kerosene/src/main/java/pm/j4/kerosene/util/config/ConfigManager.java

package pm.j4.kerosene.util.config;

import com.google.common.reflect.TypeToken;
import com.google.gson.*;
import java.io.*;
import java.lang.reflect.Type;
import java.util.*;
import net.fabricmc.loader.api.FabricLoader;
import pm.j4.kerosene.KeroseneMod;
import pm.j4.kerosene.modules.bindings.BindingInfo;
import pm.j4.kerosene.util.data.ModuleConfig;
import pm.j4.kerosene.util.data.OptionSerializiable;
import pm.j4.kerosene.util.module.ModuleBase;

/**
 * The type Config manager.
 */
public class ConfigManager {
	/**
	 * The constant GSON.
	 */
	public static final Gson GSON = new GsonBuilder()
			.registerTypeAdapter(GlobalConfig.class, SerializationHelper.getGlobalSerializer())
			.registerTypeAdapter(GlobalConfig.class, SerializationHelper.getGlobalDeserializer())
			.setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES).setPrettyPrinting().create();
	/**
	 * The constant config.
	 */
	private static Map<String, ConfigHolder> configs = new HashMap<>();

	/**
	 * Prepare config file.
	 *
	 * @param path     the path
	 * @param filename the filename
	 * @return the file
	 */
	private static File prepareConfigFile(String path, String filename) {
		if (path != "") {
			File directory = new File(FabricLoader.getInstance().getConfigDir().toString(), path);
			if (!directory.exists()) directory.mkdir();
		}
		return new File(FabricLoader.getInstance().getConfigDir().toString(), path + filename);
	}

	/**
	 * Init config.
	 */
	public static void initConfig(String moduleName) {
		if (configs.containsKey(moduleName)) {
			return;
		}

		ConfigHolder config = new ConfigHolder();
		config.globalConfig = new DefaultConfig();
		config.serverConfigs = new HashMap<>();

		config = load(moduleName + "/", moduleName +".json", ConfigHolder.class);
		initModules(moduleName);
	}

	/**
	 * Init modules.
	 */
	public static void initModules(String moduleName) {
		KeroseneMod.getRegisteredMods().forEach(module -> {
			ModuleConfig options = load(moduleName + "/modules/", module.getModuleName() + ".json", ModuleConfig.class);
			if (options != null && options.options != null) {
				options.options.forEach((key, option) -> {
					if (module.hasOption(option.key)) {
						module.setConfigOption(option.key, option.value);
					}
				});
			}
		});
	}

	/**
	 * Load.
	 *
	 * @param <T>      the type parameter
	 * @param path     the path
	 * @param filename the filename
	 * @param tClass   the t class
	 * @return the t
	 */
	private static <T> T load(String path, String filename, Class<T> tClass) {
		File file = prepareConfigFile(path, filename);

		try {
			if (!file.exists()) {
				save(path, filename, tClass.newInstance());
			}
			if (file.exists()) {
				BufferedReader reader = new BufferedReader(new FileReader(file));
				T parsedConfig = null;
				try {
					parsedConfig = GSON.fromJson(reader, tClass);
				} catch (Exception e) {
					System.out.println("Couldn't parse config file");
					e.printStackTrace();
				}
				if (parsedConfig != null) {
					return parsedConfig;
				}
			}
		} catch (FileNotFoundException | InstantiationException | IllegalAccessException e) {
			System.out.println("Couldn't load configuration file at " + path);
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * Deserialize element t.
	 *
	 * @param <T>     the type parameter
	 * @param element the element
	 * @param tClass  the t class
	 * @return the t
	 */
	public static <T> T deserializeElement(JsonElement element, Class<T> tClass) {
		return GSON.fromJson(element, tClass);
	}

	/**
	 * Save.
	 *
	 * @param <T>      the type parameter
	 * @param path     the path
	 * @param filename the filename
	 * @param data     the data
	 */
	private static <T> void save(String path, String filename, T data) {
		File file = prepareConfigFile(path, filename);

