using System;

using CSharpFunctionalExtensions;

using System.Text.RegularExpressions;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        (string name, string culture)[] nameTests = {/**/

                        /**/ ("Sônia de Hollanda Zakaria - Recibo oficial março2021 - PJ.docx", "pt-BR")

                        , ("Laudo médico com afastamento por 2 meses 13042021.pdf", "pt-BR")

                        , ("Laudo médico com afastamento por 2 meses .pdf", "pt-BR")

                        , ("Laudo médico com afastamento por 100 dias.pdf", "pt-BR")

                        , ("Prontuário Itau com anotações entre 2007 e 2021.pdf", "pt-BR")

                        , ("Recibos comparecimento a Fisioterapia entre 052016 e 122019.pdf", "pt-BR")

                        , ("US abdominal˗cisto hepático_5f9a739a-0b2e-4fcc-9228-81035e6e50ea 23122022 v3.docx", "pt-BR")

                        , ("Ruy Quiroga_20230605161406.pdf", "pt-BR")

                        , ("Aderaldo Vieira Chaves - SOLICITAÇÃO DE EXAME_5f9a739a-0b2e-4fcc-9228-81035e6e50ea.pdf", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo 3 - 23122022.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo - 23122022 2.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo - 122022 2.docx", "pt-BR")

                        , ("Nome do paciente - relatório internação de 12 a 20122022 - 2 20__.docx", "pt-BR")

                        , ("Nome do paciente - relatório internação de 12 a 20122022 - 2 2017.docx", "pt-BR")

                        , ("Nome do paciente - relatório internação de 12 a 20122022 - v2 2017.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo - 23122022 v2.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo v3 - 23122022.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo - 122022 v2.docx", "pt-BR")

                        , ("Nome do paciente - relatório internação de 12 a 20122022 - v2 20__.docx", "pt-BR")

                        , ("US abdominal-cisto hepático 23122022.docx", "pt-BR"), ("US abdominal˗cisto hepático 23122022.docx", "pt-BR")

                        , ("US abdominal–cisto hepático 23122022.docx", "pt-BR")

                        , ("US abdominal - cisto hepático 23122022.docx", "pt-BR"), ("US abdominal - cisto hepático v3 23122022.doc", "pt-BR")

                        , ("US abdominal 23122022.docx", "pt-BR")

                        , ("US abdominal - 23122022.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo v2 - 23122022.docx", "pt-BR")

                        , ("Nome do paciente - v2 23122022.docx", "pt-BR")

                        , ("Outro paciente - exame laboratorial amplo para home-care - v2 23122022.docx", "pt-BR")

                        , ("Nome do paciente - relatório internação de 12 a 20122022 - v2 23122022.docx", "pt-BR")

                        , ("Nome do paciente - exame laboratorial amplo - 202_ v3.docx", "pt-BR")

                        , ("Nome do paciente D'Oliveira - RECEITUÁRIO CONTROLE ESPECIAL - Ciprofloxacino 500 mg 2017.pdf", "pt-BR"), ("Fulano Sicrano Beltrano - relatório internação - de 1208 até 20062021 - erosão traqueal - v2 12072021.docx", "pt-BR")

                        , ("Paulo Afonso Zavataro - Recibo PF referente ao período de 06 a 11082023 internação no Hospital Copa Star.pdf", "pt-BR")

                        , ("Paulo Afonso Zavataro - Recibo PJ referente ao período de 12 a 17082023 internação no Hospital Copa Star - NFSe_00003478_02874440.pdf", "pt-BR")

                        , ("Paulo Afonso Zavataro - Relatório e Recibo PF referente ao período de 06 a 11082023 internação no Hospital Copa Star - 77d93944-071c-4f01-8788-838d2a204a3d.pdf", "pt-BR")

                        , ("Waldenice de Albuquerque Haidamus - Relatório da internação entre 3005 a 14062013.docx", "pt-BR")

