Imports System.IO
Imports System.Security.Cryptography
Imports System.Text
Imports System.Text.RegularExpressions

Public Class StringEx
    ''' <summary>
    ''' Creates a "slug" from text that can be used as part of a valid URL.
    ''' Invalid characters are converted to hyphens. Punctuation that Is
    ''' perfect valid in a URL Is also converted to hyphens to keep the
    ''' result mostly text. Steps are taken to prevent leading, trailing,
    ''' And consecutive hyphens.
    ''' </summary>
    ''' <param name="s">The string to convert</param>
    Public Shared Function ConvertTextToSlug(s As String) As String
        Dim oBuilder As New StringBuilder()
        Dim oWasHyphen As Boolean = True

        For Each oChar As Char In s

            If Char.IsLetterOrDigit(oChar) Then
                oBuilder.Append(Char.ToLower(oChar))
                oWasHyphen = False

            ElseIf oChar = "_"c Or oChar = "-"c Then
                oBuilder.Append(oChar)
                oWasHyphen = True

            ElseIf Char.IsWhiteSpace(oChar) AndAlso Not oWasHyphen Then
                oBuilder.Append("_"c)
                oWasHyphen = True
            End If
        Next

        If oWasHyphen AndAlso oBuilder.Length > 0 Then oBuilder.Length -= 1
        Return oBuilder.ToString()
    End Function

    ''' <summary>
    ''' Removes Invalid characters from a string, suitable for file and path names
    ''' 
    ''' Removed characters are:
    ''' 
    ''' * Illegal File-characters
    ''' * Illegal Path-characters
    ''' * Unicode characters that classify as Emoji
    ''' * All characters above codepoint U+10000
    ''' 
    ''' See: 
    ''' https://stackoverflow.com/questions/46905176/detecting-all-emojis
    ''' https://stackoverflow.com/questions/28023682/how-do-i-remove-emoji-characters-from-a-string
    ''' </summary>
    ''' <returns></returns>
    Public Shared Function RemoveInvalidCharacters(pString As String) As String
        Dim oResult = pString

        Try
            ' Remove all Unicode above Codepoint U+10000
            oResult = Regex.Replace(oResult, InvalidChars.UnicodeSurrogates, String.Empty)

            ' Remove all Emojis (Version 13)
            oResult = Regex.Replace(oResult, InvalidChars.Emojis, String.Empty)

            ' Remove Invalid filename characters
            oResult = Regex.Replace(oResult, InvalidChars.Filenames, String.Empty)

            ' Remove Invalid filename characters
            oResult = Regex.Replace(oResult, InvalidChars.Paths, String.Empty)

            ' Remove Uneccessary characters
            oResult = Regex.Replace(oResult, "\s{2,}", " ")
            oResult = Regex.Replace(oResult, "\.{2,}", ".")

            ' Remove excess space chars
            oResult = oResult.Trim()

            Return oResult
        Catch ex As Exception
            Return oResult
        End Try
    End Function

    ''' <summary>
    ''' Generates a random short (8 characters) guid
    ''' </summary>
    ''' <returns>The generated guid as a String</returns>
    Public Shared Function GetShortGUID() As String
        Return Guid.NewGuid().ToString().GetHashCode().ToString("x")
    End Function

    ''' <summary>
    ''' Checks if string contains invalid characters
    ''' </summary>
    ''' <param name="pString"></param>
    ''' <returns></returns>
    Public Shared Function TestContainsInvalidCharacters(pString As String) As Boolean
        Return Not pString.Equals(RemoveInvalidCharacters(pString))
    End Function

    ''' <summary>
    ''' Creates a hash using the SHA256 algorithm and returns it
    ''' </summary>
    ''' <param name="pStringToCheck">Any string</param>
    ''' <returns></returns>
    Public Shared Function GetChecksum(pStringToCheck As String) As String
        Dim oBytes() As Byte = Encoding.UTF8.GetBytes(pStringToCheck)
        Dim oChecksum() As Byte = SHA256.Create.ComputeHash(oBytes)
        Return BaseUtils.FormatHash(oChecksum)
    End Function