		String json = GSON.toJson(data);
		try (FileWriter fileWriter = new FileWriter(file)) {
			fileWriter.write(json);
		} catch (IOException e) {
			System.out.println("Couldn't save configuration file at " + path);
			e.printStackTrace();
		}
	}

	/**
	 * Save module.
	 *
	 * @param b the b
	 */
	public static void saveModule(String modName, ModuleBase b) {
		ModuleConfig c = new ModuleConfig();
		c.options = GlobalConfig.serializeModuleConfiguration(b);
		save(modName + "/modules/", b.getModuleName() + ".json", c);
	}

	/**
	 * Save all modules.
	 */
	public static void saveAllModules() {
		List<ModuleBase> mods = KeroseneMod.getRegisteredMods();
		mods.forEach((module) -> {
			ConfigManager.saveModule(module.getParent(), module);
		});
	}

	/**
	 * Save global config.
	 */
	public static void saveGlobalConfig(String modName) {
		if(configs.containsKey(modName)) {
			save(modName + "/", modName + ".json", configs.get(modName));
		}
	}

	/**
	 * Gets config.
	 *
	 * @return the config
	 */
	public static Optional<ConfigHolder> getConfig(String modName) {
		if (configs.containsKey(modName)) {
			return Optional.of(configs.get(modName));
		}
		return Optional.empty();
	}
}

/**
 * The type Serialization helper.
 */
class SerializationHelper {

	/**
	 * The constant s.
	 */
	private static final JsonSerializer<GlobalConfig> GLOBAL_CONFIG_JSON_SERIALIZER = (src, typeOfSrc, ctx) -> {
		JsonObject jsonConfig = new JsonObject();

		JsonArray bindings = ctx.serialize(src.serializeBindings()).getAsJsonArray();
		jsonConfig.add("bindings", bindings);

		JsonArray modules = ctx.serialize(src.enabledModules).getAsJsonArray();
		jsonConfig.add("enabled_modules", modules);

		return jsonConfig;
	};

	/**
	 * The constant ds.
	 */
	private static final JsonDeserializer<GlobalConfig> GLOBAL_CONFIG_JSON_DESERIALIZER = ((json, typeOfT, ctx) -> {
		JsonObject obj = json.getAsJsonObject();

		List<BindingInfo> bindings = new ArrayList<>();
		if (obj.has("bindings")) {
			obj.get("bindings").getAsJsonArray().forEach(b -> bindings.add(ctx.deserialize(b, BindingInfo.class)));
		}
		List<String> modules = new ArrayList<>();
		if (obj.has("enabled_modules")) {
			obj.get("enabled_modules").getAsJsonArray().forEach(m -> modules.add(m.getAsString()));
		}
		GlobalConfig cfg = new GlobalConfig();
		Map<String, List<OptionSerializiable>> options;
		Type type = new TypeToken<Map<String, List<OptionSerializiable>>>() {
		}.getType();
		if (obj.has("module_configuration")) {
			options = ctx.deserialize(obj.get("module_configuration"), type);
		} else {
			options = new HashMap<>();
		}
		KeroseneMod.getRegisteredMods().forEach(module -> {
			if (options.containsKey(module.getModuleName())) {
				cfg.deserializeModuleConfiguration(options.get(module.getModuleName()), module);
			}
		});
		cfg.deserializeBindings(bindings);
		cfg.enabledModules = modules;
		return cfg;
	});

	/**
	 * Gets serializer.
	 *
	 * @return the serializer
	 */
	public static JsonSerializer<GlobalConfig> getGlobalSerializer() {
		return GLOBAL_CONFIG_JSON_SERIALIZER;
	}

	/**
	 * Gets deserializer.
	 *
	 * @return the deserializer
	 */
	public static JsonDeserializer<GlobalConfig> getGlobalDeserializer() {
		return GLOBAL_CONFIG_JSON_DESERIALIZER;
	}
}