settings system

src/main/java/carpet/CarpetServer.java

@@ -10,6 +10,7 @@ import carpet.commands.DistanceCommand;
 import carpet.commands.DrawCommand;
 import carpet.commands.InfoCommand;
 import carpet.commands.LogCommand;
+import carpet.commands.ParcetCommand;
 import carpet.commands.PerimeterInfoCommand;
 import carpet.commands.PlayerCommand;
 import carpet.commands.ScriptCommand;
@@ -18,6 +19,8 @@ import carpet.commands.TickCommand;
 import carpet.helpers.TickSpeed;
 import carpet.logging.LoggerRegistry;
 import carpet.script.CarpetScriptServer;
+import carpet.settings.Settings;
+import carpet.settings.SettingsManager;
 import carpet.utils.HUDController;
 import com.mojang.brigadier.CommandDispatcher;
 import net.minecraft.server.command.ServerCommandSource;
@@ -28,12 +31,21 @@ public class CarpetServer // static for now - easier to handle all around the co
     public static final Random rand = new Random((int)((2>>16)*Math.random()));
     public static MinecraftServer minecraft_server;
     public static CarpetScriptServer scriptServer;
+    public static SettingsManager settingsManager;
+    static {
+        SettingsManager.parseSettingsClass(Settings.class);
+        //...
+    }
     public static void init(MinecraftServer server) //aka constructor of this static singleton class
     {
         CarpetServer.minecraft_server = server;
     }
     public static void onServerLoaded(MinecraftServer server)
     {
+        //new
+        settingsManager = new SettingsManager(server);
+
+        //old
         CarpetSettings.apply_settings_from_conf(server);
         scriptServer = new CarpetScriptServer();
     }
@@ -65,6 +77,7 @@ public class CarpetServer // static for now - easier to handle all around the co
         PerimeterInfoCommand.register(dispatcher);
         DrawCommand.register(dispatcher);
         ScriptCommand.register(dispatcher);
+        ParcetCommand.register(dispatcher);
 
         //TestCommand.register(dispatcher);
     }

src/main/java/carpet/CarpetSettings.java

@@ -7,6 +7,7 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.server.dedicated.DedicatedServer;
 import net.minecraft.server.network.ServerPlayerEntity;
+import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -214,19 +215,19 @@ public class CarpetSettings
 
     public static void apply_settings_from_conf(MinecraftServer server)
     {
-        Map<String, String> conf = read_conf(server);
-        boolean is_locked = locked;
+        Pair<Map<String, String>,Boolean> conf = read_conf(server);
         locked = false;
-        if (is_locked)
+        if (conf.getRight())
         {
             LOG.info("[CM]: Carpet Mod is locked by the administrator");
+            disable_commands_by_default();
         }
-        for (String key: conf.keySet())
+        for (String key: conf.getLeft().keySet())
         {
-            set(server.getCommandSource(), key, conf.get(key));
-            LOG.info("[CM]: loaded setting "+key+" as "+conf.get(key)+" from carpet.conf");
+            set(server.getCommandSource(), key, conf.getLeft().get(key));
+            LOG.info("[CM]: loaded setting "+key+" as "+conf.getLeft().get(key)+" from carpet.conf");
         }
-        locked = is_locked;
+        locked = conf.getRight();
     }
     private static void disable_commands_by_default()
     {
@@ -239,21 +240,21 @@ public class CarpetSettings
         }
     }
 
-    private static Map<String, String> read_conf(MinecraftServer server)
+    private static Pair<Map<String, String>,Boolean> read_conf(MinecraftServer server)
     {
         try
         {
             File settings_file = server.getLevelStorage().resolveFile(server.getLevelName(), "carpet.conf");
             BufferedReader b = new BufferedReader(new FileReader(settings_file));
             String line = "";
+            boolean confLocked = false;
             Map<String,String> result = new HashMap<String, String>();
             while ((line = b.readLine()) != null)
             {
                 line = line.replaceAll("\\r|\\n", "");
                 if ("locked".equalsIgnoreCase(line))
                 {
-                    disable_commands_by_default();
-                    locked = true;
+                    confLocked = true;
                 }
                 String[] fields = line.split("\\s+",2);
                 if (fields.length > 1)
@@ -272,16 +273,16 @@ public class CarpetSettings
                 }
             }
             b.close();
-            return result;
+            return Pair.of(result, confLocked);
         }
         catch(FileNotFoundException e)
         {
-            return new HashMap<>();
+            return Pair.of(new HashMap<>(), false);
         }
         catch (IOException e)
         {
             e.printStackTrace();
-            return new HashMap<>();
+            return Pair.of(new HashMap<>(), false);
         }
         
