/// <summary>
/// Gets the list of TLD rules from the cache
/// </summary>
/// <returns></returns>
private IDictionary <TLDRule.RuleType, IDictionary <string, TLDRule> > GetTLDRules()
{
var results = new Dictionary <TLDRule.RuleType, IDictionary <string, TLDRule> >();
var rules = Enum.GetValues(typeof(TLDRule.RuleType)).Cast <TLDRule.RuleType>();
foreach (var rule in rules)
{
results[rule] = new Dictionary <string, TLDRule>(StringComparer.InvariantCultureIgnoreCase);
}
var ruleStrings = ReadRulesData();
// Strip out any lines that are:
// a.) A comment
// b.) Blank
foreach (var ruleString in ruleStrings.Where(ruleString => !ruleString.StartsWith("//", StringComparison.InvariantCultureIgnoreCase) && ruleString.Trim().Length != 0))
{
var result = new TLDRule(ruleString);
results[result.Type][result.Name] = result;
}
// Return our results:
Debug.WriteLine(string.Format("Loaded {0} rules into cache.", results.Values.Sum(r => r.Values.Count)));
return(results);
}
/// <summary>
/// Constructs a DomainName object from its 3 parts
/// </summary>
/// <param name="TLD">The top-level domain</param>
/// <param name="SLD">The second-level domain</param>
/// <param name="SubDomain">The subdomain portion</param>
/// <param name="TLDRule">The rule used to parse the domain</param>
private DomainName(string TLD, string SLD, string SubDomain, TLDRule TLDRule)
{
this._tld = TLD;
this._domain = SLD;
this._subDomain = SubDomain;
this._tldRule = TLDRule;
}
/// <summary>
/// Converts the string representation of a domain to its DomainName equivalent. A return value
/// indicates whether the operation succeeded.
/// </summary>
/// <param name="domainString"></param>
/// <param name="result"></param>
/// <returns></returns>
public static bool TryParse(string domainString, out DomainName result)
{
bool retval = false;
// Our temporary domain parts:
string _tld = string.Empty;
string _sld = string.Empty;
string _subdomain = string.Empty;
TLDRule _tldrule = null;
result = null;
try
{
// Try parsing the domain name ... this might throw formatting exceptions
ParseDomainName(domainString, out _tld, out _sld, out _subdomain, out _tldrule);
// Construct a new DomainName object and return it
result = new DomainName(_tld, _sld, _subdomain, _tldrule);
// Return 'true'
retval = true;
}
catch
{
// Looks like something bad happened -- return 'false'
retval = false;
}
return(retval);
}
/// <summary>
/// Finds matching rule for a domain. If no rule is found,
/// returns a null TLDRule object
/// </summary>
/// <param name="domainString"></param>
/// <returns></returns>
private static TLDRule FindMatchingTLDRule(string domainString)
{
// Split our domain into parts (based on the '.')
// ...Put these parts in a list
// ...Make sure these parts are in reverse order (we'll be checking rules from the right-most pat of the domain)
List <string> lstDomainParts = domainString.Split('.').ToList <string>();
lstDomainParts.Reverse();
// Begin building our partial domain to check rules with:
string checkAgainst = string.Empty;
// Our 'matches' collection:
List <TLDRule> ruleMatches = new List <TLDRule>();
foreach (string domainPart in lstDomainParts)
{
// Add on our next domain part:
checkAgainst = string.Format("{0}.{1}", domainPart, checkAgainst);
// If we end in a period, strip it off:
if (checkAgainst.EndsWith("."))
