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

using LumiSoft.Net.IO;

namespace LumiSoft.Net.MIME
{
    /// <summary>
    /// This class represents MIME multipart/alternative body. Defined in RFC 2046 5.1.4.
    /// </summary>
    /// <remarks>
    /// The "multipart/alternative" is intended for use when each of the body parts is an "alternative" version of the same information.
    /// In general, user agents that compose "multipart/alternative" entities
    /// must place the body parts in increasing order of preference, that is,
    /// with the preferred format last.
    /// </remarks>
    public class MIME_b_MultipartAlternative : MIME_b_Multipart
    {
        /// <summary>
        /// Default constructor. The boundary = auto-generated.
        /// </summary>
        public MIME_b_MultipartAlternative() : base()
        {
            MIME_h_ContentType contentType_multipartAlternative = new MIME_h_ContentType(MIME_MediaTypes.Multipart.alternative);
            contentType_multipartAlternative.Param_Boundary = Guid.NewGuid().ToString().Replace('-','.');
            this.ContentType = contentType_multipartAlternative;
        }

        /// <summary>
        /// Default constructor.
        /// </summary>
        /// <param name="contentType">Content type.</param>
        /// <exception cref="ArgumentNullException">Is raised when <b>contentType</b> is null reference.</exception>
        /// <exception cref="ArgumentException">Is raised when any of the arguments has invalid value.</exception>
        public MIME_b_MultipartAlternative(MIME_h_ContentType contentType) : base(contentType)
        {
            if(!string.Equals(contentType.TypeWithSubtype,"multipart/alternative",StringComparison.CurrentCultureIgnoreCase)){
                throw new ArgumentException("Argument 'contentType.TypeWithSubype' value must be 'multipart/alternative'.");
            }
        }


        #region static method Parse

        /// <summary>
        /// Parses body from the specified stream
        /// </summary>
        /// <param name="owner">Owner MIME entity.</param>
        /// <param name="defaultContentType">Default content-type for this body.</param>
        /// <param name="stream">Stream from where to read body.</param>
        /// <returns>Returns parsed body.</returns>
        /// <exception cref="ArgumentNullException">Is raised when <b>stream</b>, <b>defaultContentType</b> or <b>stream</b> is null reference.</exception>
        /// <exception cref="ParseException">Is raised when any parsing errors.</exception>
        protected static new MIME_b Parse(MIME_Entity owner,MIME_h_ContentType defaultContentType,SmartStream stream)
        {
            if(owner == null){
                throw new ArgumentNullException("owner");
            }
            if(defaultContentType == null){
                throw new ArgumentNullException("defaultContentType");
            }
            if(stream == null){
                throw new ArgumentNullException("stream");
            }
            if(owner.ContentType == null || owner.ContentType.Param_Boundary == null){
                throw new ParseException("Multipart entity has not required 'boundary' paramter.");
            }
            
            MIME_b_MultipartAlternative retVal = new MIME_b_MultipartAlternative(owner.ContentType);
            ParseInternal(owner,owner.ContentType.TypeWithSubtype,stream,retVal);

            return retVal;
        }

        #endregion
        

        #region Properties implementation
                
        #endregion
    }
}
