Load config from file

src/client/java/net/vinrobot/mcemote/client/MinecraftEmoteModClient.java

@@ -7,7 +7,7 @@
 import net.vinrobot.mcemote.client.providers.IEmoteProvider;
 import net.vinrobot.mcemote.client.text.EmotesManager;
 import net.vinrobot.mcemote.config.Configuration;
-import net.vinrobot.mcemote.config.impl.ConfigurationImpl;
+import net.vinrobot.mcemote.config.ConfigurationService;
 import webpdecoderjn.WebPLoader;
 
 import java.io.IOException;
@@ -27,7 +27,7 @@ public void onInitializeClient() {
 			MinecraftEmoteMod.LOGGER.error("Failed to initialize WebPDecoder", e);
 		}
 
-		final Configuration config = new ConfigurationImpl();
+		final Configuration config = loadConfiguration(MinecraftEmoteMod.getConfigService());
 		final ServiceLoader<IEmoteProvider> serviceLoader = ServiceLoader.load(IEmoteProvider.class);
 		final List<IEmoteProvider> providers = ListHelper.sort(serviceLoader);
 
@@ -52,4 +52,14 @@ public void onInitializeClient() {
 			}
 		}
 	}
+
+	private Configuration loadConfiguration(final ConfigurationService service) {
+		try {
+			MinecraftEmoteMod.LOGGER.info("Loading config");
+			return service.load();
+		} catch (final IOException e) {
+			MinecraftEmoteMod.LOGGER.error("Failed to load config", e);
+			return service.create();
+		}
+	}
 }

src/main/java/net/vinrobot/mcemote/MinecraftEmoteMod.java

@@ -1,21 +1,40 @@
 package net.vinrobot.mcemote;
 
 import net.fabricmc.api.ModInitializer;
+import net.fabricmc.loader.api.FabricLoader;
+import net.vinrobot.mcemote.config.ConfigurationService;
+import net.vinrobot.mcemote.config.impl.file.FileConfigurationService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.nio.file.Path;
+
 public class MinecraftEmoteMod implements ModInitializer {
 	// This logger is used to write text to the console and the log file.
 	// It is considered best practice to use your mod id as the logger's name.
 	// That way, it's clear which mod wrote info, warnings, and errors.
 	public static final Logger LOGGER = LoggerFactory.getLogger("MCEmote");
 
+	private static ConfigurationService configService;
+
+	public static ConfigurationService getConfigService() {
+		ConfigurationService ret = configService;
+		if (ret == null) {
+			throw new RuntimeException("Configuration service not yet available!");
+		}
+		return ret;
+	}
+
 	@Override
 	public void onInitialize() {
 		// This code runs as soon as Minecraft is in a mod-load-ready state.
 		// However, some things (like resources) may still be uninitialized.
 		// Proceed with mild caution.
 
 		LOGGER.info("Hello Fabric world!");
+
+		final Path configDir = FabricLoader.getInstance().getConfigDir();
+		final Path configFile = configDir.resolve("mcemote.json");
+		configService = new FileConfigurationService(configFile);
 	}
 }

src/main/java/net/vinrobot/mcemote/config/ConfigurationService.java

@@ -0,0 +1,11 @@
+package net.vinrobot.mcemote.config;
+
+import java.io.IOException;
+
+public interface ConfigurationService {
+	Configuration create();
+
+	Configuration load() throws IOException;
+
+	void save(Configuration config) throws IOException;
+}

src/main/java/net/vinrobot/mcemote/config/TypedGson.java

@@ -0,0 +1,30 @@
+package net.vinrobot.mcemote.config;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonIOException;
+import com.google.gson.JsonSyntaxException;
+
+import java.io.Reader;
+
+public class TypedGson<S> {
+	private static final Gson DEFAULT_GSON = new GsonBuilder().setPrettyPrinting().create();
+
+	private final Gson gson;
+
+	public TypedGson() {
+		this(DEFAULT_GSON);
+	}
+
+	public TypedGson(final Gson gson) {
+		this.gson = gson;
+	}
+
+	public void toJson(S serializable, Appendable writer) throws JsonIOException {
+		this.gson.toJson(serializable, writer);
+	}
+
+	public <T extends S> T fromJson(Reader json, Class<T> classOfT) throws JsonSyntaxException, JsonIOException {
+		return this.gson.fromJson(json, classOfT);
+	}
+}

src/main/java/net/vinrobot/mcemote/config/impl/file/FileConfiguration.java

@@ -0,0 +1,17 @@
+package net.vinrobot.mcemote.config.impl.file;
+
+import net.vinrobot.mcemote.config.Configuration;
+
+import java.util.Optional;
+
+class FileConfiguration {
+	public String twitchId;
+
+	public void copyFrom(final Configuration domain) {
+		this.twitchId = domain.twitchId().get();
+	}
+
+	public void copyTo(final Configuration configuration) {
+		configuration.twitchId().set(Optional.ofNullable(this.twitchId));
+	}
+}

src/main/java/net/vinrobot/mcemote/config/impl/file/FileConfigurationService.java

@@ -0,0 +1,50 @@
+package net.vinrobot.mcemote.config.impl.file;
+
+import net.vinrobot.mcemote.config.Configuration;
+import net.vinrobot.mcemote.config.ConfigurationService;
+import net.vinrobot.mcemote.config.TypedGson;
+import net.vinrobot.mcemote.config.impl.ConfigurationImpl;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.Writer;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class FileConfigurationService implements ConfigurationService {
+	private final TypedGson<FileConfiguration> gson = new TypedGson<>();
+	private final Path configFile;
+
+	public FileConfigurationService(final Path configFile) {
+		this.configFile = configFile;
+	}
+
+	@Override
+	public Configuration create() {
+		return new ConfigurationImpl();
+	}
+
+	@Override
+	public Configuration load() throws IOException {
+		FileConfiguration fileConfiguration;
+		try (final Reader reader = Files.newBufferedReader(this.configFile)) {
+			fileConfiguration = this.gson.fromJson(reader, FileConfiguration.class);
+		}
+
+		final Configuration config = this.create();
+		if (fileConfiguration != null) {
+			fileConfiguration.copyTo(config);
+		}
+		return config;
+	}
+
+	@Override
+	public void save(final Configuration configuration) throws IOException {
+		final FileConfiguration fileConfiguration = new FileConfiguration();
+		fileConfiguration.copyFrom(configuration);
+
+		try (final Writer writer = Files.newBufferedWriter(this.configFile)) {
+			this.gson.toJson(fileConfiguration, writer);
+		}
+	}
+}