STUN Client

using System;
using System.Collections.Generic;
using System.Text;

namespace LumiSoft.Net.Mime.vCard
{
    /// <summary>
    /// vCard structure item.
    /// </summary>
    public class Item
    {
        private string m_Name       = "";
        private string m_Parameters = "";
        private string m_Value      = "";

        /// <summary>
        /// Default constructor.
        /// </summary>
        /// <param name="name">Item name.</param>
        /// <param name="parameters">Item parameters.</param>
        /// <param name="value">Item encoded value value.</param>
        internal Item(string name,string parameters,string value)
        {
            m_Name       = name;
            m_Parameters = parameters;
            m_Value      = value;
        }


        #region method SetDecodedValue

        /// <summary>
        /// Sets item decoded value. Value will be encoded as needed and stored to item.Value property.
        /// Also property item.ParametersString is updated to reflect right encoding(always base64, required by rfc) and charset (utf-8).
        /// </summary>
        /// <param name="value"></param>
        public void SetDecodedValue(string value)
        {
            /* RFC 2426 vCrad 5. Differences From vCard v2.1
                The QUOTED-PRINTABLE inline encoding has been eliminated.
                Only the "B" encoding of [RFC 2047] is an allowed value for
                the ENCODING parameter.
              
                The CRLF character sequence in a text type value is specified 
                with the backslash character sequence "\n" or "\N".
             
                Any COMMA or SEMICOLON in a text type value must be backslash escaped.
            */

            // FIX ME: this must be done with structured fields
            //value = value.Replace("\r\n","\n").Replace("\n","\\n");
            //value = TextUtils.EscapeString(value,new char[]{',',';'});

            bool needEncode = false;
            if(!Core.IsAscii(value)){
                needEncode = true;
            }

            if(needEncode){
                // Remove encoding and charset parameters
                string newParmString = "";
                string[] parameters = m_Parameters.ToLower().Split(';');
                foreach(string parameter in parameters){
                    string[] name_value = parameter.Split('=');
                    if(name_value[0] == "encoding" || name_value[0] == "charset"){                        
                    }
                    else if(parameter.Length > 0){
                        newParmString += parameter + ";";
                    }
                }
                // Add encoding parameter
                newParmString += "ENCODING=b;CHARSET=utf-8";
      
                this.ParametersString = newParmString;
                this.Value = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(value));
            }
            else{
                this.Value = value;
            }
        }

        #endregion


        #region internal method ToItemString

        /// <summary>
        /// Converts item to vCal item string.
        /// </summary>
        /// <returns></returns>
        internal string ToItemString()
        {
            if(m_Parameters.Length > 0){
                return m_Name + ";" + m_Parameters + ":" + MimeUtils.FoldData(m_Value);
            }
            else{
                return m_Name + ":" + MimeUtils.FoldData(m_Value);
            }
        }

        #endregion


        #region Properties Implementation

        /// <summary>
        /// Gest item name.
        /// </summary>
        public string Name
        {
            get{ return m_Name; }
        }

        /// <summary>
        /// Gets or sets item parameters.
        /// </summary>
        public string ParametersString
        {
            get{ return m_Parameters; }

            set{ m_Parameters = value; }
        }

        /// <summary>
        /// Gets or sets item encoded value. NOTE: If you set this property value, you must encode data 
        /// by yourself and also set right ENCODING=encoding; and CHARSET=charset; prameter in item.ParametersString !!!
        /// Normally use method item.SetDecodedStringValue method instead, this does all you need.
        /// </summary>
        public string Value
        {
            get{ return m_Value; }

            set{ m_Value = value; }
        }

        /// <summary>
        /// Gets item decoded value. If param string specifies Encoding and/or Charset, 
        /// item.Value will be decoded accordingly.
        /// </summary>
        public string DecodedValue
        {
            /* RFC 2426 vCrad 5. Differences From vCard v2.1              
                The CRLF character sequence in a text type value is specified 
                with the backslash character sequence "\n" or "\N".
             
                Any COMMA or SEMICOLON in a text type value must be backslash escaped.
            */

            get{ 
                string data     = m_Value;
                string encoding = null;
                string charset  = null;
                string[] parameters = m_Parameters.ToLower().Split(';');
                foreach(string parameter in parameters){
                    string[] name_value = parameter.Split('=');
                    if(name_value[0] == "encoding" && name_value.Length > 1){
                        encoding = name_value[1];
                    }
                    else if(name_value[0] == "charset" && name_value.Length > 1){
                        charset = name_value[1];
                    }
                }

                // Encoding specified, decode data.
                if(encoding != null){
                    if(encoding == "quoted-printable"){
                        data = System.Text.Encoding.Default.GetString(Core.QuotedPrintableDecode(System.Text.Encoding.Default.GetBytes(data)));
                    }
                    else if(encoding == "b"){
                        data = System.Text.Encoding.Default.GetString(Core.Base64Decode(System.Text.Encoding.Default.GetBytes(data)));
                    }
                    else{
                        throw new Exception("Unknown data encoding '" + encoding + "' !");
                    }
                }
                // Charset specified, convert data to specified charset.
                if(charset != null){
                    data = System.Text.Encoding.GetEncoding(charset).GetString(System.Text.Encoding.Default.GetBytes(data));
                }

                // FIX ME: this must be done with structured fields
                //data = data.Replace("\\n","\r\n");
                //data = TextUtils.UnEscapeString(data); Messes up structured fields

                return data; 
            }
        }

        #endregion

    }
}