#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections.Generic;
using System.Text;

namespace LC.Newtonsoft.Json.Utilities
{
    internal static class MathUtils
    {
        public static int IntLength(ulong i)
        {
            if (i < 10000000000)
            {
                if (i < 10)
                {
                    return 1;
                }
                if (i < 100)
                {
                    return 2;
                }
                if (i < 1000)
                {
                    return 3;
                }
                if (i < 10000)
                {
                    return 4;
                }
                if (i < 100000)
                {
                    return 5;
                }
                if (i < 1000000)
                {
                    return 6;
                }
                if (i < 10000000)
                {
                    return 7;
                }
                if (i < 100000000)
                {
                    return 8;
                }
                if (i < 1000000000)
                {
                    return 9;
                }

                return 10;
            }
            else
            {
                if (i < 100000000000)
                {
                    return 11;
                }
                if (i < 1000000000000)
                {
                    return 12;
                }
                if (i < 10000000000000)
                {
                    return 13;
                }
                if (i < 100000000000000)
                {
                    return 14;
                }
                if (i < 1000000000000000)
                {
                    return 15;
                }
                if (i < 10000000000000000)
                {
                    return 16;
                }
                if (i < 100000000000000000)
                {
                    return 17;
                }
                if (i < 1000000000000000000)
                {
                    return 18;
                }
                if (i < 10000000000000000000)
                {
                    return 19;
                }

                return 20;
            }
        }

        public static char IntToHex(int n)
        {
            if (n <= 9)
            {
                return (char)(n + 48);
            }

            return (char)((n - 10) + 97);
        }

        public static int? Min(int? val1, int? val2)
        {
            if (val1 == null)
            {
                return val2;
            }
            if (val2 == null)
            {
                return val1;
            }

            return Math.Min(val1.GetValueOrDefault(), val2.GetValueOrDefault());
        }

        public static int? Max(int? val1, int? val2)
        {
            if (val1 == null)
            {
                return val2;
            }
            if (val2 == null)
            {
                return val1;
            }

            return Math.Max(val1.GetValueOrDefault(), val2.GetValueOrDefault());
        }

        public static double? Max(double? val1, double? val2)
        {
            if (val1 == null)
            {
                return val2;
            }
            if (val2 == null)
            {
                return val1;
            }

            return Math.Max(val1.GetValueOrDefault(), val2.GetValueOrDefault());
        }

        public static bool ApproxEquals(double d1, double d2)
        {
            const double epsilon = 2.2204460492503131E-16;

            if (d1 == d2)
            {
                return true;
            }

            double tolerance = ((Math.Abs(d1) + Math.Abs(d2)) + 10.0) * epsilon;
            double difference = d1 - d2;

            return (-tolerance < difference && tolerance > difference);
        }
    }
}