                        , ("Miuza de Holanda Fragelli - anotação Outlook_backup_2013_abr._20__13_38_12.pdf", "pt-BR")

                        , ("Miuza de Holanda Fragelli - anotação Outlook_backup_2013_apr_20__13_38_12.pdf", "en-US")

                        , ("Miuza de Holanda Fragelli - anotação Outlook_backup_2013_abr_20__13_38_12.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - 23.05.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - 05.23.pdf", "en-US")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - 23.5.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - 5.23.pdf", "en-US")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - apr2005.pdf", "en-US")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - abr.2005.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - abr2005.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - march2021.pdf", "en-US")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - march.2021.pdf", "en-US")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - março2021.pdf", "pt-BR")

                        , ("CARLOS ANTONIO MENEZES AMARAL BARBOSA - março.2021.pdf", "pt-BR")

                        , ("Nome do paciente D'Oliveira - RECEITUÁRIO CONTROLE ESPECIAL_5f9a739a-0b2e-4fcc-9228-81035e6e50ea durante internação Copa D'Or de 12 a 15052017 - Ciprofloxacino 500 mg 3 2017.pdf", "pt-BR")/**/

                        };

        foreach (var fileName in nameTests)

        {

            Console.WriteLine($"// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^");

            Console.WriteLine($"// Matches for {fileName.name}:");

            IterateMatches("GrabDatesWithMonthsInLettersOrPureNumbersFromFile", DocNameHelper.GrabDatesWithMonthsInLettersOrPureNumbersFromFile, fileName.name);

            IterateMatches("GrabDateIntervalFromPartOfFile", DocNameHelper.GrabDateIntervalFromPartOfFile, fileName.name);

            IterateMatches("GrabDatesIncorrectFormattedWithInvalidChars", DocNameHelper.GrabDatesIncorrectFormattedWithInvalidChars, fileName.name);

            IterateMatches("GrabDatesIncorrectFormattedWithInvalidChars", DocNameHelper.GrabFullMonthWithTwoOrFourDigitYearWithSomeCharSeparatingThemOrNot, fileName.name);

            IterateMatches("GrabAbbreviatedMonthWithTwoOrFourDigitYearWithDotSeparatingThemOrNot", DocNameHelper.GrabAbbreviatedMonthWithTwoOrFourDigitYearWithDotSeparatingThemOrNot, fileName.name);

            IterateMatches("GrabDatesOrPureNumbersOrDatesWithCardFromPartOfFile", DocNameHelper.GrabDatesOrPureNumbersOrDatesWithCardFromPartOfFile, fileName.name);

        }

    }

​

    internal static void IterateMatches(string namePattern, string pattern, string testCase)

    {

        var matches = DocNameHelper.GetMatches(pattern, testCase);

        Console.WriteLine($"// Matches for {namePattern}: {matches.Count}");

        List<Dictionary<string, string>> capturesDict = DocNameHelper.GetAllMatchesWithNamedGroups(matches);

        Result<List<List<(string namedGroup, string value)>>> capturesList = DocNameHelper.ReturnAllResults(matches);

        //var captures = DocNameHelper.ReturnResults(matches);

        if (capturesList.IsSuccess)

        {

            foreach (var capture in capturesList.Value)

            {

                if (capture.Any())

                {

                    Console.WriteLine("\n $$$$$$$$$$$$$$$$$$ from capturesList: $$$$$$$$$$$$$$$$$$");

                    capture.Dump();

                }

            }

        }

​

        Console.WriteLine("\n ############ from capturesDict: ############");

        capturesDict.Dump();

    //capturesList.Dump();

    }

}

​

public static class DocNameHelper

{

    /// <summary>

    /// Should check for equality between relationandinterval and intervalordate; if so, the interval is invalid and should be ignored

