// If this returns null, it failed.
public SplitEmailModel SplitEmail(string email = null)
{
if (String.IsNullOrEmpty(email))
{
return(null);
}
email = !String.IsNullOrEmpty(email) ? email.Trim() : null; // trim() not exist in old IE!
string[] parts = new string[] { };
parts = email.Split('@');
if (parts.Length < 2)
{
return(null);
}
for (var i = 0; i < parts.Length; i++)
{
if (parts[i] == "")
{
return(null);
}
}
string username = parts.First();
string domain = parts.Last();
string[] domainParts = domain.Split('.');
string sld = "";
string tld = "";
if (domainParts.Length == 0)
{
// The address does not have a top-level domain
return(null);
}
else if (domainParts.Length == 1)
{
// The address has only a top-level domain (valid under RFC)
tld = domainParts[0];
}
else
{
// The address has a domain and a top-level domain
sld = domainParts[0];
for (var j = 1; j < domainParts.Length; j++)
{
tld += domainParts[j] + '.';
}
tld = tld.Substring(0, tld.Length - 1);
}
SplitEmailModel result = new SplitEmailModel {
TopLevelDomain = tld, SecondLevelDomain = sld, Username = username, Domain = domain, Address = String.Join("@", parts)
};
return(result);
}
public SplitEmailModel Suggest(string email = null, string[] domains = null, string[] secondLevelDomains = null, string[] topLevelDomains = null, Func <string> distanceFunction = null)
{
email = email.ToLower();
SplitEmailModel emailParts = SplitEmail(email);
if (emailParts == null)
{
return(null);
}
if (secondLevelDomains != null && topLevelDomains != null)
{
// If the email is a valid 2nd-level + top-level, do not suggest anything.
if (secondLevelDomains.Contains(emailParts.SecondLevelDomain) && topLevelDomains.Contains(emailParts.TopLevelDomain))
{
return(null);
}
}
string closestDomain = FindClosestDomain(emailParts.Domain, domains, DomainThreshold);
if (!String.IsNullOrEmpty(closestDomain))
{
if (closestDomain == emailParts.Domain)
{
// The email address exactly matches one of the supplied domains; do not return a suggestion.
return(null);
}
else
{
// The email address closely matches one of the supplied domains; return a suggestion
SplitEmailModel result = new SplitEmailModel {
Username = emailParts.Username, Domain = closestDomain, Address = emailParts.Username + "@" + closestDomain
};
return(result);
}
}
// The email address does not closely match one of the supplied domains
var closestSecondLevelDomain = FindClosestDomain(emailParts.SecondLevelDomain, secondLevelDomains, SecondLevelThreshold);
var closestTopLevelDomain = FindClosestDomain(emailParts.TopLevelDomain, topLevelDomains, TopLevelThreshold);
if (!String.IsNullOrEmpty(emailParts.Domain))
{
closestDomain = emailParts.Domain;
var rtrn = false;
if (!String.IsNullOrEmpty(closestSecondLevelDomain) && closestSecondLevelDomain != emailParts.SecondLevelDomain)
{
// The email address may have a mispelled second-level domain; return a suggestion
closestDomain = closestDomain.Replace(emailParts.SecondLevelDomain, closestSecondLevelDomain);
//closestDomain = closestDomain.Replace(new RegExp(emailParts.topLevelDomain + "$"), closestTopLevelDomain);
rtrn = true;
}
if (!String.IsNullOrEmpty(closestTopLevelDomain) && closestTopLevelDomain != emailParts.TopLevelDomain && emailParts.SecondLevelDomain != "")
{
// The email address may have a mispelled top-level domain; return a suggestion
closestDomain = closestDomain.Replace(emailParts.TopLevelDomain, closestTopLevelDomain);
rtrn = true;
}
if (rtrn)
{
var result = new SplitEmailModel {
Username = emailParts.Address, Domain = closestDomain, Address = emailParts.Username + "@" + closestDomain
};
return(result);
}
}
/* The email address exactly matches one of the supplied domains, does not closely
* match any domain and does not appear to simply have a mispelled top-level domain,
* or is an invalid email address; do not return a suggestion.
*/
return(null);
}
