using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using ZXing;
using ZXing.QrCode;

public class QRCode : MonoBehaviour {
    public string QRCodeString;
    [SerializeField]
    private Texture2D QRResult;
    const int QRSize = 256;
    private Vector2 width_height = new Vector2(QRSize, QRSize);

    [Serializable]
    public class QRResultEvent : UnityEvent<Texture> { };
    [SerializeField]
    public QRResultEvent qrcodeEvent = new QRResultEvent();

    List<Texture> results = new List<Texture>();

    private void Update()
    {
        lock (results)
        {
            foreach (var r in results)
            {
                if (qrcodeEvent != null)
                {
                    qrcodeEvent.Invoke(r);
                }
            }
            results.Clear();
        }
    }

    public void Encode()
    {
        Color32[] color32 = useEncode(QRCodeString, (int)width_height.x, (int)width_height.y);

        if(QRResult == null)
            QRResult = new Texture2D((int)width_height.x, (int)width_height.y);

        QRResult.SetPixels32(color32);
        QRResult.Apply();
        if(qrcodeEvent != null)
            qrcodeEvent.Invoke(QRResult);
    }

    private Color32[] useEncode(string textForEncoding, int width, int height)
    {
        Debug.Log("Encode QR code: " + textForEncoding);
        BarcodeWriter writer = new BarcodeWriter
        {
            Format = BarcodeFormat.QR_CODE,
            Options = new QrCodeEncodingOptions
            {
                Height = height,
                Width = width
            }
        };
        return writer.Write(textForEncoding);
    }
}