/*

* This file is part of SharpMap.Rendering.GeoJson

* SharpMap.Rendering.GeoJson is free software © 2008 Newgrove Consultants Limited,

* http://www.newgrove.com; you can redistribute it and/or modify it under the terms

* of the current GNU Lesser General Public License (LGPL) as published by and

* available from the Free Software Foundation, Inc.,

* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA: http://fsf.org/

* This program is distributed without any warranty;

* without even the implied warranty of merchantability or fitness for purpose.

* See the GNU Lesser General Public License for the full details.

*

* Author: John Diss 2008

*

*/

using System;

using System.Collections;

using System.Collections.Generic;

using System.Text;

using GeoAPI.DataStructures;

#if DOTNET35

using Enumerable = System.Linq.Enumerable;

using Caster = System.Linq.Enumerable;

#else

#endif

namespace SharpMap.Rendering.GeoJson

{

public static class JsonUtility

{

private static readonly Type[] FloatingPointTypes = new[] {typeof (float), typeof (double), typeof (decimal)};

private static readonly Type[] IntegralTypes = new[]

{

typeof (UInt16), typeof (UInt32), typeof (UInt64),

typeof (Int16), typeof (Int32), typeof (Int64)

};

public static string FormatJsonAttribute(string name, object value)

{

return string.Format("\"{0}\":{1}", name, FormatJsonValue(value));

}

private static string FormatJsonValue(object v)

{

if (v == null || v is DBNull)

return "null";

Type tval = v.GetType();

if (tval != typeof (string) && typeof (IEnumerable).IsAssignableFrom(tval))

{

StringBuilder sb = new StringBuilder();

sb.Append("[");

IList<string> store = new List<string>();

foreach (object o in (IEnumerable) v)

store.Add(FormatJsonValue(o));

for (int i = 0; i < store.Count; i++)

{

sb.Append(store[i]);

if (i < store.Count - 2)

sb.Append(",");

}

sb.Append("]");

return sb.ToString();

}

if (tval.IsPrimitive)

{

if (tval == typeof (bool))

return v.ToString().ToLower();

if (Enumerable.Contains(IntegralTypes, tval))

return v.ToString();

if (Enumerable.Contains(FloatingPointTypes, tval))

return string.Format("{0:E}", v);

}

if (tval == typeof (string) || tval == typeof (Char))

return string.Format("\"{0}\"", HttpUtility.HtmlEncode((string) v));

///todo : more complex classes

throw new FormatException();

}

}

}