    /// </summary>

    internal const string GrabDatesWithMonthsInLettersOrPureNumbersFromFile = @"(?<relationandinterval>(?<temporalrelation> em | por )?(?<=\W)(?<intervalordate>(?:\d{6,8}|\d{2,3}_{1,2})|(?:\b(0?[1-9]|[12][0-9]|3[01])*(?: de )?([JFMASONDjfmasond]([a-z0-9]+)([ç]{0,1})([a-z0-9]+)*)*(?: de )?(19|20)?[0-9]{1}\b))(?<timeframe> anos[ .]{0,1}| ano[ .]{0,1}| meses[ .]{0,1}| mês[ .]{0,1}| dias[ .]{0,1}| dia[ .]{0,1})?)";

    ////https://regex101.com/r/ZuUZy3/16^^^^^^^^^^^^

    //private const string GrabDatesWithMonthsInLettersOrPureNumbersFromFile = @"(?<relationandinterval>(?<temporalrelation> em | por )?(?<=\W)(?<intervalordate>(?:\d{6,8}|\d{2,3}_{1,2})|(?:\b(0?[1-9]|[12][0-9]|3[01])*(?: de )?([JFMASONDjfmasond]([a-z0-9]+)([ç]{0,1})([a-z0-9]+)*)*(?: de )?(19|20)?[0-9]{1}\b))(?<timeframe> anos[ .]{0,1}| ano[ .]{0,1}| mês[ .]{0,1}| meses[ .]{0,1}| dias[ .]{0,1}| dia[ .]{0,1})?)";

    ////https://regex101.com/r/ZuUZy3/14^^^^^^^^^^^^

    //private const string GrabDatesWithMonthsInLettersOrPureNumbersFromFile = @"(?<relationandinterval>(?<temporalrelation> em | por )?(?<=\W)(?<intervalordate>(?:\d{6,8}|\d{2,3}_{1,2})|(?:\b(0?[1-9]|[12][0-9]|3[01])*(?: de )?([JFMASONDjfmasond]([a-z0-9]+)([ç]{0,1})([a-z0-9]+)*)*(?: de )?(19|20)?[0-9]{2}\b))(?<timeframe> ano | anos | mês | meses | dia | dias )?)";

    //https://regex101.com/r/ZuUZy3/11^^^^^^^^^^^^

    //https://stackoverflow.com/a/10033196/2752308 ^^^^^^ 

    internal const string GrabDatesOrPureNumbersOrDatesWithCardFromPartOfFile = @"(?<date>\d{6,8}|\d{2,3}_{1,2})";

    //https://regex101.com/r/wGCR0g/2 ^^^^^^^^^^^^^^^^^^^^^^^^^^       20__ or 202_  ^^^^^^^^^

    /// <summary>

    /// Some Dates, as from Bronstein, are formatted with WildCardForDate, like Laudo Completo 18_07_2023.pdf

    /// </summary>

    internal const string GrabDatesIncorrectFormattedWithInvalidChars = @"(?<![_.]{1})(?<date>\d{2}[_.]{1}\d{2}[_.]{1}(?:\d{4}|\d{2}))"; //(?<date>\d{2}[_.]{1}\d{2}[_.]{1}\d{4})";

    //https://regex101.com/r/pCbR7k/3 ^^^^^^^^^^^^^^^^^^^^^^^^^^

    internal const string GrabDatesUTC = @"(?<dateUTC>(?<year>-?(?:[1-9][0-9]*)?[0-9]{4})-(?<month>1[0-2]|0[1-9])-(?<day>3[01]|0[1-9]|[12][0-9])T(?<hour>2[0-3]|[01][0-9]):(?<minute>[0-5][0-9]):(?<second>[0-5][0-9])(\\.[0-9]+)?(?<zeroUTCoffse>Z)?|(?<year>(?:[1-9][0-9]*)?[0-9]{4})(?<month>1[0-2]|0[1-9])(?<day>3[01]|0[1-9]|[12][0-9])(?<hour>2[0-3]|[01][0-9])(?<minute>[0-5][0-9])(?<second>[0-5][0-9])(\\.[0-9]+)?(?<zeroUTCoffse>Z)?)";

