using Newtonsoft.Json;
using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;

namespace Neo.Afx.WinService.Messages
{
    /// <summary>
    /// A wrapper class for sending SMS's using the Vodacom API.
    /// </summary>
    public class SmsVodacom : ISmsSender
    {
        private string UserReference { get; set; }
        private string UserName { get; set; }
        private string Password { get; set; }
        private string AuthorizationHeader { get; set; }

        private class MessageObject
        {
            [JsonProperty("to")]
            public string To { get; set; }

            [JsonProperty("message")]
            public string Message { get; set; }

            [JsonProperty("ems")]
            public string Ems { get; set; }

            [JsonProperty("userref")]
            public string Userref { get; set; }

        }

        private class MessageResponse
        {
            public HttpStatusCode HttpStatusCode { get; set; }
            public string Message { get; set; }

        }

        public int Credits
        {
            get
            {
                return 100000;
            }
        }

        #region Initialization

        /// <summary>
        /// Initializes a new instance of the <see cref="Vodacom"/> class
        /// by using the given values.
        /// </summary>
        /// <param name="apiID">The API ID to be queried.</param>
        /// <param name="userName">The user name to be queried.</param>
        /// <param name="password">The password to be queried.</param>
        public SmsVodacom(string userReference, string userName, string password)
        {
            try
            {
                this.UserReference = userReference;
                this.UserName = userName;
                this.Password = password;

                this.AuthorizationHeader = this.EncodeAuthorizationHeader();
            }
            catch (Exception ex)
            {
                throw new Exception(GetInnermostMessage(ex));
            }
        }

        #endregion

        #region Send

        /// <summary>
        /// Sends the given message to the given cell number.
        /// </summary>
        /// <param name="message">The message to be sent.</param>
        /// <param name="cellNumber">The cell number to which the message is sent.</param>
        /// <param name="error">When this method returns, contains the error message if
        /// the SMS was not sent successfully; otherwise contains a null references.</param>
        /// <returns>
        /// 	<code>true</code> if successful; <code>false</code> otherwise.
        /// </returns>
        public bool Send(string message, string cellNumber, out string error)
        {
            bool successful;
            try
            {
                cellNumber = cellNumber.Substring(0, 1) != "+" ? string.Concat("+", cellNumber) : cellNumber;

                var response = SendMsg(new MessageObject() { Message = message, To = cellNumber, Ems = "1", Userref = this.UserReference });

                error = response.Message;

                if (response.HttpStatusCode != HttpStatusCode.OK)
                    successful = false;
                else
                    successful = true;
            }
            catch (Exception ex)
            {
                error = GetInnermostMessage(ex);
                successful = false;
            }
            return successful;
        }

        #endregion

        #region GetInnermostMessage
        public string GetInnermostMessage(Exception ex)
        {
            if (ex.InnerException == null)
            {
                return ex.Message;
            }
            else
            {
                return GetInnermostMessage(ex.InnerException);
            }
        }
        #endregion

        #region Helper Methods
        private string EncodeAuthorizationHeader()
        {
            var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(string.Concat(this.UserName, ":", this.Password));
            return System.Convert.ToBase64String(plainTextBytes);
        }

        private MessageResponse SendMsg(MessageObject messageObject)
        {
            try
            {
                using (var client = new HttpClient())
                {
                    client.Timeout = TimeSpan.FromMinutes(10);
                    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", this.AuthorizationHeader);
                    string request = JsonConvert.SerializeObject(messageObject);

                    var content = new StringContent(request, Encoding.UTF8, "application/json");
                    var response = client.PostAsync("https://restapi.gsm.co.za/send/sms", content).Result;
                    var contents = response.Content.ReadAsStringAsync().Result;

                    return new MessageResponse() { HttpStatusCode = response.StatusCode, Message = contents };
                }

            }
            catch (Exception ex)
            {
                return new MessageResponse() { HttpStatusCode = HttpStatusCode.InternalServerError, Message = "ERROR: " + GetInnermostMessage(ex) };
            }
        }
        #endregion
    }
}