using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using Cinemachine;
using UnityEngine.Playables;

public class Dissolve : MonoBehaviour
{

    public float Duration = 1;
    public float Delay = 0;
    public bool DissolveOnAwake = false;

    private float StartValue = 0;
    private float EndValue = 1;
    private bool StartSolve = false;
    
    private float TimeCross = 0;
    private const string _mainTextureName = "_MainTex";
    private const string _bumpTextureName = "_BumpTex";
    private const string _channelTextureName = "_ChannelTex";

    private List<Material> _NewMaterials = new List<Material>();

    private void OnEnable()
    {
        if (DissolveOnAwake)
            StartDissolove();
    }

    public void StartDissolove()
    {
        if (_NewMaterials.Count <= 0)
        {
            var DissolveMat = CommonUtility.LoadSharedMaterial("Dissolve");

            Renderer[] renders = GetComponentsInChildren<Renderer>();
            for (int i = 0; i < renders.Length; i++)
            {
                var material = Object.Instantiate(DissolveMat);
                if (material == null)
                    continue;
                _NewMaterials.Add(material);
                ReplaceTexture(renders[i].sharedMaterial, material, _mainTextureName);
                ReplaceTexture(renders[i].sharedMaterial, material, _bumpTextureName);
                ReplaceTexture(renders[i].sharedMaterial, material, _channelTextureName);
                renders[i].sharedMaterial = material;
            }
        }

        for (int i = 0; i < _NewMaterials.Count; i++)
        {
            var material = _NewMaterials[i];
            material.SetFloat("_DissolveEnd", StartValue);
        }

        TimeCross = Delay < 0 ? 0 : Delay;
        StartSolve = false;
    }

    public void ReplaceTexture(Material source, Material target, string textureName)
    {
        var result = source.HasProperty(textureName) && target.HasProperty(textureName);
        if (result)
        {
            var texture = source.GetTexture(textureName);
            var offset = source.GetTextureOffset(textureName);
            var scale = source.GetTextureScale(textureName);
            target.SetTexture(textureName, texture);
            target.SetTextureOffset(textureName, offset);
            target.SetTextureScale(textureName, scale);
        }
    }

    private void OnDestroy()
    {
        for(int i=0;i< _NewMaterials.Count;i++)
        {
            Object.Destroy(_NewMaterials[i]);
        }
        _NewMaterials.Clear();
    }

    void Update()
    {
        if(TimeCross > 0 && StartSolve == false)
        {
            TimeCross -= Time.deltaTime;
            return;
        }
        if(StartSolve == false)
        {
            StartSolve = true;
            TimeCross = 0;
        }
        if (TimeCross < 0)
            return;
        float value = Mathf.Lerp(StartValue, EndValue, TimeCross / Duration);
        if (TimeCross > Duration)
            TimeCross = -1;
        else
            TimeCross += Time.deltaTime;
        for(int i=0;i< _NewMaterials.Count;i++)
        {
            var material = _NewMaterials[i];
            material.SetFloat("_DissolveEnd", value);
        }
    }

}