From 37a820efcb53b9d6bda8f6821a5a0c0142b776a3 Mon Sep 17 00:00:00 2001
From: Sadie Powell <sadie@witchery.services>
Date: Sun, 27 Oct 2024 14:41:27 +0000
Subject: [PATCH] Add support for regex flags to the filter module.

---
 docs/conf/modules.example.conf |  8 +++++++-
 src/modules/m_filter.cpp       | 26 +++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/docs/conf/modules.example.conf b/docs/conf/modules.example.conf
index 3bd950f73..66593afa5 100644
--- a/docs/conf/modules.example.conf
+++ b/docs/conf/modules.example.conf
@@ -983,6 +983,9 @@
 # stdregex - stdlib regexps, provided via regex_stdlib, see comment   #
 #            at the <module> tag for info on availability.            #
 #                                                                     #
+# If enableflags is set, you can specify flags that modify matching   #
+# of the regular expression.                                          #
+#                                                                     #
 # If notifyuser is set to no, the user will not be notified when      #
 # their message is blocked.                                           #
 #                                                                     #
@@ -991,7 +994,10 @@
 # warning will be sent to opers instead. This stops spambots which    #
 # send their spam message to themselves first to check if it is being #
 # filtered by the server.                                             #
-#<filteropts engine="stdregex" notifyuser="yes" warnonselfmsg="no">
+#<filteropts engine="stdregex"
+#            enableflags="yes"
+#            notifyuser="yes"
+#            warnonselfmsg="no">
 #                                                                     #
 # Your choice of regex engine must match on all servers network-wide. #
 #                                                                     #
diff --git a/src/modules/m_filter.cpp b/src/modules/m_filter.cpp
index a84fce2b6..8fe610e7a 100644
--- a/src/modules/m_filter.cpp
+++ b/src/modules/m_filter.cpp
@@ -85,7 +85,7 @@ public:
 	bool flag_strip_color;
 	bool flag_no_registered;
 
-	FilterResult(Regex::EngineReference& RegexEngine, const std::string& free, const std::string& rea, FilterAction act, unsigned long gt, const std::string& fla, bool cfg)
+	FilterResult(Regex::EngineReference& RegexEngine, const std::string& free, const std::string& rea, FilterAction act, unsigned long gt, const std::string& fla, bool cfg, bool ef)
 		: freeform(free)
 		, reason(rea)
 		, action(act)
@@ -94,7 +94,7 @@ public:
 	{
 		if (!RegexEngine)
 			throw ModuleException(thismod, "Regex module implementing '"+RegexEngine.GetProvider()+"' is not loaded!");
-		regex = RegexEngine->Create(free);
+		regex = ef ? RegexEngine->CreateHuman(free) : RegexEngine->Create(free);
 		this->FillFlags(fla);
 	}
 
@@ -202,6 +202,7 @@ private:
 
 	Account::API accountapi;
 	bool initing = true;
+	bool enableflags;
 	bool notifyuser;
 	bool warnonselfmsg;
 	bool dirty = false;
@@ -233,6 +234,7 @@ public:
 	bool DeleteFilter(const std::string& freeform, std::string& reason);
 	std::pair<bool, std::string> AddFilter(const std::string& freeform, FilterAction type, const std::string& reason, unsigned long duration, const std::string& flags, bool config = false);
 	void ReadConfig(ConfigStatus& status) override;
+	void CompareLinkData(const LinkData& otherdata, LinkDataDiff& diffs) override;
 	void GetLinkData(LinkData& data, std::string& compatdata) override;
 	static std::string EncodeFilter(const FilterResult& filter);
 	FilterResult DecodeFilter(const std::string& data);
@@ -645,6 +647,7 @@ void ModuleFilter::ReadConfig(ConfigStatus& status)
 
 	const auto& tag = ServerInstance->Config->ConfValue("filteropts");
 	std::string newrxengine = tag->getString("engine");
+	enableflags = tag->getBool("enableflags");
 	notifyuser = tag->getBool("notifyuser", true);
 	warnonselfmsg = tag->getBool("warnonselfmsg");
 	filterconf = tag->getString("filename");
@@ -680,6 +683,20 @@ void ModuleFilter::ReadConfig(ConfigStatus& status)
 	ReadFilters();
 }
 
+void ModuleFilter::CompareLinkData(const LinkData& otherdata, LinkDataDiff& diffs)
+{
+	Module::CompareLinkData(otherdata, diffs);
+
+	auto it = diffs.find("flags");
+	if (it == diffs.end())
+		return; // Should never happen.
+
+	if (!it->second.first)
+		it->second.first = "no";
+	if (!it->second.second)
+		it->second.second = "no";
+}
+
 void ModuleFilter::GetLinkData(LinkData& data, std::string& compatdata)
 {
 	if (RegexEngine)
@@ -689,6 +706,9 @@ void ModuleFilter::GetLinkData(LinkData& data, std::string& compatdata)
 	}
 	else
 		data["regex"] = "broken";
+
+	if (enableflags)
+		data["flags"] = "yes";
 }
 
 std::string ModuleFilter::EncodeFilter(const FilterResult& filter)
@@ -815,7 +835,7 @@ std::pair<bool, std::string> ModuleFilter::AddFilter(const std::string& freeform
 
 	try
 	{
-		filters.emplace_back(RegexEngine, freeform, reason, type, duration, flgs, config);
+		filters.emplace_back(RegexEngine, freeform, reason, type, duration, flgs, config, enableflags);
 		dirty = true;
 	}
 	catch (const ModuleException& e)