using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
using UnityEngine.Networking;

public class PhotoTransition : MonoBehaviour
{
    public List<string> imgPathList = null;

    [SerializeField]
    List<Texture2D> _imgList = new List<Texture2D>();

    private Panorama180View.Panorama180View _panorama180View = null;
    private int _state = 0;

    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
      
    }

    IEnumerator BlendImage(Texture2D srcImg, Texture2D destImg)
    {
        _panorama180View.SetSrcTexture(srcImg);
        _panorama180View.SetDestTexture(destImg);

        _panorama180View.SetTransitionInterval(2.0f);
        _panorama180View.SetStateTransition(Panorama180View.Panorama180View.StateTransitionType.Blend);

        yield return new WaitForSeconds(2);
    }

    public IEnumerator LoadNextImage()
    {
        if (_state < imgPathList.Count - 1)
        {
            yield return StartCoroutine(BlendImage(_imgList[_state], _imgList[_state + 1]));
            _state++;
        }

        if (_imgList.Count < imgPathList.Count)
        {
            yield return StartCoroutine(ImageLoader(imgPathList[_state + 1]));
        }
    }

    public bool IsSlideshowFinished()
    {
        if (_state == imgPathList.Count-1) return true;
        return false;
    }

    public void Reset()
    {
        _imgList.Clear();
        _state = 0;
    }

    public IEnumerator SetUp()
    {
        // Load first two images
        for (int i = 0; i < 2; i++)
        {
            yield return StartCoroutine(ImageLoader(imgPathList[i]));
        }

        _panorama180View = this.GetComponent<Panorama180View.Panorama180View>();
        _panorama180View.SetSrcTexture(_imgList[0]);

        _panorama180View.SetTransitionInterval(2.0f);

        _panorama180View.SetStateTransition(Panorama180View.Panorama180View.StateTransitionType.FadeIn);
    }

    IEnumerator ImageLoader(string path)
    {
        string imgPath = Path.Combine(Application.streamingAssetsPath, path);
        // imgPath = "file://" + imgPath;  // For testing in editor

        using (UnityWebRequest uwr = UnityWebRequestTexture.GetTexture(imgPath))
        {
            yield return uwr.SendWebRequest();

            if (uwr.result != UnityWebRequest.Result.Success)
            {
                Debug.Log(uwr.error);
            }
            else
            {
                Texture2D tex = DownloadHandlerTexture.GetContent(uwr);
                _imgList.Add(tex);
            }
        }
    }
}