public async Task <IEnumerable <string> > GetPossibleUsernamesAsync(string fullName, string knownAs, bool dashesAllowed = true, bool dotsUsed = false, CancellationToken cancellationToken = default)
{
// TODO: Also generate email addresses, based off known email address (include strip dots, all characters between '+' and '@', etc)
if (String.IsNullOrWhiteSpace(fullName))
{
throw new ArgumentNullException(nameof(fullName));
}
cancellationToken.ThrowIfCancellationRequested();
// Split all parts of the full name into parts
var allNames = fullName.ToLower().Split(' ').ToList();
// Add in nicknames/known as names if they don't already exist, if available
if (!String.IsNullOrWhiteSpace(knownAs))
{
var knownAsNames = knownAs.ToLower().Split(' ');
foreach (var knownAsName in knownAsNames)
{
if (!allNames.Contains(knownAsName))
{
allNames.Add(knownAsName);
}
}
}
var options = new ConcatenateOptions
{
DashesAllowed = dashesAllowed,
DotsUsed = dotsUsed,
};
// Walk the tree recursively, append the word alongside one with just an initial, then keep walking
var result = await ConcatenateWordsAsync(allNames, options, cancellationToken : cancellationToken);
return(result);
}
private async Task <List <string> > ConcatenateWordsAsync(List <string> remainingWords, ConcatenateOptions options, string concatTo = "", CancellationToken cancellationToken = default)
{
cancellationToken.ThrowIfCancellationRequested();
List <string> currentResults = new List <string>();
foreach (var word in remainingWords)
{
var newRemainingWords = remainingWords.ToList();
newRemainingWords.Remove(word);
// Add word, plus all permutations with the word next
currentResults.Add(concatTo + word);
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + word, cancellationToken));
if (options.DotsUsed && !String.IsNullOrWhiteSpace(concatTo))
{
// Do the same, but with a dot seperator
currentResults.Add(concatTo + "." + word);
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + "." + word, cancellationToken));
}
// If the word does not contain a dash, or dashes are allowed in usernames
if (!word.Contains("-") || options.DashesAllowed)
{
// Add initial, plus all permutations with the initial next
currentResults.Add(concatTo + word.Substring(0, 1));
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + word.Substring(0, 1), cancellationToken));
if (options.DotsUsed && !String.IsNullOrWhiteSpace(concatTo))
{
// Do the same, but with a dot seperator
currentResults.Add(concatTo + "." + word.Substring(0, 1));
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + "." + word.Substring(0, 1), cancellationToken));
}
}
// Apply additional logic for hyphenated words
if (word.Contains("-"))
{
// Get initials in context of the dash (e.g. "sj" for "Smith-Johnson")
var splitDashWord = word.Split('-').ToList();
string dashInitials = "";
foreach (var dashWord in splitDashWord)
{
dashInitials = dashInitials + dashWord.Substring(0, 1);
}
// Add word without the dash, plus all permutations with the word next
currentResults.Add(concatTo + word.Trim('-'));
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + word.Trim('-'), cancellationToken));
// Add hyphenated initials, plus all permutations with the hyphenated initials next
currentResults.Add(concatTo + dashInitials);
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + dashInitials, cancellationToken));
if (options.DotsUsed && !String.IsNullOrWhiteSpace(concatTo))
{
// Do the same, but with a dot seperator...
// Add word without the dash, plus all permutations with the word next
currentResults.Add(concatTo + "." + word.Trim('-'));
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + "." + word.Trim('-'), cancellationToken));
// Add hyphenated initials, plus all permutations with the hyphenated initials next
currentResults.Add(concatTo + "." + dashInitials);
currentResults.AddRange(await ConcatenateWordsAsync(newRemainingWords, options, concatTo + "." + dashInitials, cancellationToken));
}
}
}
return(currentResults.Distinct().ToList());
}
