using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Serialization;
using UnityEngine.UI;

//[ExecuteInEditMode]
public class ShaderFade : MonoBehaviour
{
    public string shader = "2DxFX_Extra_Shaders/AlphaIntensity";
    public string nameValue = "_AlphaIntensity_Fade_1";

    public string nameOn = string.Empty;
    public List<ShaderValue> values_Init;

    [Space(10)]
    public bool isPlay = false;
    public bool LOOP = false;
    [Space(10)]
    [Range(0, 5)]
    public float duration = 3f;
    public AnimationCurve curve;
    [Range(0, 100)]
    public float valueMax = 6;

    float durationSum = 0;
    float timeCurve;

    Image CanvasImage;

    [Space(10)]
    public Material material;
    public List<Image> listShared;

    private void Start()
    {
        Init();
    }
    void Init()
    {
        if (CanvasImage == null)
        {
            CanvasImage = this.gameObject.GetComponent<Image>();
            if (material == null)
            {
                material = new Material(Shader.Find($"{shader}"));

                if (material != null)
                {
                    if (nameOn != string.Empty)
                        material.EnableKeyword(nameOn);

                    for(int i = 0; i < values_Init.Count; i++)
                        material.SetFloat($"{values_Init[i].name}", values_Init[i].value);
                }
            }
        }
    }
    void Update()
    {
        if (isPlay && material != null)
        {
            durationSum += Time.deltaTime;
            timeCurve = durationSum / duration;

            if (CanvasImage.material != material)
                MaterialApply(material);

            material.SetFloat($"{nameValue}", valueMax * curve.Evaluate(timeCurve));

            if (isPlay && duration < durationSum)
            {
                durationSum = 0;

                if (!LOOP)
                {
                    if (OnEnd != null)
                        OnEnd();

                    if (KEEP)
                    {
                        isPlay = false;
                        enabled = isPlay;
                    }
                    else
                    {
                        Play(false, false, null);

                        OnEndPlay();
                    }
                }
            }
        }
    }

    System.Action OnEnd;
    bool KEEP = false;
    public void Play(bool isPlay, bool LOOP, System.Action OnEnd, bool KEEP = false)
    {
        Init();

        MaterialApply(isPlay ? material : null);

        this.isPlay = isPlay;
        this.LOOP = LOOP;
        this.OnEnd = OnEnd;
        this.KEEP = KEEP;

        enabled = isPlay;
    }
    public void Play()
    {
        Init();

        MaterialApply(isPlay ? material : null);

        isPlay = true;

        enabled = isPlay;
    }
    void MaterialApply(Material material)
    {
        CanvasImage.material = material;

        for (int i = 0; i < listShared.Count; i++)
            listShared[i].material = material;
    }
    public void ValueSet(float value)
    {
        Init();

        MaterialApply(material);
        if (material != null)
            material.SetFloat($"{nameValue}", value);

        gameObject.SetActive(true);
    }
    public void ValueSet(string nameValue, float value)
    {
        Init();

        MaterialApply(material);
        if (material != null)
            material.SetFloat($"{nameValue}", value);

        gameObject.SetActive(true);
    }

    [Serializable]
    public class EndEvent : UnityEvent { }
    [FormerlySerializedAs("onEnd")]
    [SerializeField]
    private EndEvent m_OnEnd = new EndEvent();
    public EndEvent OnPlayEnd
    {
        get { return m_OnEnd; }
        set { m_OnEnd = value; }
    }
    public void OnEndPlay()
    {
        OnPlayEnd.Invoke();
    }
}