    //https://regex101.com/r/DfGFk5/1 ^^^^^^^^^^^^^^^^^^^^^ https://www.utctime.net/ 

    //Use it only to extract from PartOfName

    //private const string GrabDateIntervalFromPartOfFile = @"(?<=\W)(?<interval>(?<starting>[ mçinícandouetr]+?)(?<datebegin>\d+)(?<link>[ eatéfimnldzou]+?)(?<=\W)(?<!\w-)(?<dateend>\d+))";

    ////https://regex101.com/r/1UfbIM/1 ^^^^^^^^^^^^^^^^ 

    internal const string GrabDateIntervalFromPartOfFile = @"(?<=\W)(?<interval>(?<starting>[ mçinícandouetr]+?)(?<datebegin>\d{2,8}|\d{14}(?!\d))(?<link>[ eatéfimnldzou]+?)(?<=\W)(?<!\w-)(?<dateend>\d{4,8}|\d{14})(?!\d))";

    //https://regex101.com/r/1UfbIM/3 ^^^^^^^^^^^^^^^^ 

    internal const string GrabDateAndVersionDotAtEnd = @"(?<date>\d{6,8}|\d{2,3}_{1,2}) {1,2}(?<version>[vVersionão]+[\d@]+[\w@]*|[\d@]+[vVersionão]+[\w@]*).|(?<version>[vVersionão]+[\d@]+[\w@]*|[\d@]+[vVersionão]+[\w@]*) {1,2}(?<date>\d{6,8}|\d{2,3}_{1,2})\.|(?<date>\d{6,8}|\d{2,3}_{1,2})\.";

    //https://regex101.com/r/TpTA1n/2 ^^^^^^^^^^^^^^^^

    internal const string GrabDatePersonalizedForAnotaçãoOutlookBackup = @"backup_(?<date>(?<yyyy>(?:19|20)[0-9]{2})_(?<MMM>[JFMASONDjfmasond]{1}[aeiouAEIOUnNvVrRbBlLgGtTzZpPyYcC]{2})_(?<dd>0[1-9]|[12][0-9]|3[01])__(?<hh>0?[0-9]|[1][0-9]|[2][0-3])_(?<mm>[0-9]{2})_(?<ss>[0-9]{2}))";

    //https://regex101.com/r/KESkRm/5 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    internal const string GrabDatePersonalizedForAnotaçãoOutlookBackupWithDotAfterMMM = @"backup_(?<date>(?<yyyy>(?:19|20)[0-9]{2})_(?<MMM>[JFMASONDjfmasond]{1}[aeiouAEIOUnNvVrRbBlLgGtTzZpPyYcC]{2})._(?<dd>0[1-9]|[12][0-9]|3[01])__(?<hh>0?[0-9]|[1][0-9]|[2][0-3])_(?<mm>[0-9]{2})_(?<ss>[0-9]{2}))";

    //https://regex101.com/r/qF6UKF/1 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    internal const string GrabAbbreviatedMonthWithTwoOrFourDigitYearWithDotSeparatingThemOrNot = @"(?<date>(?<datewithdot>(?<MMM>jan|fev|feb|mar|abr|apr|mai|may|jun|jul|ago|aug|set|sep|out|oct|nov|dez|dec)\.(?<yyyy>(?:19|20){0,1}[0-9]{2}))|(?<datewithoutdot>(?<MMM>jan|fev|feb|mar|abr|apr|mai|may|jun|jul|ago|aug|set|sep|out|oct|nov|dez|dec)(?<yyyy>(?:19|20){0,1}[0-9]{2})))";