     }
@@ -311,9 +312,10 @@ public class CarpetSettings
         if (locked) return false;
         if (settings_store.containsKey(setting_name))
         {
-            Map<String, String> conf = read_conf(source.getMinecraftServer());
-            conf.put(setting_name, string_value);
-            write_conf(source.getMinecraftServer(), conf);
+            Pair<Map<String, String>,Boolean> conf = read_conf(source.getMinecraftServer());
+            conf.getLeft().put(setting_name, string_value);
+            write_conf(source.getMinecraftServer(), conf.getLeft()); // this may feels weird, but if conf
+            // is locked, it will never reach this point.
             set(source, setting_name,string_value);
             return true;
         }
@@ -325,9 +327,9 @@ public class CarpetSettings
         if (locked) return false;
         if (settings_store.containsKey(setting_name))
         {
-            Map<String, String> conf = read_conf(source.getMinecraftServer());
-            conf.remove(setting_name);
-            write_conf(source.getMinecraftServer(), conf);
+            Pair<Map<String, String>,Boolean> conf = read_conf(source.getMinecraftServer());
+            conf.getLeft().remove(setting_name);
+            write_conf(source.getMinecraftServer(), conf.getLeft());
             set(source, setting_name,get(setting_name).getDefault());
             return true;
         }
@@ -386,7 +388,7 @@ public class CarpetSettings
     public static CarpetSettingEntry[] find_nondefault(MinecraftServer server)
     {
         ArrayList<CarpetSettingEntry> res = new ArrayList<CarpetSettingEntry>();
-        Map <String,String> defaults = read_conf(server);
+        Map <String,String> defaults = read_conf(server).getLeft();
         for (String rule: settings_store.keySet().stream().sorted().collect(Collectors.toList()))
         {
             if (!settings_store.get(rule).isDefault() || defaults.containsKey(rule))
@@ -400,7 +402,7 @@ public class CarpetSettings
     {
         ArrayList<CarpetSettingEntry> res = new ArrayList<CarpetSettingEntry>();
         if (locked) return res.toArray(new CarpetSettingEntry[0]);
-        Map <String,String> defaults = read_conf(server);
+        Map <String,String> defaults = read_conf(server).getLeft();
         for (String rule: settings_store.keySet().stream().sorted().collect(Collectors.toList()))
         {
             if (defaults.containsKey(rule))

