using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace nuget_cli
{
    public class UploadFilesToServerUsingWebRequest
    {

        /// <summary>
        /// Creates HTTP POST request & uploads database to server. Author : Farhan Ghumra
        /// </summary>
        internal async Task UploadFilesToServerAsync(PushReport report, Uri uri, FileInfo fi,
       string apikey)
        {

            // string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
            const int TXLEN = 0x1000;
            /// the form-data file upload, properly formatted
            string fileheaderTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\";\r\nContent-Type: {2}\r\n\r\n";

            ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };

            // "X-NuGet-ApiKey
            string boundary = "----------" + DateTime.Now.Ticks.ToString("x");
            byte[] boudaryByte = Encoding.ASCII.GetBytes(boundary);
            byte[] trailer = Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
            string fileheader = string.Format(fileheaderTemplate, "file", fi.Name, "application/octet-stream");
            byte[] fileheaderbytes = Encoding.ASCII.GetBytes(fileheader);

            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(uri);

            httpWebRequest.Method = "PUT";
            httpWebRequest.ContentType = "multipart/form-data; boundary=" + boundary;
            httpWebRequest.AllowAutoRedirect = false;
            httpWebRequest.Headers.Add("X-NuGet-Client-Version", Constants.ClientVersion);
            httpWebRequest.Headers.Add("X-NuGet-ApiKey", apikey);
            httpWebRequest.ContentLength = boudaryByte.Length + fileheaderbytes.Length + fi.Length + trailer.Length;


            httpWebRequest.BeginGetRequestStream((result) =>
            {
                try
                {
                    HttpWebRequest request = (HttpWebRequest)result.AsyncState;

                    using (Stream requestStream = request.EndGetRequestStream(result))
                    {
                        WriteToStream(requestStream, boudaryByte, boudaryByte.Length);
                        WriteToStream(requestStream, fileheaderbytes, fileheaderbytes.Length);
                        // WriteToStream(s, string.Format(fileheaderlentemplate, fi.Length));
                        /// Write the file data to the stream.
                        using (var fss = fi.OpenRead())
                        {
                            byte[] buffer = new byte[TXLEN];
                            var form_bytes_read = fss.Read(buffer, 0, TXLEN);
                            while (form_bytes_read > 0)
                            {
                                WriteToStream(requestStream, buffer, form_bytes_read);
                                form_bytes_read = fss.Read(buffer, 0, TXLEN);
                            }
                        }
                        requestStream.Write(trailer, 0, trailer.Length);
                        //requestStream.Close();
                    }
                    request.BeginGetResponse(a =>
                    {
                        try
                        {
                            var response = request.EndGetResponse(a);
                            var responseStream = response.GetResponseStream();
                            using (var sr = new StreamReader(responseStream))
                            {
                                using (StreamReader streamReader = new StreamReader(response.GetResponseStream()))
                                {
                                    string responseString = streamReader.ReadToEnd();
                                    //responseString is depend upon your web service.
                                    if (responseString == "Success")
                                    {
                                        report.Message = "stored successfully on server.";
                                    }
                                    else
                                    {
                                        report.Message = "Error occurred while uploading packet on server.";
                                    }
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            report.Message = ex.Message;
                            Console.Error.WriteLine(ex.Message);
#if DEBUG
                            Console.Error.WriteLine("Stack trace:");
                            Console.Error.WriteLine(ex.StackTrace);
#endif
                        }
                    }, null);
                }
                catch (Exception rex)
                {
                    report.Message = rex.Message;
                    Console.Error.WriteLine(rex.Message);
#if DEBUG
                    Console.Error.WriteLine("Stack trace:");
                    Console.Error.WriteLine(rex.StackTrace);
#endif
                }
            }, httpWebRequest);

            WebResponse resp = httpWebRequest.GetResponse();
            Stream stream = resp.GetResponseStream();
            StreamReader re = new StreamReader(stream);
            String json = re.ReadToEnd();
            report.Message = json;
        }

        /// <summary>
        /// Writes string to stream. Author : Farhan Ghumra
        /// </summary>
        private static void WriteToStream(Stream s, string txt)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(txt);
            s.Write(bytes, 0, bytes.Length);
        }

        /// <summary>
        /// Writes byte array to stream. Author : Farhan Ghumra
        /// </summary>
        private static void WriteToStream(Stream s, byte[] bytes, int len)
        {
            s.Write(bytes, 0, len);
        }
    }
}