using Network;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using UnityEngine;
using UnityEngine.Networking;

namespace ResourceLoading
{
    public class HttpImageDownloader : ImageDownloader
    {
        private UnityWebRequest request = null;
        private DownloadHandlerTexture downloadHandler = null;

        private class ConsoleCertificateHandler : CertificateHandler
        {
            private X509Certificate2 certificate;

            public ConsoleCertificateHandler(ConsoleServer resourceServer)
            {
                certificate = ImportCertFromBase64(resourceServer.TlsCertificate);
            }

            protected override bool ValidateCertificate(byte[] certificateData)
            {
                X509Certificate2 certificateDataX509 = new X509Certificate2(certificateData);
                return certificateDataX509.GetPublicKeyString().ToLower().Equals(certificate.GetPublicKeyString().ToLower());
            }

            public X509Certificate2 ImportCertFromBase64(string certificate)
            {
                if (string.IsNullOrEmpty(certificate))
                    return new X509Certificate2();

                var certBytes = Encoding.UTF8.GetBytes(certificate);
                return new X509Certificate2( certBytes, "XXXXXXXXXXXXXX", X509KeyStorageFlags.Exportable);
            }
        }

        public HttpImageDownloader(string url, ConsoleServer resourceServer)
        {
            request = UnityWebRequestTexture.GetTexture(url);

            // apply certificate pinning for the console certificate, if the url contains the console address
            if (resourceServer != null)
            {
                var splittedUrl= resourceServer.PairingUrl.Split(new char[] { '/',':' }, System.StringSplitOptions.RemoveEmptyEntries);
                if(splittedUrl.Length>1)
                { 
                    if (url.Contains(splittedUrl[1]))
                    {
                        Debug.Log("Console Certificate handled ! ");
                        request.certificateHandler = new ConsoleCertificateHandler(resourceServer);
                    }
                }
            }

            request.SendWebRequest();

            downloadHandler = (DownloadHandlerTexture)request.downloadHandler;
        }

        public void Dispose()
        {
            request.Dispose();
            request = null;

            downloadHandler = null;
        }

        #region ImageDownloader interface

        public bool IsDone { get { return request.isDone; } }

        // texture created from the downloaded image
        public Texture2D Texture { get { return downloadHandler.texture; } }

        // result of the download process
        public string Error { get { return request.error; } }

        // raw access to downloaded data
        public byte[] Bytes { get { return downloadHandler.data; } }

        #endregion
    }
}