refactor: separate regex rule matching and caching in separate class

include/util/regex_collection.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <json/json.h>
+
+#include <functional>
+#include <regex>
+#include <string>
+
+namespace waybar::util {
+
+struct Rule {
+  std::regex rule;
+  std::string repr;
+  int priority;
+};
+
+int default_priority_function(std::string& key);
+
+class RegexCollection {
+ private:
+  std::vector<Rule> rules;
+  std::map<std::string, std::string> regex_cache;
+  std::string default_repr;
+
+  std::string& find_match(std::string& value, bool& matched_any);
+
+ public:
+  RegexCollection() = default;
+  RegexCollection(const Json::Value& map, std::string default_repr = "",
+                  std::function<int(std::string&)> priority_function = default_priority_function);
+  ~RegexCollection() = default;
+
+  std::string& get(std::string& value, bool& matched_any);
+  std::string& get(std::string& value);
+};
+
+}  // namespace waybar::util