src/main/java/carpet/commands/ParcetCommand.java

@@ -0,0 +1,209 @@
+package carpet.commands;
+
+import carpet.CarpetServer;
+import carpet.CarpetSettings;
+import carpet.settings.ParsedRule;
+import carpet.settings.RuleCategory;
+import carpet.settings.SettingsManager;
+import carpet.utils.Messenger;
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import net.minecraft.server.command.ServerCommandSource;
+import net.minecraft.server.command.CommandManager;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.text.BaseText;
+import net.minecraft.text.Text;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static net.minecraft.server.command.CommandManager.argument;
+import static net.minecraft.server.command.CommandManager.literal;
+import static net.minecraft.server.command.CommandSource.suggestMatching;
+
+public class ParcetCommand
+{
+    public static void register(CommandDispatcher<ServerCommandSource> dispatcher)
+    {
+        LiteralArgumentBuilder<ServerCommandSource> literalargumentbuilder = literal("parcet").requires((player) ->
+                player.hasPermissionLevel(2) && !CarpetServer.settingsManager.locked);
+
+        literalargumentbuilder.executes((context)->listAllSettings(context.getSource())).
+                then(literal("list").
+                        executes( (c) -> listSettings(c.getSource(),
+                                "All CarpetMod Settings",
+                                SettingsManager.getRules())).
+                        then(literal("defaults").
+                                executes( (c)-> listSettings(c.getSource(),
+                                        "Current CarpetMod Startup Settings from carpet.conf",
+                                        CarpetServer.settingsManager.findStartupOverrides()))).
+                        then(argument("tag",StringArgumentType.word()).
+                                suggests( (c, b)->suggestMatching(Arrays.stream(RuleCategory.values()).map(r -> r.lowerCase), b)).
+                                executes( (c) -> listSettings(c.getSource(),
+                                        String.format("CarpetMod Settings matching \"%s\"", StringArgumentType.getString(c, "tag")),
+                                        CarpetServer.settingsManager.getRulesMatching(StringArgumentType.getString(c, "tag"))))));
+
+        for (ParsedRule<?> rule: SettingsManager.getRules())
+        {
+            literalargumentbuilder.then(literal(rule.name).executes( (context) ->
+                    displayRuleMenu(context.getSource(),rule)));
+            literalargumentbuilder.then(literal("removeDefault").
+                    requires(s -> !CarpetServer.settingsManager.locked).
+                    then(literal(rule.name).executes((context) ->
+                            removeDefault(context.getSource(), rule))));
+            literalargumentbuilder.then(literal(rule.name).
+                    requires(s -> !CarpetServer.settingsManager.locked).
+                    then(argument("value", StringArgumentType.word()).
+                            suggests((c, b)-> suggestMatching(rule.options,b)).
+                            executes((context) ->
+                                    setRule(context.getSource(), rule, StringArgumentType.getString(context, "value")))));
+            literalargumentbuilder.then(literal("setDefault").
+                    requires(s -> !CarpetServer.settingsManager.locked).
+                    then(literal(rule.name).
+                            then(argument("value", StringArgumentType.word()).
+                                    suggests((c, b)-> suggestMatching(rule.options,b)).
+                                    executes((context) ->
+                                            setDefault(context.getSource(), rule, StringArgumentType.getString(context, "value"))))));
+        }
+        dispatcher.register(literalargumentbuilder);
+    }
+
+    private static int displayRuleMenu(ServerCommandSource source, ParsedRule<?> rule)
+    {
+        PlayerEntity player;
+        try
+        {
+            player = source.getPlayer();
+        }
+        catch (CommandSyntaxException e)
+        {
+            Messenger.m(source, "w "+rule.name +" is set to: ","wb "+rule.getAsString());
+            return 1;
+        }
+
+        Messenger.m(player, "");
+        Messenger.m(player, "wb "+rule.name,"!/carpet "+rule.name,"^g refresh");
+        Messenger.m(player, "w "+rule.description);
+
+        rule.extraInfo.forEach(s -> Messenger.m(player, "g  "+s));
+
+        List<BaseText> tags = new ArrayList<>();
+        tags.add(Messenger.c("w Tags: "));
