/*
 *  Copyright 2006-2018 WebPKI.org (http://webpki.org).
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License 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.
 *
 */

// Ported to C# from the Mozilla "Rhino" project by Anders Rundgren.

using System;
using System.Text;

/// <summary>
/// This is the only public class of the ES6 compatible JSON Number serializer.
/// </summary>

namespace Org.Webpki.Es6NumberSerialization
{
    public static class NumberToJson
    {
        /*
         * Formats a JSON number according to ES6.
         * This code is emulating 7.1.12.1 of the EcmaScript V6 specification.
         */
        public static string SerializeNumber(double value)
        {
            // 1. Check for JSON compatibility.
            if (Double.IsNaN(value) || Double.IsInfinity(value))
            {
                throw new ArgumentException("NaN/Infinity are not permitted in JSON");
            }

            // 2.Deal with zero separately.  Note that this test takes "-0.0" as well
            if (value == 0.0)
            {
                return "0";
            }

            // 3. Call the DtoA algorithm crunchers
            // V8 FastDtoa can't convert all numbers, so try it first but
            // fall back to old DToA in case it fails
            String result = NumberFastDToA.NumberToString(value);
            if (result != null)
            {
                return result;
            }
            StringBuilder buffer = new StringBuilder();
            NumberDToA.JS_dtostr(buffer, NumberDToA.DTOSTR_STANDARD, 0, value);
            return buffer.ToString();
        }
    }
}