Add the accountnicks metadata as a replacement for user mode +r.

This isn't used much currently but in the future will allow doing
a lot of behaviour which is currently implemented in services in
the IRCd instead e.g. killing ghost clients, nickname enforcement.

include/modules/account.h

@@ -26,6 +26,9 @@ namespace Account
 	class API;
 	class APIBase;
 	class EventListener;
+
+	/** Encapsulates a list of nicknames associated with an account. */
+	typedef insp::flat_set<std::string, irc::insensitive_swo> NickList;
 }
 
 /** Defines the interface for the account API. */
@@ -49,6 +52,18 @@ public:
 	 * @return If the user is logged in to an account then the account name; otherwise, nullptr.
 	 */
 	virtual std::string* GetAccountName(const User* user) const = 0;
+
+	/** Retrieves the account nicks of the specified user.
+	 * @param user The user to retrieve the account nicks of.
+	 * @return If the user is logged in to an account then the account nicks; otherwise, nullptr.
+	 */
+	virtual NickList* GetAccountNicks(const User* user) const = 0;
+
+	/** Determines whether a user is identified to their nickname.
+	* @param user The user to check the identification status of.
+	* @return If the user is identified to their nickname then true; otherwise, false.
+	*/
+	virtual bool IsIdentifiedToNick(const User* user) = 0;
 };
 
 /** Allows modules to access information regarding user accounts. */

src/modules/m_services_account.cpp

@@ -130,18 +130,63 @@ public:
 	}
 };
 
+
+class AccountNicksExtItem final
+	: public SimpleExtItem<Account::NickList>
+{
+public:
+	AccountNicksExtItem(Module* mod)
+		: SimpleExtItem<Account::NickList>(mod, "accountnicks", ExtensionType::USER, true)
+	{
+	}
+
+	void FromInternal(Extensible* container, const std::string& value) noexcept override
+	{
+		if (container->extype != this->extype)
+			return;
+
+		auto list = new Account::NickList();
+		irc::spacesepstream nickstream(value);
+		for (std::string nick; nickstream.GetToken(nick); )
+			list->insert(nick);
+
+		if (list->empty())
+		{
+			// The remote sent an empty list of nicknames for some reason.
+			delete list;
+			Unset(container);
+		}
+		else
+		{
+			// The remote sent a non-zero list of nicks; set it.
+			Set(container, list);
+		}
+	}
+
+	std::string ToInternal(const Extensible* container, void* item) const noexcept override
+	{
+		auto list = static_cast<Account::NickList*>(item);
+		return stdalgo::string::join(*list);
+	}
+};
+
+
 class AccountAPIImpl final
 	: public Account::APIBase
 {
 private:
 	AccountExtItemImpl accountext;
 	StringExtItem accountidext;
+	AccountNicksExtItem accountnicksext;
+	UserModeReference identifiedmode;
 
 public:
 	AccountAPIImpl(Module* mod)
 		: Account::APIBase(mod)
 		, accountext(mod)
 		, accountidext(mod, "accountid", ExtensionType::USER, true)
+		, accountnicksext(mod)
+		, identifiedmode(mod, "u_registered")
 	{
 	}
 
@@ -154,6 +199,21 @@ public:
 	{
 		return accountext.Get(user);
 	}
+
+	Account::NickList* GetAccountNicks(const User* user) const override
+	{
+		return accountnicksext.Get(user);
+	}
+
+	bool IsIdentifiedToNick(const User* user) override
+	{
+		if (user->IsModeSet(identifiedmode))
+			return true; // User has +r set.
+
+		// Check whether their current nick is in their nick list.
+		Account::NickList* nicks = accountnicksext.Get(user);
+		return nicks && stdalgo::isin(*nicks, user->nick);
+	}
 };
 
 class AccountExtBan final
@@ -240,26 +300,20 @@ public:
 		if (!request.GetFieldIndex('f', flag_index))
 			return MOD_RES_PASSTHRU;
 
-		if (user->IsModeSet(userregmode))
+		if (accountapi.IsIdentifiedToNick(user))
 			numeric.GetParams()[flag_index].push_back('r');
 
 		return MOD_RES_PASSTHRU;
 	}
 
-	/* <- :twisted.oscnet.org 330 w00t2 w00t2 w00t :is logged in as */
 	void OnWhois(Whois::Context& whois) override
 	{
 		const std::string* account = accountapi.GetAccountName(whois.GetTarget());
 		if (account)
-		{
 			whois.SendLine(RPL_WHOISACCOUNT, *account, "is logged in as");
-		}
 
-		if (whois.GetTarget()->IsModeSet(userregmode))
-		{
-			/* user is registered */
+		if (accountapi.IsIdentifiedToNick(whois.GetTarget()))
 			whois.SendLine(RPL_WHOISREGNICK, "is a registered nick");
-		}
 	}
 
 	void OnUserPostNick(User* user, const std::string& oldnick) override