    Public Shared Function GetHash(pStringToCheck As String) As String
        Return GetChecksum(pStringToCheck)
    End Function

    Public Shared Function GetShortHash(pStringToCheck As String) As String
        Return GetChecksum(pStringToCheck).Substring(0, 32)
    End Function

    Public Shared Function GetDateString() As String
        Return $"{Now:yyyy\\MM\\dd}"
    End Function

    Public Shared Function GetDateString(pDate As Date) As String
        Return $"{pDate:yyyy\\MM\\dd}"
    End Function

    Public Shared Function GetDateTimeString() As String
        Return $"{Now:yyyy-MM-dd_hh-mm-ffff}"
    End Function

    Public Shared Function GetDateTimeString(pDate As Date) As String
        Return $"{pDate:yyyy-MM-dd_hh-mm-ffff}"
    End Function

    Friend Class InvalidChars
        Public Shared Filenames As String = Regex.Escape(New String(IO.Path.GetInvalidFileNameChars()))
        Public Shared Paths As String = Regex.Escape(New String(IO.Path.GetInvalidPathChars()))
        Public Shared UnicodeSurrogates = "\p{Cs}"
        Public Shared Emojis = "\uD83D(?:\uDC68(?:\uD83C(?:[\uDFFB-\uDFFF]\u200D(?:\u2764\uFE0F?\u200D\uD83D(?:\uDC8B\u200D\uD83D)?\uDC68\uD83C[\uDFFB-\uDFFF]|\uD83E(?:\uDD1D\u200D\uD83D\uDC68\uD83C[\uDFFB-\uDFFF]|[\uDDAF-\uDDB3\uDDBC\uDDBD])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83D[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92])|[\uDFFB-\uDFFF])|\u200D(?:\u2764\uFE0F?\u200D\uD83D(?:\uDC8B\u200D\uD83D)?\uDC68|\uD83D(?:(?:[\uDC68\uDC69]\u200D\uD83D)?(?:\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?)|[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83E[\uDDAF-\uDDB3\uDDBC\uDDBD]))?|\uDC69(?:\uD83C(?:[\uDFFB-\uDFFF]\u200D(?:\u2764\uFE0F?\u200D\uD83D(?:\uDC8B\u200D\uD83D[\uDC68\uDC69]|[\uDC68\uDC69])\uD83C[\uDFFB-\uDFFF]|\uD83E(?:\uDD1D\u200D\uD83D[\uDC68\uDC69]\uD83C[\uDFFB-\uDFFF]|[\uDDAF-\uDDB3\uDDBC\uDDBD])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83D[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92])|[\uDFFB-\uDFFF])|\u200D(?:\u2764\uFE0F?\u200D\uD83D(?:\uDC8B\u200D\uD83D[\uDC68\uDC69]|[\uDC68\uDC69])|\uD83D(?:(?:\uDC69\u200D\uD83D)?