//
//  PostJson.cs
//
//  Author:
//       Paul Schneider <paulschneider@free.fr>
//
//  Copyright (c) 2015 Paul Schneider
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
using System.Net;
using System.IO;
using System.Json;
using System.Threading.Tasks;
using Newtonsoft.Json;
using System;
using System.Diagnostics;
using BookAStar;

namespace Yavsc.Helpers
{
    /// <summary>
    /// Simple json post method.
    /// </summary>
    public class SimpleJsonPostMethod : IDisposable
	{
    private HttpWebRequest request=null;

		/// <summary>
		/// Initializes a new instance of the Yavsc.Helpers.SimpleJsonPostMethod class.
		/// </summary>
		/// <param name="pathToMethod">Path to method.</param>
		public SimpleJsonPostMethod (string pathToMethod, string authorizationHeader = null)
		{
			request = (HttpWebRequest) WebRequest.Create ($"{BasePath}/{pathToMethod}");
			request.Method = "POST";
			request.Accept = "application/json";
			request.ContentType = "application/json";
			request.SendChunked = true;
			request.TransferEncoding = "UTF-8";
            if (authorizationHeader!=null) 
                request.Headers.Add($"Authorization: {authorizationHeader}");
        }

        public static string BasePath { get; private set; } = Constants.YavscApiUrl;

        public void Dispose()
        {
            request.Abort();
        }

        /// <summary>
        /// Invoke the specified query.
        /// </summary>
        /// <param name="query">Query.</param>
        public TAnswer Invoke<TAnswer>(object query)
		{

			using (Stream streamQuery = request.GetRequestStream()) {
				using (StreamWriter writer = new StreamWriter(streamQuery)) {
					writer.Write (JsonConvert.SerializeObject(query));
				}}
			TAnswer ans = default (TAnswer);
			using (WebResponse response = request.GetResponse ()) {
				using (Stream responseStream = response.GetResponseStream ()) {
					using (StreamReader rdr = new StreamReader (responseStream)) {
						ans = (TAnswer) JsonConvert.DeserializeObject<TAnswer> (rdr.ReadToEnd ());
					}
				}
				response.Close();
			}
			return ans;
		}

		public async Task<JsonValue> InvokeJson(object query)
        {
            JsonValue jsonDoc = null;

            try
            {
                using (Stream streamQuery = request.GetRequestStream())
                {
                    using (StreamWriter writer = new StreamWriter(streamQuery))
                    {
                        writer.Write(JsonConvert.SerializeObject(query));
                    }
                }
                using (WebResponse response = request.GetResponse())
                {
                    using (Stream stream = response.GetResponseStream())
                    {
                        if (stream.Length > 0)
                            jsonDoc = await Task.Run(() => JsonObject.Load(stream));
                    }
                    response.Close();
                }
            }
            catch (WebException ex)
            {
                // TODO err logging
                Debug.Print($"Web request failed: {request.ToString()}\n" + ex.ToString());
            }
            catch (Exception ex)
            {
                Debug.Print($"Web request failed: {request.ToString()}\n" + ex.ToString());
            }

            return jsonDoc;
		}
	}
}