﻿/******************************************************************************
* The MIT License
* Copyright (c) 2003 Novell Inc.  www.novell.com
*
* Permission is hereby granted, free of charge, to any person obtaining  a copy
* of this software and associated documentation files (the Software), to deal
* in the Software without restriction, including  without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to  permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*******************************************************************************/

using System;
using System.IO;
using System.Text;

namespace Novell.Directory.Ldap.Asn1
{
    /// <summary> This is the base class for all other Asn1 types.</summary>
    public abstract class Asn1Object
    {
        private Asn1Identifier _id;

        protected Asn1Object(Asn1Identifier id)
        {
            _id = id;
        }

        /// <summary>
        ///     Abstract method that must be implemented by each child
        ///     class to encode itself ( an Asn1Object) directly intto
        ///     a output stream.
        /// </summary>
        /// <param name="out">
        ///     The output stream onto which the encoded
        ///     Asn1Object will be placed.
        /// </param>
        public abstract void Encode(IAsn1Encoder enc, Stream outRenamed);

        /// <summary>
        ///     Returns the identifier for this Asn1Object as an Asn1Identifier.
        ///     This Asn1Identifier object will include the CLASS, FORM and TAG
        ///     for this Asn1Object.
        /// </summary>
        public virtual Asn1Identifier GetIdentifier()
        {
            return _id;
        }

        /// <summary>
        ///     Sets the identifier for this Asn1Object. This is helpful when
        ///     creating implicit Asn1Tagged types.
        /// </summary>
        /// <param name="id">
        ///     An Asn1Identifier object representing the CLASS,
        ///     FORM and TAG).
        /// </param>
        public virtual void SetIdentifier(Asn1Identifier id)
        {
            _id = id;
        }

        /// <summary>
        ///     This method returns a byte array representing the encoded
        ///     Asn1Object.  It in turn calls the encode method that is
        ///     defined in Asn1Object but will usually be implemented
        ///     in the child Asn1 classses.
        /// </summary>
        public byte[] GetEncoding(IAsn1Encoder enc)
        {
            var outRenamed = new MemoryStream();
            try
            {
                Encode(enc, outRenamed);
            }
            catch (IOException e)
            {
                // Should never happen - the current Asn1Object does not have
                // a encode method.
                throw new Exception("IOException while encoding to byte array: " + e);
            }

            return outRenamed.ToArray();
        }

        /// <summary> Return a String representation of this Asn1Object.</summary>
        public override string ToString()
        {
            string[] classTypes = { "[UNIVERSAL ", "[APPLICATION ", "[", "[PRIVATE " };

            var sb = new StringBuilder();
            var id = GetIdentifier(); // could be overridden.

            sb.Append(classTypes[id.Asn1Class]).Append(id.Tag).Append("] ");

            return sb.ToString();
        }
    }
}