(?:\uDC66(?:\u200D\uD83D\uDC66)?|\uDC67(?:\u200D\uD83D[\uDC66\uDC67])?)|[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83E[\uDDAF-\uDDB3\uDDBC\uDDBD]))?|(?:\uDD75(?:\uD83C[\uDFFB-\uDFFF]|\uFE0F)?|\uDC6F)(?:\u200D[\u2640\u2642]\uFE0F?)?|[\uDC6E\uDC70\uDC71\uDC73\uDC77\uDC81\uDC82\uDC86\uDC87\uDE45-\uDE47\uDE4B\uDE4D\uDE4E\uDEA3\uDEB4-\uDEB6](?:\uD83C[\uDFFB-\uDFFF](?:\u200D[\u2640\u2642]\uFE0F?)?|\u200D[\u2640\u2642]\uFE0F?)?|\uDC41(?:\uFE0F(?:\u200D\uD83D\uDDE8\uFE0F?)?|\u200D\uD83D\uDDE8\uFE0F?)?|\uDE36(?:\u200D\uD83C\uDF2B\uFE0F?)?|\uDC15(?:\u200D\uD83E\uDDBA)?|\uDC3B(?:\u200D\u2744\uFE0F?)?|\uDE2E(?:\u200D\uD83D\uDCA8)?|\uDE35(?:\u200D\uD83D\uDCAB)?|[\uDC42\uDC43\uDC46-\uDC50\uDC66\uDC67\uDC6B-\uDC6D\uDC72\uDC74-\uDC76\uDC78\uDC7C\uDC83\uDC85\uDC8F\uDC91\uDCAA\uDD7A\uDD95\uDD96\uDE4C\uDE4F\uDEC0\uDECC](?:\uD83C[\uDFFB-\uDFFF])?|[\uDD74\uDD90]\uD83C[\uDFFB-\uDFFF]|\uDC08(?:\u200D\u2B1B)?|[\uDC3F\uDCFD\uDD49\uDD4A\uDD6F\uDD70\uDD73\uDD74\uDD76-\uDD79\uDD87\uDD8A-\uDD8D\uDD90\uDDA5\uDDA8\uDDB1\uDDB2\uDDBC\uDDC2-\uDDC4\uDDD1-\uDDD3\uDDDC-\uDDDE\uDDE1\uDDE3\uDDE8\uDDEF\uDDF3\uDDFA\uDECB\uDECD-\uDECF\uDEE0-\uDEE5\uDEE9\uDEF0\uDEF3]\uFE0F?|[\uDC00-\uDC07\uDC09-\uDC14\uDC16-\uDC3A\uDC3C-\uDC3E\uDC40\uDC44\uDC45\uDC51-\uDC65\uDC6A\uDC79-\uDC7B\uDC7D-\uDC80\uDC84\uDC88-\uDC8E\uDC90\uDC92-\uDCA9\uDCAB-\uDCFC\uDCFF-\uDD3D\uDD4B-\uDD4E\uDD50-\uDD67\uDDA4\uDDFB-\uDE2D\uDE2F-\uDE34\uDE37-\uDE44\uDE48-\uDE4A\uDE80-\uDEA2\uDEA4-\uDEB3\uDEB7-\uDEBF\uDEC1-\uDEC5\uDED0-\uDED2\uDED5-\uDED7\uDEEB\uDEEC\uDEF4-\uDEFC\uDFE0-\uDFEB])|\uD83E(?:\uDDD1(?:\uD83C(?:[\uDFFB-\uDFFF]\u200D(?:\u2764\uFE0F?\u200D(?:\uD83D\uDC8B\u200D)?\uD83E\uDDD1\uD83C[\uDFFB-\uDFFF]|\uD83E(?:\uDD1D\u200D\uD83E\uDDD1\uD83C[\uDFFB-\uDFFF]|[\uDDAF-\uDDB3\uDDBC\uDDBD])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF84\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83D[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92])|[\uDFFB-\uDFFF])|\u200D(?:\uD83E(?:\uDD1D\u200D\uD83E\uDDD1|[\uDDAF-\uDDB3\uDDBC\uDDBD])|[\u2695\u2696\u2708]\uFE0F?