//******************************************************************************************************
//  JaroDistance.cs - Gbtc
//
//  Copyright © 2013, Grid Protection Alliance.  All Rights Reserved.
//
//  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See
//  the NOTICE file distributed with this work for additional information regarding copyright ownership.
//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may
//  not use this file except in compliance with the License. You may obtain a copy of the License at:
//
//      http://www.opensource.org/licenses/MIT
//
//  Unless agreed to in writing, the subject software distributed under the License is distributed on an
//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the
//  License for the specific language governing permissions and limitations.
//
//  Code Modification History:
//  ----------------------------------------------------------------------------------------------------
//  04/14/2013 - Kevin D. Jones
//       Generated original version of source code.
//
//******************************************************************************************************

using System.Collections.Generic;
using System.Linq;

// TODO: Please add comments to these classes
#pragma warning disable 1591

namespace GSF.FuzzyStrings
{
    public static partial class ComparisonMetrics
    {
        public static double JaroDistance(this string source, string target)
        {
            int m = source.Intersect(target).Count();

            if (m == 0)
                return 0;

            string sourceTargetIntersetAsString = "";
            string targetSourceIntersetAsString = "";

            IEnumerable<char> sourceIntersectTarget = source.Intersect(target);
            IEnumerable<char> targetIntersectSource = target.Intersect(source);

            foreach (char character in sourceIntersectTarget)
            {
                sourceTargetIntersetAsString += character;
            }

            foreach (char character in targetIntersectSource)
            {
                targetSourceIntersetAsString += character;
            }

            double t = sourceTargetIntersetAsString.LevenshteinDistance(targetSourceIntersetAsString) / 2.0D;

            return ((m / source.Length) + (m / target.Length) + ((m - t) / m)) / 3;
        }
    }
}