{
checkAgainst = checkAgainst.Substring(0, checkAgainst.Length - 1);
}
var rules = Enum.GetValues(typeof(TLDRule.RuleType)).Cast <TLDRule.RuleType>();
var ruleList = TLDRulesCache.Instance.GetTLDRuleList();
foreach (var rule in rules)
{
// Try to match rule:
TLDRule result;
if (ruleList[rule].TryGetValue(checkAgainst, out result))
{
ruleMatches.Add(result);
}
Debug.WriteLine(string.Format("Domain part {0} matched {1} {2} rules", checkAgainst, result == null ? 0 : 1, rule));
}
}
// Sort our matches list (longest rule wins, according to :
var results = from match in ruleMatches
orderby match.Name.Length descending
select match;
// Take the top result (our primary match):
TLDRule primaryMatch = results.Take(1).SingleOrDefault();
if (primaryMatch != null)
{
Debug.WriteLine(
string.Format("Looks like our match is: {0}, which is a(n) {1} rule.", primaryMatch.Name, primaryMatch.Type)
);
}
else
{
Debug.WriteLine(
string.Format("No rules matched domain: {0}", domainString)
);
}
return(primaryMatch);
}
/// <summary>
/// Converts the string representation of a domain to it's 3 distinct components:
/// Top Level Domain (TLD), Second Level Domain (SLD), and subdomain information
/// </summary>
/// <param name="domainString">The domain to parse</param>
/// <param name="TLD"></param>
/// <param name="SLD"></param>
/// <param name="SubDomain"></param>
/// <param name="MatchingRule"></param>
private static void ParseDomainName(string domainString, out string TLD, out string SLD, out string SubDomain, out TLDRule MatchingRule)
{
TLD = string.Empty;
SLD = string.Empty;
SubDomain = string.Empty;
MatchingRule = null;
// If the fqdn is empty, we have a problem already
if (domainString.Trim() == string.Empty)
{
throw new ArgumentException("The domain cannot be blank");
}
// Next, find the matching rule:
MatchingRule = FindMatchingTLDRule(domainString);
// At this point, no rules match, we have a problem
if (MatchingRule == null)
{
throw new FormatException("The domain does not have a recognized TLD");
}
// Based on the tld rule found, get the domain (and possibly the subdomain)
string tempSudomainAndDomain = string.Empty;
int tldIndex = 0;
// First, determine what type of rule we have, and set the TLD accordingly
switch (MatchingRule.Type)
{
case TLDRule.RuleType.Normal:
tldIndex = domainString.LastIndexOf("." + MatchingRule.Name, StringComparison.InvariantCultureIgnoreCase);
tempSudomainAndDomain = domainString.Substring(0, tldIndex);
TLD = domainString.Substring(tldIndex + 1);
break;
case TLDRule.RuleType.Wildcard:
// This finds the last portion of the TLD...
tldIndex = domainString.LastIndexOf("." + MatchingRule.Name, StringComparison.InvariantCultureIgnoreCase);
tempSudomainAndDomain = domainString.Substring(0, tldIndex);
// But we need to find the wildcard portion of it:
tldIndex = tempSudomainAndDomain.LastIndexOf(".", StringComparison.InvariantCultureIgnoreCase);
tempSudomainAndDomain = domainString.Substring(0, tldIndex);
TLD = domainString.Substring(tldIndex + 1);
break;
case TLDRule.RuleType.Exception:
tldIndex = domainString.LastIndexOf(".", StringComparison.InvariantCultureIgnoreCase);
tempSudomainAndDomain = domainString.Substring(0, tldIndex);
TLD = domainString.Substring(tldIndex + 1);
break;
}
// See if we have a subdomain:
List <string> lstRemainingParts = new List <string>(tempSudomainAndDomain.Split('.'));
// If we have 0 parts left, there is just a tld and no domain or subdomain
// If we have 1 part, it's the domain, and there is no subdomain
// If we have 2+ parts, the last part is the domain, the other parts (combined) are the subdomain
if (lstRemainingParts.Count > 0)
{
// Set the domain:
SLD = lstRemainingParts[lstRemainingParts.Count - 1];
// Set the subdomain, if there is one to set:
if (lstRemainingParts.Count > 1)
{
// We strip off the trailing period, too
SubDomain = tempSudomainAndDomain.Substring(0, tempSudomainAndDomain.Length - SLD.Length - 1);
}
}
}
