Moved username formatting to INI file

Rather than having the username limitations hard coded, I have moved it
into the ini file. I have added some examples to the code and also to
the ini.

This is only and example and can be expanded on by others.

servatrice/servatrice.ini.example

@@ -54,6 +54,29 @@ password=123456
 ; Accept only registered users? default is 0 (accept unregistered users)
 regonly=0
 
+[users]
+
+; The minimum length a username can be
+minnamelength=6
+
+; The maximum length a username can be
+maxnamelength=12
+
+; If a username should be allowed to contain lowercase chars [a-z]
+allowlowercase=true
+
+; If a username should be allowed to conatain uppercase chars [A-Z]
+allowuppercase=true
+
+; If a username should be allowed to contain numbers [0-9]
+allownumerics=true
+
+; Define punctuation allowed in usernames
+allowedpunctuation=_.-
+
+; If a username can begin with punctuation defined in allowedpunctuation
+allowpunctuationprefix=false
+
 [registration]
 
 ; Servatrice can process registration requests to add new users on the fly.

servatrice/src/servatrice_database_interface.cpp

@@ -120,7 +120,27 @@ bool Servatrice_DatabaseInterface::execSqlQuery(QSqlQuery *query)
 
 bool Servatrice_DatabaseInterface::usernameIsValid(const QString &user)
 {
-    static QRegExp re = QRegExp("[a-zA-Z0-9_\\.-]+");
+    int maxNameLength = settingsCache->value("users/maxnamelength").toInt();
+    int minNameLength = settingsCache->value("users/minnamelength").toInt();
+    if (user.length() < minNameLength || user.length() > maxNameLength)
+        return false;
+
+    bool allowPunctuationPrefix = settingsCache->value("users/allowpunctuationprefix").toBool();
+    QString allowedPunctuation = settingsCache->value("users/allowedpunctuation").toString();
+    if (!allowPunctuationPrefix && allowedPunctuation.contains(user.at(0)))
+        return false;
+
+    QString regEx("[");
+    if (settingsCache->value("users/allowlowercase").toBool())
+        regEx.append("a-z");
+    if (settingsCache->value("users/allowuppercase").toBool())
+        regEx.append("A-Z");
+    if(settingsCache->value("users/allownumerics").toBool())
+        regEx.append("0-9");
+    regEx.append(allowedPunctuation);
+    regEx.append("]+");
+
+    static QRegExp re = QRegExp(regEx);
     return re.exactMatch(user);
 }