|\uD83C[\uDF3E\uDF73\uDF7C\uDF84\uDF93\uDFA4\uDFA8\uDFEB\uDFED]|\uD83D[\uDCBB\uDCBC\uDD27\uDD2C\uDE80\uDE92]))?|[\uDD26\uDD35\uDD37-\uDD39\uDD3D\uDD3E\uDDB8\uDDB9\uDDCD-\uDDCF\uDDD4\uDDD6-\uDDDD](?:\uD83C[\uDFFB-\uDFFF](?:\u200D[\u2640\u2642]\uFE0F?)?|\u200D[\u2640\u2642]\uFE0F?)?|[\uDD3C\uDDDE\uDDDF](?:\u200D[\u2640\u2642]\uFE0F?)?|[\uDD0C\uDD0F\uDD18-\uDD1C\uDD1E\uDD1F\uDD30-\uDD34\uDD36\uDD77\uDDB5\uDDB6\uDDBB\uDDD2\uDDD3\uDDD5](?:\uD83C[\uDFFB-\uDFFF])?|[\uDD0D\uDD0E\uDD10-\uDD17\uDD1D\uDD20-\uDD25\uDD27-\uDD2F\uDD3A\uDD3F-\uDD45\uDD47-\uDD76\uDD78\uDD7A-\uDDB4\uDDB7\uDDBA\uDDBC-\uDDCB\uDDD0\uDDE0-\uDDFF\uDE70-\uDE74\uDE78-\uDE7A\uDE80-\uDE86\uDE90-\uDEA8\uDEB0-\uDEB6\uDEC0-\uDEC2\uDED0-\uDED6])|\uD83C(?:\uDFF4(?:\uDB40\uDC67\uDB40\uDC62\uDB40(?:\uDC65\uDB40\uDC6E\uDB40\uDC67|\uDC73\uDB40\uDC63\uDB40\uDC74|\uDC77\uDB40\uDC6C\uDB40\uDC73)\uDB40\uDC7F|\u200D\u2620\uFE0F?)?|[\uDFC3\uDFC4\uDFCA](?:\uD83C[\uDFFB-\uDFFF](?:\u200D[\u2640\u2642]\uFE0F?)?|\u200D[\u2640\u2642]\uFE0F?)?|[\uDFCB\uDFCC](?:\uD83C[\uDFFB-\uDFFF]|\uFE0F)(?:\u200D[\u2640\u2642]\uFE0F?)?|\uDFF3(?:\uFE0F(?:\u200D(?:\u26A7\uFE0F?|\uD83C\uDF08))?|\u200D(?:\u26A7\uFE0F?|\uD83C\uDF08))?|(?:[\uDFCB\uDFCC]\u200D[\u2640\u2642]|[\uDD70\uDD71\uDD7E\uDD7F\uDE02\uDE37\uDF21\uDF24-\uDF2C\uDF36\uDF7D\uDF96\uDF97\uDF99-\uDF9B\uDF9E\uDF9F\uDFCD\uDFCE\uDFD4-\uDFDF\uDFF5\uDFF7])\uFE0F?|[\uDF85\uDFC2\uDFC7](?:\uD83C[\uDFFB-\uDFFF])?|\uDDE6\uD83C[\uDDE8-\uDDEC\uDDEE\uDDF1\uDDF2\uDDF4\uDDF6-\uDDFA\uDDFC\uDDFD\uDDFF]|\uDDE7\uD83C[\uDDE6\uDDE7\uDDE9-\uDDEF\uDDF1-\uDDF4\uDDF6-\uDDF9\uDDFB\uDDFC\uDDFE\uDDFF]|\uDDE8\uD83C[\uDDE6\uDDE8\uDDE9\uDDEB-\uDDEE\uDDF0-\uDDF5\uDDF7\uDDFA-\uDDFF]|\uDDE9\uD83C[\uDDEA\uDDEC\uDDEF\uDDF0\uDDF2\uDDF4\uDDFF]|\uDDEA\uD83C[\uDDE6\uDDE8\uDDEA\uDDEC\uDDED\uDDF7-\uDDFA]|\uDDEB\uD83C[\uDDEE-\uDDF0\uDDF2\uDDF4\uDDF7]|\uDDEC\uD83C[\uDDE6\uDDE7\uDDE9-\uDDEE\uDDF1-\uDDF3\uDDF5-\uDDFA\uDDFC\uDDFE]|\uDDED\uD83C[\uDDF0\uDDF2\uDDF3\uDDF7\uDDF9\uDDFA]|\uDDEE\uD83C[\uDDE8-\uDDEA\uDDF1-\uDDF4\uDDF6-\uDDF9]|\uDDEF\uD83C[\uDDEA\uDDF2\uDDF4\uDDF5]|\uDDF0\uD83C[\uDDEA\uDDEC-\uDDEE\uDDF2\uDDF3\uDDF5\uDDF7\uDDFC\uDDFE\uDDFF]|\uDDF1\uD83C[\uDDE6-\uDDE8\uDDEE\uDDF0\uDDF7-\uDDFB\uDDFE]|\uDDF2\uD83C[\uDDE6\uDDE8-\uDDED\uDDF0-\uDDFF]|\uDDF3\uD83C[\uDDE6\uDDE8\uDDEA-\uDDEC\uDDEE\uDDF1\uDDF4\uDDF5\uDDF7\uDDFA\uDDFF]|\uDDF4\uD83C\uDDF2|\uDDF5\uD83C[\uDDE6\uDDEA-\uDDED\uDDF0-\uDDF3\uDDF7-\uDDF9\uDDFC\uDDFE]|\uDDF6\uD83C\uDDE6|\uDDF7\uD83C[\uDDEA\uDDF4\uDDF8\uDDFA\uDDFC]|\uDDF8\uD83C[\uDDE6-\uDDEA\uDDEC-\uDDF4\uDDF7-\uDDF9\uDDFB\uDDFD-\uDDFF]|\uDDF9\uD83C[\uDDE6\uDDE8\uDDE9\uDDEB-\uDDED\uDDEF-\uDDF4\uDDF7\uDDF9\uDDFB\uDDFC\uDDFF]|\uDDFA\uD83C[\uDDE6\uDDEC\uDDF2\uDDF3\uDDF8\uDDFE\uDDFF]|\uDDFB\uD83C[\uDDE6\uDDE8\uDDEA\uDDEC\uDDEE\uDDF3\uDDFA]|\uDDFC\uD83C[\uDDEB\uDDF8]|\uDDFD\uD83C\uDDF0|\uDDFE\uD83C[\uDDEA\uDDF9]|\uDDFF\uD83C[\uDDE6\uDDF2\uDDFC]|[\uDC04\uDCCF\uDD8E\uDD91-\uDD9A\uDE01\uDE1A\uDE2F\uDE32-\uDE36\uDE38-\uDE3A\uDE50\uDE51\uDF00-\uDF20\uDF2D-\uDF35\uDF37-\uDF7C\uDF7E-\uDF84\uDF86-\uDF93\uDFA0-\uDFC1\uDFC5\uDFC6\uDFC8\uDFC9\uDFCB\uDFCC\uDFCF-\uDFD3\uDFE0-\uDFF0\uDFF8-\uDFFF])|\u26F9(?:(?:\uD83C[\uDFFB-\uDFFF]|\uFE0F)(?:\u200D[\u2640\u2642]\uFE0F?)?|\u200D[\u2640\u2642]\uFE0F?)?|\u2764(?:\uFE0F(?:\u200D(?:\uD83D\uDD25|\uD83E\uDE79))?|\u200D(?:\uD83D\uDD25|\uD83E\uDE79))?|[\#\*0-9]\uFE0F?\u20E3|[\u261D\u270C\u270D]\uD83C[\uDFFB-\uDFFF]|[\u270A\u270B](?:\uD83C[\uDFFB-\uDFFF])?|[\u00A9\u00AE\u203C\u2049\u2122\u2139\u2194-\u2199\u21A9\u21AA\u2328\u23CF\u23ED-\u23EF\u23F1\u23F2\u23F8-\u23FA\u24C2\u25AA\u25AB\u25B6\u25C0\u25FB\u25FC\u2600-\u2604\u260E\u2611\u2618\u261D\u2620\u2622\u2623\u2626\u262A\u262E\u262F\u2638-\u263A\u2640\u2642\u265F\u2660\u2663\u2665\u2666\u2668\u267B\u267E\u2692\u2694-\u2697\u2699\u269B\u269C\u26A0\u26A7\u26B0\u26B1\u26C8\u26CF\u26D1\u26D3\u26E9\u26F0\u26F1\u26F4\u26F7\u26F8\u2702\u2708\u2709\u270C\u270D\u270F\u2712\u2714\u2716\u271D\u2721\u2733\u2734\u2744\u2747\u2763\u27A1\u2934\u2935\u2B05-\u2B07\u3030\u303D\u3297\u3299]\uFE0F?|[\u231A\u231B\u23E9-\u23EC\u23F0\u23F3\u25FD\u25FE\u2614\u2615\u2648-\u2653\u267F\u2693\u26A1\u26AA\u26AB\u26BD\u26BE\u26C4\u26C5\u26CE\u26D4\u26EA\u26F2\u26F3\u26F5\u26FA\u26FD\u2705\u2728\u274C\u274E\u2753-\u2755\u2757\u2795-\u2797\u27B0\u27BF\u2B1B\u2B1C\u2B50\u2B55]"
    End Class
End Class