Load default configs from the defaultconfig directory by default. (Can

be overridden in the fml.toml config file if desired).

Will load any type of config tracked file from there - client, common, server
or custom tracked file. This means you can ship defaults for your pack
in a defaultconfig directory. I am thinking about ways to force a specific
config override for an existing config.

Signed-off-by: cpw <cpw+github@weeksfamily.ca>

src/fmllauncher/java/net/minecraftforge/fml/loading/FMLConfig.java

@@ -27,6 +27,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.stream.Collectors;
 
@@ -41,6 +42,7 @@ public class FMLConfig
         configSpec.define("splashscreen", Boolean.TRUE);
         configSpec.define("maxThreads", -1);
         configSpec.define("versionCheck", Boolean.TRUE);
+        configSpec.define("defaultConfigPath",  "defaultconfigs");
     }
 
     private CommentedFileConfig configData;
@@ -69,6 +71,8 @@ public class FMLConfig
         LOGGER.trace(CORE, "Splash screen is {}", FMLConfig::splashScreenEnabled);
         LOGGER.trace(CORE, "Max threads for mod loading computed at {}", FMLConfig::loadingThreadCount);
         LOGGER.trace(CORE, "Version check is {}", FMLConfig::runVersionCheck);
+        LOGGER.trace(CORE, "Default config paths at {}", FMLConfig::defaultConfigPath);
+        FMLPaths.getOrCreateGameRelativePath(Paths.get(FMLConfig.defaultConfigPath()), "default config directory");
     }
 
     public static boolean splashScreenEnabled() {
@@ -84,4 +88,8 @@ public class FMLConfig
     public static boolean runVersionCheck() {
         return INSTANCE.configData.<Boolean>getOptional("versionCheck").orElse(Boolean.TRUE);
     }
+
+    public static String defaultConfigPath() {
+        return INSTANCE.configData.<String>getOptional("defaultConfigPath").orElse("defaultconfigs");
+    }
 }

src/fmllauncher/java/net/minecraftforge/fml/loading/FMLPaths.java

@@ -50,16 +50,16 @@ public enum FMLPaths
         this.isDirectory = true;
     }
 
-    private Path computePath(String... path)
-    {
-        return Paths.get(path[0], Arrays.copyOfRange(path, 1, path.length));
-    }
-
     FMLPaths(boolean isDir, FMLPaths parent, String... path) {
         this.relativePath = parent.relativePath.resolve(computePath(path));
         this.isDirectory = isDir;
     }
 
+    private Path computePath(String... path)
+    {
+        return Paths.get(path[0], Arrays.copyOfRange(path, 1, path.length));
+    }
+
     public static void setup(IEnvironment env) {
         final Path rootPath = env.getProperty(IEnvironment.Keys.GAMEDIR.get()).orElseThrow(() -> new RuntimeException("No game path found"));
 
@@ -79,6 +79,10 @@ public enum FMLPaths
         }
     }
 
+    public static Path getOrCreateGameRelativePath(Path path, String name) {
+        return FileUtils.getOrCreateDirectory(FMLPaths.GAMEDIR.get().resolve(path), name);
+    }
+
     public Path relative() {
         return relativePath;
     }

src/main/java/net/minecraftforge/fml/config/ConfigFileTypeHandler.java

@@ -19,13 +19,18 @@
 
 package net.minecraftforge.fml.config;
 
+import com.electronwill.nightconfig.core.ConfigFormat;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
+import com.electronwill.nightconfig.core.file.FileNotFoundAction;
 import com.electronwill.nightconfig.core.file.FileWatcher;
 import com.electronwill.nightconfig.core.io.WritingMode;
+import net.minecraftforge.fml.loading.FMLConfig;
+import net.minecraftforge.fml.loading.FMLPaths;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.function.Function;
 
@@ -34,6 +39,7 @@ import static net.minecraftforge.fml.config.ConfigTracker.CONFIG;
 public class ConfigFileTypeHandler {
     private static final Logger LOGGER = LogManager.getLogger();
     static ConfigFileTypeHandler TOML = new ConfigFileTypeHandler();
+    private static final Path defaultConfigPath = FMLPaths.GAMEDIR.get().resolve(FMLConfig.defaultConfigPath());
 
     public Function<ModConfig, CommentedFileConfig> reader(Path configBasePath) {
         return (c) -> {
@@ -41,6 +47,7 @@ public class ConfigFileTypeHandler {
             final CommentedFileConfig configData = CommentedFileConfig.builder(configPath).sync().
                     preserveInsertionOrder().
                     autosave().
+                    onFileNotFound((newfile, configFormat)-> setupConfigFile(c, newfile, configFormat)).
                     writingMode(WritingMode.REPLACE).
                     build();
             LOGGER.debug(CONFIG, "Built TOML config for {}", configPath.toString());
@@ -56,6 +63,18 @@ public class ConfigFileTypeHandler {
         };
     }
 
+    private boolean setupConfigFile(final ModConfig modConfig, final Path file, final ConfigFormat<?> conf) throws IOException {
+        Path p = defaultConfigPath.resolve(modConfig.getFileName());
+        if (Files.exists(p)) {
+            LOGGER.info(CONFIG, "Loading default config file from path {}", p);
+            Files.copy(p, file);
+        } else {
+            Files.createFile(file);
+            conf.initEmptyFile(file);
+        }
+        return true;
+    }
+
     private static class ConfigWatcher implements Runnable {
         private final ModConfig modConfig;
         private final CommentedFileConfig commentedFileConfig;