using System;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

using System.Runtime.CompilerServices;

using System.Text;

using System.Threading.Tasks;

namespace JSONAPI.Core

{

public sealed class MetadataManager

{

#region Singleton pattern

private static readonly MetadataManager instance = new MetadataManager();

private MetadataManager() { }

public static MetadataManager Instance

{

get

{

return instance;

}

}

#endregion

private readonly ConditionalWeakTable<object, Dictionary<string, object>> cwt

= new ConditionalWeakTable<object, Dictionary<string, object>>();

/*

internal void SetDeserializationMetadata(object deserialized, Dictionary<string, object> meta)

{

cwt.Add(deserialized, meta);

}

*/

internal void SetMetaForProperty(object deserialized, PropertyInfo prop, object value)

{

Dictionary<string, object> meta;

if (!cwt.TryGetValue(deserialized, out meta))

{

meta = new Dictionary<string, object>();

cwt.Add(deserialized, meta);

}

if (!meta.ContainsKey(prop.Name)) // Temporary fix for non-standard Id reprecussions...this internal implementation will change soon anyway.

meta.Add(prop.Name, value);

}

internal Dictionary<String, object> DeserializationMetadata(object deserialized)

{

Dictionary<string, object> retval;

if (cwt.TryGetValue(deserialized, out retval))

{

return retval;

}

else

{

//TODO: Throw an exception here? If you asked for metadata for an object and it's not found, something has probably gone pretty badly wrong!

return null;

}

}

/// <summary>

/// Find whether or not a given property was

/// posted in the original JSON--i.e. to determine whether an update operation should be

/// performed, and/or if a default value should be used.

/// </summary>

/// <param name="deserialized">The object deserialized by JsonApiFormatter</param>

/// <param name="prop">The property to check</param>

/// <returns>Whether or not the property was found in the original JSON and set by the deserializer</returns>

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public bool PropertyWasPresent(object deserialized, PropertyInfo prop)

{

object throwaway;

return this.DeserializationMetadata(deserialized).TryGetValue(prop.Name, out throwaway);

}

}

}