Add get_first_non_empty and use it into Database to simplify a little bit

CMakeLists.txt

@@ -96,7 +96,7 @@ if(LITESQL_FOUND)
 
   add_library(database STATIC src/database/database.cpp
     ${LITESQL_GENERATED_SOURCES})
-  target_link_libraries(database ${LITESQL_LIBRARIES})
+  target_link_libraries(database ${LITESQL_LIBRARIES} src_utils)
   if(BOTAN_FOUND)
     target_link_libraries(database ${BOTAN_LIBRARIES})
   endif()

src/database/database.cpp

@@ -4,8 +4,8 @@
 #include <database/database.hpp>
 #include <logger/logger.hpp>
 #include <irc/iid.hpp>
-#include <string>
 #include <uuid.h>
+#include <utils/get_first_non_empty.hpp>
 
 using namespace std::string_literals;
 
@@ -73,10 +73,11 @@ db::IrcChannelOptions Database::get_irc_channel_options_with_server_default(cons
 {
   auto coptions = Database::get_irc_channel_options(owner, server, channel);
   auto soptions = Database::get_irc_server_options(owner, server);
-  if (coptions.encodingIn.value().empty())
+
-    coptions.encodingIn = soptions.encodingIn;
+  coptions.encodingIn = get_first_non_empty(coptions.encodingIn.value(),
-  if (coptions.encodingOut.value().empty())
+                                            soptions.encodingIn.value());
-    coptions.encodingOut = soptions.encodingOut;
+  coptions.encodingOut = get_first_non_empty(coptions.encodingOut.value(),
+                                             soptions.encodingOut.value());
 
   return coptions;
 }

src/utils/get_first_non_empty.cpp

@@ -0,0 +1,11 @@
+#include <utils/get_first_non_empty.hpp>
+
+bool is_empty(const std::string& val)
+{
+  return val.empty();
+}
+
+bool is_empty(const int& val)
+{
+  return val == 0;
+}

src/utils/get_first_non_empty.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <string>
+
+bool is_empty(const std::string& val);
+bool is_empty(const int& val);
+
+template <typename T>
+T get_first_non_empty(T&& last)
+{
+  return last;
+}
+
+template <typename T, typename... Args>
+T get_first_non_empty(T&& first, Args&&... args)
+{
+  if (!is_empty(first))
+    return first;
+  return get_first_non_empty(std::forward<Args>(args)...);
+}

tests/utils.cpp

@@ -6,6 +6,9 @@
 #include <utils/split.hpp>
 #include <utils/xdg.hpp>
 #include <utils/empty_if_fixed_server.hpp>
+#include <utils/get_first_non_empty.hpp>
+
+using namespace std::string_literals;
 
 TEST_CASE("String split")
 {
@@ -100,3 +103,11 @@ TEST_CASE("string cut")
   CHECK(res[0] == "rhello, ");
   CHECK(res[1] == "♥");
 }
+
+TEST_CASE("first non-empty string")
+{
+  CHECK(get_first_non_empty(""s, ""s, "hello"s, "world"s) == "hello"s);
+  CHECK(get_first_non_empty(""s, ""s, ""s, ""s) == ""s);
+  CHECK(get_first_non_empty("first"s) == "first"s);
+  CHECK(get_first_non_empty(0, 1, 2, 3) == 1);
+}