//******************************************************************************************************
//  ApproximatelyEquals.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;
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 bool ApproximatelyEquals(this string source, string target, FuzzyStringComparisonOptions options, FuzzyStringComparisonTolerance tolerance)
        {
            List<double> comparisonResults = new List<double>();

            if (!options.HasFlag(FuzzyStringComparisonOptions.CaseSensitive))
            {
                source = source.Capitalize();
                target = target.Capitalize();
            }

            // Min: 0    Max: source.Length = target.Length
            if (options.HasFlag(FuzzyStringComparisonOptions.UseHammingDistance))
            {
                if (source.Length == target.Length)
                {
                    comparisonResults.Add(source.HammingDistance(target) / (double)target.Length);
                }
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseJaccardDistance))
            {
                comparisonResults.Add(source.JaccardDistance(target));
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseJaroDistance))
            {
                comparisonResults.Add(source.JaroDistance(target));
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseJaroWinklerDistance))
            {
                comparisonResults.Add(source.JaroWinklerDistance(target));
            }

            // Min: 0    Max: LevenshteinDistanceUpperBounds - LevenshteinDistanceLowerBounds
            // Min: LevenshteinDistanceLowerBounds    Max: LevenshteinDistanceUpperBounds
            if (options.HasFlag(FuzzyStringComparisonOptions.UseNormalizedLevenshteinDistance))
            {
                comparisonResults.Add(Convert.ToDouble(source.NormalizedLevenshteinDistance(target)) / Convert.ToDouble((Math.Max(source.Length, target.Length) - source.LevenshteinDistanceLowerBounds(target))));
            }
            else if (options.HasFlag(FuzzyStringComparisonOptions.UseLevenshteinDistance))
            {
                comparisonResults.Add(Convert.ToDouble(source.LevenshteinDistance(target)) / Convert.ToDouble(source.LevenshteinDistanceUpperBounds(target)));
            }

            if (options.HasFlag(FuzzyStringComparisonOptions.UseLongestCommonSubsequence))
            {
                comparisonResults.Add(1 - Convert.ToDouble((source.LongestCommonSubsequence(target).Length) / Convert.ToDouble(Math.Min(source.Length, target.Length))));
            }

            if (options.HasFlag(FuzzyStringComparisonOptions.UseLongestCommonSubstring))
            {
                comparisonResults.Add(1 - Convert.ToDouble((source.LongestCommonSubstring(target).Length) / Convert.ToDouble(Math.Min(source.Length, target.Length))));
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseSorensenDiceDistance))
            {
                comparisonResults.Add(source.SorensenDiceDistance(target));
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseOverlapCoefficient))
            {
                comparisonResults.Add(1 - source.OverlapCoefficient(target));
            }

            // Min: 0    Max: 1
            if (options.HasFlag(FuzzyStringComparisonOptions.UseRatcliffObershelpSimilarity))
            {
                comparisonResults.Add(1 - source.RatcliffObershelpSimilarity(target));
            }

            if (tolerance == FuzzyStringComparisonTolerance.Strong)
            {
                if (comparisonResults.Average() < 0.25)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            else if (tolerance == FuzzyStringComparisonTolerance.Normal)
            {
                if (comparisonResults.Average() < 0.5)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            else if (tolerance == FuzzyStringComparisonTolerance.Weak)
            {
                if (comparisonResults.Average() < 0.75)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            else if (tolerance == FuzzyStringComparisonTolerance.Manual)
            {
                if (comparisonResults.Average() > 0.6)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            else
            {
                return false;
            }
        }
    }
}