    //https://regex101.com/r/SaKlyS/4 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    internal const string GrabFullMonthWithTwoOrFourDigitYearWithSomeCharSeparatingThemOrNot = @"(?<date>(?:(?<datewithsomecharseparating>(?<MMM>janeiro|january|fevereiro|february|março|march|abril|april|maio|may|junho|julho|agosto|august|setembro|september|outubro|october|novembro|november|dezembro|december)[-._ ]{1})|(?<datewithoutseparation>(?<MMM>janeiro|january|fevereiro|february|março|march|abril|april|maio|may|junho|julho|agosto|august|setembro|september|outubro|october|novembro|november|dezembro|december)))(?<yyyy>(?:19|20){0,1}[0-9]{2}))";

    //https://regex101.com/r/01Y8JS/3 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    internal const string GrabVersionFromFile = @"(?<version>\sv[ersionão]*[\d@]+[\w@]*|[\d@]+v[ersionão]*[\w@]*)";

    //https://regex101.com/r/BfGfIY/2 ^^^^^^^^^^^^^^^^^^^ 

    //Used at DocName:

    internal const string GrabNameAndExtension = @"(?<fullname>.+?)(\.(?<extension>[^.]*)$|$)"; //https://regex101.com/r/ThSD20/1

    internal const string GrabPartsOfName = @"([\w _<>+;.,']*)*"; //https://regex101.com/r/mduYnK/2

    internal const string GrabDelimiterWithSpaceAround = @"( - )";

    internal const string GrabFakeDelimiterWithoutAnySpaceAround = @"(?<before>[\d\w' -.]*)(?<=\w)(?<FakeDelimiter>[-˗–])(?=\w)(?<after>[\d\w -.]*)";

    // At line 3614 of DocName with NamePart v3 with CSF 2.40

    // https://dotnetfiddle.net/GXc2Vj

    /// <summary>

    /// TESTED and it is faster than the overload that accepts string pattern

    /// </summary>

    /// <param name = "rgx"></param>

    /// <param name = "part"></param>

    /// <param name = "groupName"></param>

    /// <param name = "errorMsg"></param>

    /// <returns></returns>

    internal static Result<string> ReturnResult(Regex rgx, string part, string groupName, string errorMsg)

    {

        _ = GetMatch(rgx, part, groupName, errorMsg, out var result);

        return result;

    }

​

    //Regex rgx, string part

    internal static Result<List<(string namedGroup, string value)>> ReturnResults(MatchCollection matches, string errorMsg = "No named group was captured")

    {

        //_ = GetMatch(rgx, part, groupName, errorMsg, out var result);

        //var matches = GetMatches(rgx, part);

        //Console.WriteLine($"// Matches for {namePattern}: {matches.Count}");

        var captures = GetAllMatchesWithNamedGroups(matches);

        var result = new List<(string namedGroup, string value)>();

        if (!captures.Any())

            return Result.Failure<List<(string, string)>>(errorMsg);

        //Result.Failure<(string, string)>("No named group was catured", "No named group was catured");

        foreach (var capture in captures)

        {

            foreach (var namedGroup in capture)

            {

                result.Add((namedGroup.Key, namedGroup.Value));

            }

        }

​

        return result;

    }

​

    internal static Result<List<List<(string namedGroup, string value)>>> ReturnAllResults(MatchCollection matches, string errorMsg = "No named group was captured")

    {

        //_ = GetMatch(rgx, part, groupName, errorMsg, out var result);

        //var matches = GetMatches(rgx, part);

        //Console.WriteLine($"// Matches for {namePattern}: {matches.Count}");

        var captures = GetAllMatchesWithNamedGroups(matches);

        var result = new List<(string namedGroup, string value)>();

        var results = new List<List<(string namedGroup, string value)>>();

        if (!captures.Any())

            return Result.Failure<List<List<(string, string)>>>(errorMsg);

        //Result.Failure<(string, string)>("No named group was catured", "No named group was catured");

        foreach (var capture in captures)

        {

            result.Clear();

            foreach (var namedGroup in capture)

            {

                result.Add((namedGroup.Key, namedGroup.Value));

            }

​

            results.Add(result.ToList()); // if result instead of result.ToList() ==> alias bug

        }

​

        return results;