+        for (String t: Arrays.stream(RuleCategory.values()).sorted().map(c -> c.lowerCase).collect(Collectors.toList()))
+        {
+            tags.add(Messenger.c("c ["+t+"]", "^g list all "+t+" settings","!/carpet list "+t));
+            tags.add(Messenger.c("w , "));
+        }
+        tags.remove(tags.size()-1);
+        Messenger.m(player, tags.toArray(new Object[0]));
+
+        Messenger.m(player, "w Current value: ",String.format("%s %s (%s value)",rule.getBoolValue()?"lb":"nb", rule.getAsString(),rule.isDefault()?"default":"modified"));
+        List<BaseText> options = new ArrayList<>();
+        options.add(Messenger.c("w Options: ", "y [ "));
+        for (String o: rule.options)
+        {
+            options.add(makeSetRuleButton(rule, o, false));
+            options.add(Messenger.c("w  "));
+        }
+        options.remove(options.size()-1);
+        options.add(Messenger.c("y  ]"));
+        Messenger.m(player, options.toArray(new Object[0]));
+
+        return 1;
+    }
+
+    private static int setRule(ServerCommandSource source, ParsedRule<?> rule, String newValue)
+    {
+        if (rule.set(source, newValue) != null)
+            Messenger.m(source, "w "+rule.toString()+", ", "c [change permanently?]",
+                    "^w Click to keep the settings in carpet.conf to save across restarts",
+                    "?/carpet setDefault "+rule.name+" "+rule.getAsString());
+        return 1;
+    }
+    private static int setDefault(ServerCommandSource source, ParsedRule<?> rule, String defaultValue)
+    {
+        CarpetServer.settingsManager.setDefaultRule(source, rule.name, defaultValue);
+        Messenger.m(source ,"gi rule "+ rule.name+" will now default to "+ defaultValue);
+        return 1;
+    }
+    private static int removeDefault(ServerCommandSource source, ParsedRule<?> rule)
+    {
+        CarpetServer.settingsManager.removeDefaultRule(source, rule.name);
+        Messenger.m(source ,"gi rule "+ rule.name+" defaults to Vanilla");
+        return 1;
+    }
+
+
+    private static BaseText displayInteractiveSetting(ParsedRule<?> rule)
+    {
+        List<Object> args = new ArrayList<>();
+        args.add("w - "+rule.name+" ");
+        args.add("!/carpet "+rule.name);
+        args.add("^y "+rule.description);
+        for (String option: rule.options)
+        {
+            args.add(makeSetRuleButton(rule, option, true));
+            args.add("w  ");
+        }
+        args.remove(args.size()-1);
+        return Messenger.c(args.toArray(new Object[0]));
+    }
+
+    private static BaseText makeSetRuleButton(ParsedRule<?> rule, String option, boolean brackets) {
+        String color = "";
+        if (option.equals(rule.defaultAsString) && !brackets) color += "u";
+        color += option.equals(rule.getAsString()) ? "bl" : "y";
+        String baseText = color + (brackets ? " [" : " ") + option + (brackets ? "]" : "");
+        if (CarpetServer.settingsManager.locked) {
+            return Messenger.c(baseText, "^g Settings are locked");
+        }
+        return Messenger.c(baseText, "^g Switch to " + option, "?/carpet " + rule.name + " " + option);
+    }
+
+    private static int listSettings(ServerCommandSource source, String title, Collection<ParsedRule<?>> settings_list)
+    {
+        try
+        {
+            PlayerEntity player = source.getPlayer();
+            Messenger.m(player,String.format("wb %s:",title));
+            settings_list.forEach(e -> Messenger.m(player,displayInteractiveSetting(e)));
+
+        }
+        catch (CommandSyntaxException e)
+        {
+            Messenger.m(source, "w s:"+title);
+            settings_list.forEach(r -> Messenger.m(source, "w  - "+ r.toString()));
+        }
+        return 1;
+    }
+    private static int listAllSettings(ServerCommandSource source)
+    {
+        listSettings(source, "Current CarpetMod Settings", CarpetServer.settingsManager.getNonDefault());
+
+        Messenger.m(source, "Carpet Mod version: "+ CarpetSettings.carpetVersion);
+        try
+        {
+            PlayerEntity player = source.getPlayer();
+            List<Object> tags = new ArrayList<>();
+            tags.add("w Browse Categories:\n");
+            for (String t : Arrays.stream(RuleCategory.values()).map(r -> r.lowerCase).collect(Collectors.toList()))
+            {
+                tags.add("c [" + t+"]");
+                tags.add("^g list all " + t + " settings");
+                tags.add("!/carpet list " + t);
+                tags.add("w  ");
+            }
+            tags.remove(tags.size() - 1);
+            Messenger.m(player, tags.toArray(new Object[0]));
+        }
+        catch (CommandSyntaxException e)
+        {
+        }
+        return 1;
+    }
+}

