using System;

using System.Collections.Generic;

using System.Collections.Specialized;

using System.Text;



namespace LumiSoft.Net.SIP.Message

{

    /// <summary>

    /// Implements SIP "accept-range" value. Defined in RFC 3261.

    /// </summary>

    /// <remarks>

    /// <code>

    /// RFC 3261 Syntax:

    ///     accept-range  = media-range [ accept-params ] 

    ///     media-range   = ("*//*" / (m-type SLASH "*") / (m-type SLASH m-subtype)) *(SEMI m-parameter)

    ///     accept-params = SEMI "q" EQUAL qvalue *(SEMI generic-param)

    /// </code>

    /// </remarks>

    public class SIP_t_AcceptRange : SIP_t_Value

    {

        private string                  m_MediaType        = "";

        private SIP_ParameterCollection m_pMediaParameters = null;

        private SIP_ParameterCollection m_pParameters      = null;



        /// <summary>

        /// Default constructor.

        /// </summary>

        public SIP_t_AcceptRange()

        {

            m_pMediaParameters = new SIP_ParameterCollection();

            m_pParameters      = new SIP_ParameterCollection();

        }





        #region method Parse



        /// <summary>

        /// Parses "accept-range" from specified value.

        /// </summary>

        /// <param name="value">SIP "accept-range" value.</param>

        /// <exception cref="ArgumentNullException">Raised when <b>value</b> is null.</exception>

        /// <exception cref="SIP_ParseException">Raised when invalid SIP message.</exception>

        public void Parse(string value)

        {

            if(value == null){

                throw new ArgumentNullException("value");

            }



            Parse(new StringReader(value));

        }



        /// <summary>

        /// Parses "accept-range" from specified reader.

        /// </summary>

        /// <param name="reader">Reader from where to parse.</param>

        /// <exception cref="ArgumentNullException">Raised when <b>reader</b> is null.</exception>

        /// <exception cref="SIP_ParseException">Raised when invalid SIP message.</exception>

        public override void Parse(StringReader reader)

        {            

            /*

                accept-range  = media-range [ accept-params ] 

                media-range   = ("*//*" / (m-type SLASH "*") / (m-type SLASH m-subtype)) *(SEMI m-parameter)

                accept-params = SEMI "q" EQUAL qvalue *(SEMI generic-param)

            */



            if(reader == null){

                throw new ArgumentNullException("reader");

            }



            // Parse m-type

            string word = reader.ReadWord();

            if(word == null){

                throw new SIP_ParseException("Invalid 'accept-range' value, m-type is missing !");

            }

            this.MediaType = word;



            // Parse media and accept parameters !!! thats confusing part, RFC invalid.

            bool media_accept = true;

            while(reader.Available > 0){

                reader.ReadToFirstChar();



                // We have 'next' value, so we are done here.

                if(reader.SourceString.StartsWith(",")){

                    break;

                }

                // We have parameter

                else if(reader.SourceString.StartsWith(";")){

                    reader.ReadSpecifiedLength(1);

                    string paramString = reader.QuotedReadToDelimiter(new char[]{';',','},false);

                    if(paramString != ""){

                        string[] name_value = paramString.Split(new char[]{'='},2);

                        string name  = name_value[0].Trim();

                        string value = "";

                        if(name_value.Length == 2){

                            value = name_value[1];

                        }



                        // If q, then accept parameters begin

                        if(name.ToLower() == "q"){

                            media_accept = false;

                        }



                        if(media_accept){

                            this.MediaParameters.Add(name,value);

                        }

                        else{

                            this.Parameters.Add(name,value);

                        }

                    }

                }

                // Unknown data

                else{

                    throw new SIP_ParseException("SIP_t_AcceptRange unexpected prarameter value !");

                }

            }

        }



        #endregion



        #region method ToStringValue



        /// <summary>

        /// Converts this to valid "accept-range" value.

        /// </summary>

        /// <returns>Returns "accept-range" value.</returns>

        public override string ToStringValue()

        {

            /*

                Accept        = "Accept" HCOLON [ accept-range *(COMMA accept-range) ]

                accept-range  = media-range [ accept-params ] 

                media-range   = ("*//*" / (m-type SLASH "*") / (m-type SLASH m-subtype)) *(SEMI m-parameter)

                accept-params = SEMI "q" EQUAL qvalue *(SEMI generic-param)

            */



            StringBuilder retVal = new StringBuilder();

            retVal.Append(m_MediaType);

            foreach(SIP_Parameter parameter in m_pMediaParameters){

                if(parameter.Value != null){

                    retVal.Append(";" + parameter.Name + "=" + parameter.Value);

                }

                else{

                    retVal.Append(";" + parameter.Name);

                }

            }

            foreach(SIP_Parameter parameter in m_pParameters){

                if(parameter.Value != null){

                    retVal.Append(";" + parameter.Name + "=" + parameter.Value);

                }

                else{

                    retVal.Append(";" + parameter.Name);

                }

            }



            return retVal.ToString();

        }



        #endregion





        #region Properties Implementation



        /// <summary>

        /// Gets or sets media type. Value *(STAR) means all values. Syntax: mediaType / mediaSubType.

        /// Examples: */*,video/*,text/html.

        /// </summary>

        public string MediaType

        {

            get{ return m_MediaType; }



            set{

                if(string.IsNullOrEmpty(value)){

                    throw new ArgumentException("Property MediaType value can't be null or empty !");

                }

                if(value.IndexOf('/') == -1){

                    throw new ArgumentException("Invalid roperty MediaType value, syntax: mediaType / mediaSubType !");

                }



                m_MediaType = value;

            }

        }



        /// <summary>

        /// Gets media parameters collection.

        /// </summary>

        /// <returns></returns>

        public SIP_ParameterCollection MediaParameters

        {

            get{ return m_pMediaParameters; }

        }



        /// <summary>

        /// Gets accept value parameters.

        /// </summary>

        public SIP_ParameterCollection Parameters

        {

            get{ return m_pParameters; }

        }



        /// <summary>

        /// Gets or sets qvalue parameter. Targets are processed from highest qvalue to lowest. 

        /// This value must be between 0.0 and 1.0. Value -1 means that value not specified.

        /// </summary>

        public double QValue

        {

            get{

                SIP_Parameter parameter = this.Parameters["qvalue"];

                if(parameter != null){

                    return Convert.ToDouble(parameter.Value);

                }

                else{

                    return -1;

                }

            }



            set{

                if(value < 0 || value > 1){

                    throw new ArgumentException("Property QValue value must be between 0.0 and 1.0 !");

                }



                if(value < 0){

                    this.Parameters.Remove("qvalue");

                }

                else{

                    this.Parameters.Set("qvalue",value.ToString());

                }

            }

        }



        #endregion



    }

}