﻿#region License
//The MIT License (MIT)

//Copyright (c) 2014 Doug Swisher

//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 Difftaculous.Paths;


namespace Difftaculous.Caveats
{
    internal class VarianceCaveat : ICaveat
    {
        private readonly double _allowance;


        public VarianceCaveat(DiffPath path, double allowance)
        {
            _allowance = allowance;
            Path = path;

            // TODO
        }


        public DiffPath Path { get; private set; }


        public bool IsAcceptable(string a, string b)
        {
            double ad;
            double bd;

            if (double.TryParse(a, out ad) && double.TryParse(b, out bd))
            {
                if (Math.Abs(ad - bd) < _allowance)
                {
                    return true;
                }
            }
            else
            {
                // TODO - should this emit a warning that they attempted to apply a numeric
                // caveat to something that isn't numeric?
                return false;
            }

            return false;
        }
    }
}