src/main/java/carpet/settings/ParsedRule.java

@@ -0,0 +1,170 @@
+package carpet.settings;
+
+import carpet.utils.Messenger;
+import com.google.common.collect.ImmutableList;
+import net.minecraft.server.command.ServerCommandSource;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+
+public final class ParsedRule<T> implements Comparable<ParsedRule> {
+    public final Rule rule;
+    public final Field field;
+
+    public final String name;
+    public final String description;
+    public final ImmutableList<String> extraInfo;
+    public final ImmutableList<RuleCategory> categories;
+    public final ImmutableList<String> options;
+    public boolean isStrict;
+    public final Class<T> type;
+    public final List<Validator<T>> validators;
+    public final T defaultValue;
+    public final String defaultAsString;
+
+    public static <T> T callConstructor(Class<T> cls) {
+        try {
+            Constructor<T> constr = cls.getDeclaredConstructor();
+            constr.setAccessible(true);
+            return constr.newInstance();
+        } catch (ReflectiveOperationException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    ParsedRule(Field field, Rule rule) {
+        this.rule = rule;
+        this.field = field;
+        this.name = rule.name().isEmpty() ? field.getName() : rule.name();
+        this.type = (Class<T>) field.getType();
+        this.description = rule.desc();
+        this.isStrict = rule.strict();
+        this.extraInfo = ImmutableList.copyOf(rule.extra());
+        this.categories = ImmutableList.copyOf(rule.category());
+        this.validators = new ArrayList<>();
+        for (Class v : rule.validate())
+        {
+            this.validators.add((Validator<T>) callConstructor(v));
+        }
+        if (categories.contains(RuleCategory.COMMANDS))
+            this.validators.add(callConstructor(Validator._COMMAND.class));
+
+        this.defaultValue = get();
+        this.defaultAsString = convertToString(this.defaultValue);
+        if (this.type == boolean.class) {
+            this.isStrict = true; // it has no sense otherwise
+            this.options = ImmutableList.of("true", "false");
+        } else if (this.type.isEnum()) {
+            this.isStrict = true; // it has no sense otherwise
+            this.options = Arrays.stream(this.type.getEnumConstants()).map(e -> ((Enum) e).name().toLowerCase(Locale.ROOT)).collect(ImmutableList.toImmutableList());
+        } else {
+            this.options = ImmutableList.copyOf(rule.options());
+        }
+        if (isStrict)
+            this.validators.add(callConstructor(Validator._STRICT.class));
+    }
+
+
+    public ParsedRule<T> set(ServerCommandSource source, String value) {
+        //if locked - prevent
+        if (type == String.class)
+        {
+            return set(source, (T) value, value);
+        }
+        else if (type == boolean.class)
+        {
+            return set(source, (T) (Object) Boolean.parseBoolean(value), value);
+        }
+        else if (type == int.class)
+        {
+            return set(source, (T) (Object) Integer.parseInt(value), value);
+        }
+        else if (type.isEnum())
+        {
+            String ucValue = value.toUpperCase(Locale.ROOT);
+            return set(source, (T) (Object) Enum.valueOf((Class<? extends Enum>) type, ucValue), value);
+        }
+        else
+        {
+            Messenger.m(source, "r Unknown type " + type.getSimpleName());
+            return null;
+        }
+    }
+
+    public ParsedRule<T> set(ServerCommandSource source, T value, String stringValue) {
+        try {
+            for (Validator<T> validator : this.validators)
+            {
+                boolean allowed = validator.validate(source, this, value, stringValue);
+                if (!allowed)
+                {
+                    Messenger.m(source, "r Wrong value for " + name + ": " + stringValue);
+                    return null;
+                }
+            }
+            this.field.set(null, value);
+
+        }
+        catch (IllegalAccessException e)
+        {
+            Messenger.m(source, "r Unable to access setting for  "+name);
+        }
+        return this;
+    }
+
+    public T get() {
+        try {
+            return (T) this.field.get(null);
+        } catch (IllegalAccessException e) {
+            throw new IllegalStateException(e);
+        }
+    }
+
+    public String getAsString() {
+        return convertToString(get());
+    }
+
+    public boolean getBoolValue() {
+        if (type == boolean.class) return (Boolean) get();
+        if (type.isAssignableFrom(Number.class)) return ((Number) get()).doubleValue() > 0;
+        return false;
+    }
+
+    public boolean isDefault() {
+        return defaultValue.equals(get());
+    }
+
+    public void resetToDefault(ServerCommandSource source) {
+        set(source, defaultValue, defaultAsString);
+    }
+
+
+    private static String convertToString(Object value) {
+        if (value instanceof Enum) return ((Enum) value).name().toLowerCase(Locale.ROOT);
+        return value.toString();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        return obj.getClass() == ParsedRule.class && ((ParsedRule) obj).name.equals(this.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return this.name.hashCode();
+    }
+
+    @Override
+    public int compareTo(ParsedRule o) {
+        return this.name.compareTo(o.name);
+    }
+
+    @Override
+    public String toString() {
+        return this.name + ": " + getAsString();
+    }
+}

