// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.


using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using Microsoft.AspNet.Http.Authentication;
using Microsoft.Framework.Internal;

namespace Microsoft.AspNet.Authentication.DataHandler.Serializer
{
    public class PropertiesSerializer : IDataSerializer<AuthenticationProperties>
    {
        private const int FormatVersion = 1;

        [SuppressMessage("Microsoft.Usage", "CA2202:Do not dispose objects multiple times", Justification = "Dispose is idempotent")]
        public byte[] Serialize(AuthenticationProperties model)
        {
            using (var memory = new MemoryStream())
            {
                using (var writer = new BinaryWriter(memory))
                {
                    Write(writer, model);
                    writer.Flush();
                    return memory.ToArray();
                }
            }
        }

        [SuppressMessage("Microsoft.Usage", "CA2202:Do not dispose objects multiple times", Justification = "Dispose is idempotent")]
        public AuthenticationProperties Deserialize(byte[] data)
        {
            using (var memory = new MemoryStream(data))
            {
                using (var reader = new BinaryReader(memory))
                {
                    return Read(reader);
                }
            }
        }

        public static void Write([NotNull] BinaryWriter writer, [NotNull] AuthenticationProperties properties)
        {
            writer.Write(FormatVersion);
            writer.Write(properties.Dictionary.Count);
            foreach (var kv in properties.Dictionary)
            {
                writer.Write(kv.Key);
                writer.Write(kv.Value);
            }
        }

        public static AuthenticationProperties Read([NotNull] BinaryReader reader)
        {
            if (reader.ReadInt32() != FormatVersion)
            {
                return null;
            }
            int count = reader.ReadInt32();
            var extra = new Dictionary<string, string>(count);
            for (int index = 0; index != count; ++index)
            {
                string key = reader.ReadString();
                string value = reader.ReadString();
                extra.Add(key, value);
            }
            return new AuthenticationProperties(extra);
        }
    }
}