using System;
using System.IO;

namespace Ant.Service.Utilities
{
    /// <summary>
    /// This class represents a Pop3 response message and
    /// is intended to be used as a base class for all other
    /// Pop3Response types.
    /// </summary>
    internal class Pop3Response
    {
        private byte[] _responseContents;
        /// <summary>
        /// Gets the response contents.
        /// </summary>
        /// <value>The response contents.</value>
        internal byte[] ResponseContents
        {
            get
            {
                return _responseContents;
            }
        }

        private bool _statusIndicator;
        /// <summary>
        /// Gets a value indicating whether message was <c>true</c> +OK or <c>false</c> -ERR
        /// </summary>
        /// <value><c>true</c> if [status indicator]; otherwise, <c>false</c>.</value>
        public bool StatusIndicator
        {
            get { return _statusIndicator; }
        }

        private string _hostMessage;
        /// <summary>
        /// Gets the host message.
        /// </summary>
        /// <value>The host message.</value>
        public string HostMessage
        {
            get { return _hostMessage; }
        }


        /// <summary>
        /// Initializes a new instance of the <see cref="Pop3Response"/> class.
        /// </summary>
        /// <param name="responseContents">The response contents.</param>
        /// <param name="hostMessage">The host message.</param>
        /// <param name="statusIndicator">if set to <c>true</c> [status indicator].</param>
        public Pop3Response(byte[] responseContents, string hostMessage, bool statusIndicator)
        {
            if (responseContents == null)
            {
                throw new ArgumentNullException("responseBuffer");
            }

            if (string.IsNullOrEmpty(hostMessage))
            {
                throw new ArgumentNullException("hostMessage");
            }

            _responseContents = responseContents;
            _hostMessage = hostMessage;
            _statusIndicator = statusIndicator;
        }

        /// <summary>
        /// Creates the response.
        /// </summary>
        /// <param name="responseContents">The response contents.</param>
        /// <returns></returns>
        public static Pop3Response CreateResponse(byte[] responseContents)
        {
            string hostMessage;
            MemoryStream stream = new MemoryStream(responseContents);
            using (StreamReader reader = new StreamReader(stream))
            {
                hostMessage = reader.ReadLine();

                if (hostMessage == null)
                {
                    return null;
                }

                bool success = hostMessage.StartsWith(Pop3Responses.Ok);

                return new Pop3Response(responseContents, hostMessage, success);
            }
        }
    }
}