.deltaTime;
            yield return null;
        }

        for(int i = 0; i < materials.Count; i++)
        {
            materials[i]
                .SetFloat("_EffectPosition", endPosition);
        }

        if(!isShow && useEffect)
            gameObject.SetActive(false);
    }
}