    }

​

    internal static List<Dictionary<string, string>> GetAllMatchesWithNamedGroups(MatchCollection matches)

    {

        var counter = 0;

        var captures = new List<Dictionary<string, string>>();

        foreach (Match itemMatch in matches)

        {

            Console.WriteLine($"// \t Match {++counter}:");

            Console.WriteLine($"// \t \t Value: {itemMatch.Value}; Length: {itemMatch.Length}");

            var itemGroup = new Dictionary<string, string>();

            foreach (Group group in itemMatch.Groups)

            {

                var key = group.Name;

                if (!key.IsDigit())

                    itemGroup.Add(key, group.Value);

            }

            if (itemGroup.Any())

                captures.Add(itemGroup);

        }

​

        return captures;

    }

​

    internal static Match GetMatch(Regex rgx, string part, string groupName, string errorMsg, out Result<string> result)

    {

        //Edge case: Laudo Ortopédico afastamento laborativo por 100 dias 24082015.pdf

        //Match 1:

        //Group relationandinterval: por 100 dias

        //Group temporalrelation: por

        //Group intervalordate: 100

        //Group timeframe: dias

        //Match 2:

        //Group relationandinterval: 24082015

        //Group temporalrelation:

        //Group intervalordate: 24082015

        var match = rgx.Match(" " + part.TrimStart());

        //BUG                     ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015" 

        //Match m = Regex.Match(input, GrabNameAndExtension, RegexOptions.IgnoreCase);

        result = match.Success ? Result.Success(match.Groups[groupName].Value.Trim()) : Result.Failure<string>(errorMsg);

        return match;

    }

​

    //Used in NetFiddle

    internal static Match GetMatch(string pattern, string part) //, string groupName)

    {

        var rgx = new Regex(pattern);

        var match = rgx.Match(" " + part);

        //BUG                ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015" 

        //Match m = Regex.Match(input, GrabNameAndExtension, RegexOptions.IgnoreCase);

        return match;

    }

​

    //Used in NetFiddle

    internal static Group GetMatchMainGroup(string pattern, string part) //, string groupName)

    {

        var rgx = new Regex(pattern);

        var match = rgx.Match(part.EnsureOneSingleSpaceAtBegin());

        //BUG                ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015" 

        //Match m = Regex.Match(input, GrabNameAndExtension, RegexOptions.IgnoreCase);

        return match.Groups[0];

    }

​

    //Used in NetFiddle

    internal static Group GetMatch(string pattern, string part, string groupName)

    {

        var rgx = new Regex(pattern);

        var match = rgx.Match(part.EnsureOneSingleSpaceAtBegin());

        //BUG                ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015" 

        //Match m = Regex.Match(input, GrabNameAndExtension, RegexOptions.IgnoreCase);

        return match.Groups[groupName];

    }

​

    //Not used anywhere

    internal static MatchCollection GetMatches(string pattern, string part)

    {

        //set Regex flag to global, do not return after first match

        var rgx = new Regex(pattern, RegexOptions.Multiline);

        //var rgx = new Regex(pattern);

        var matches = rgx.Matches(part.EnsureOneSingleSpaceAtBegin());

        //BUG                    ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015"      

        return matches;

    }

​

    internal static MatchCollection GetMatches(Regex rgx, string part)

    {

        //set Regex flag to global, do not return after first match

        //var rgx = new Regex(pattern, RegexOptions.Multiline);

        //var rgx = new Regex(pattern);

        var matches = rgx.Matches(part.EnsureOneSingleSpaceAtBegin());

        //BUG                    ^^^^^ bacalhau because of GetInterval cannot get "em 2012 e 2015", only " em 2012 e 2015"      

        return matches;

    }

}

​

public static class MyExtensions

{

    const char OneBlankSpace = ' ';

    public static string EnsureOneSingleSpaceAtBegin(this string text)

    {

        return OneBlankSpace + text.TrimStart();

    }

​

    public static bool IsDigit(this string @this) => @this.All(c => c >= '0' && c <= '9');

}