/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 * 
 *  http://aws.amazon.com/apache2.0
 * 
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace Amazon.S3.Encryption
{
    /// <summary>
    /// The "key encrypting key" materials used in encrypt/decryption.
    /// These materials may be an asymmetric key, a symmetric key, or a KMS key ID.
    /// </summary>
    public class EncryptionMaterials
    {

        private Dictionary<string, string> materialsDescription;

        /// <summary>
        /// Constructs a new EncryptionMaterials object, storing an asymmetric key.
        /// </summary>
        /// <param name="algorithm"></param>
        public EncryptionMaterials(AsymmetricAlgorithm algorithm) : this(algorithm, null, null)
        {
        }

        /// <summary>
        /// Constructs a new EncryptionMaterials object, storing a symmetric key.
        /// </summary>
        /// <param name="algorithm"></param>
        public EncryptionMaterials(SymmetricAlgorithm algorithm) : this(null, algorithm, null)
        {
        }

        /// <summary>
        /// Constructs a new EncryptionMaterials object, storing a KMS Key ID
        /// </summary>
        /// <param name="kmsKeyID"></param>
        public EncryptionMaterials(string kmsKeyID) : this(null, null, kmsKeyID)
        {
            materialsDescription.Add(EncryptionUtils.KMSCmkIDKey, kmsKeyID);
        }

        private EncryptionMaterials(AsymmetricAlgorithm asymmetricAlgorithm, SymmetricAlgorithm symmetricAlgorithm, string kmsKeyID)
        {
            AsymmetricProvider = asymmetricAlgorithm;
            SymmetricProvider = symmetricAlgorithm;
            KMSKeyID = kmsKeyID;
            materialsDescription = new Dictionary<string, string>();
        }

        internal AsymmetricAlgorithm AsymmetricProvider { get; private set; }

        internal SymmetricAlgorithm SymmetricProvider { get; private set; }

        internal string KMSKeyID { get; private set; }

        internal Dictionary<string, string> MaterialsDescription
        {
            get
            {
                return materialsDescription;
            }
        }
    }
}