#region
/* -----------------------------------------------------------------------
 * <copyright file="PermissionConverter.cs" company="GRNet">
 * 
 * Copyright 2011-2012 GRNET S.A. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 *   1. Redistributions of source code must retain the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials
 *      provided with the distribution.
 *
 *
 * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and
 * documentation are those of the authors and should not be
 * interpreted as representing official policies, either expressed
 * or implied, of GRNET S.A.
 * </copyright>
 * -----------------------------------------------------------------------
 */
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Newtonsoft.Json;

namespace Pithos.Interfaces
{
    public class PermissionConverter:JsonConverter
    {
        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            var dict = (Dictionary<string, string>) value;
            var pairs = from pair in dict
                        group pair by pair.Value into g
                        select new {Permission=g.Key,Names=String.Join(",", g.SelectMany(p=>p.Key))};

            var result=pairs.Aggregate(new StringBuilder(),
                                       (builder, perm) => 
                                       builder.AppendFormat("{0}={1};", perm.Permission, perm.Names));

            var finalValue = result.ToString();
            writer.WriteValue(finalValue);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            
            var permissionString= (string) reader.Value;

            var permissions = (from permisson in permissionString.Split(';')
                               let parsed = permisson.Split('=')
                               from account in parsed[1].Split(',')
                               select new { account, Permission = parsed[0] })
                .ToDictionary(perm=>perm.account,perm=>perm.Permission);

            return permissions;
        }

        public override bool CanConvert(Type objectType)
        {
            return (objectType==typeof(Dictionary<string,string>));
        }
    }
}