src/main/java/carpet/settings/Rule.java

@@ -0,0 +1,58 @@
+package carpet.settings;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Any field in this class annotated with this class is interpreted as a carpet rule.
+ * The field must be static and have a type of one of:
+ * - boolean
+ * - int
+ * - double
+ * - String
+ * - a subclass of Enum
+ * The default value of the rule will be the initial value of the field.
+ */
+@Target(ElementType.FIELD)
+@Retention(RetentionPolicy.RUNTIME)
+@interface Rule {
+    /**
+     * The rule name, by default the same as the field name
+     */
+    String name() default ""; // default same as field name
+
+    /**
+     * A description of the rule
+     */
+    String desc();
+
+    /**
+     * Extra information about the rule
+     */
+    String[] extra() default {};
+
+    /**
+     * A list of categories the rule is in
+     */
+    RuleCategory[] category();
+
+    /**
+     * Options to select in menu.
+     * Inferred for booleans and enums. Otherwise, must be present.
+     */
+    String[] options() default {};
+
+    /**
+     * if a rule is not strict - can take any value, otherwise it needs to match
+     * any of the options
+     * For enums, its always strict
+     */
+    boolean strict() default true;
+
+    /**
+     * The class of the validator checked when the rule is changed.
+     */
+    Class<? extends Validator>[] validate() default {};
+}

src/main/java/carpet/settings/RuleCategory.java

@@ -0,0 +1,13 @@
+package carpet.settings;
+
+import java.util.Locale;
+
+public enum RuleCategory {
+    BUGFIX, SURVIVAL, CREATIVE, EXPERIMENTAL, OPTIMIZATIONS, FEATURE, COMMANDS ;
+
+    public final String lowerCase;
+
+    RuleCategory() {
+        this.lowerCase = this.name().toLowerCase(Locale.ROOT);
+    }
+}

src/main/java/carpet/settings/Settings.java

@@ -0,0 +1,84 @@
+package carpet.settings;
+
+import static carpet.settings.RuleCategory.BUGFIX;
+import static carpet.settings.RuleCategory.COMMANDS;
+import static carpet.settings.RuleCategory.CREATIVE;
+import static carpet.settings.RuleCategory.EXPERIMENTAL;
+import static carpet.settings.RuleCategory.FEATURE;
+import static carpet.settings.RuleCategory.OPTIMIZATIONS;
+import static carpet.settings.RuleCategory.SURVIVAL;
+
+public class Settings
+{
+    @Rule(
+            desc = "Fixes server crashing supposedly on falling behind 60s in ONE tick, yeah bs.",
+            extra = "Fixed 1.12 watchdog crash in 1.13 pre-releases, reintroduced with 1.13, GG.",
+            category = BUGFIX,
+            validate = Validator.WIP.class
+    )
+    public static boolean watchdogCrashFix = false;
+
+    @Rule(
+        desc = "Enables /c and /s commands to quickly switch between camera and survival modes",
+        extra = "/c and /s commands are available to all players regardless of their permission levels",
+        category = COMMANDS
+    )
+    public static boolean commandCameramode = true;
+
+    @Rule(desc = "fill/clone/setblock and structure blocks cause block updates", category = CREATIVE)
+    public static boolean fillUpdates = true;
+
+    @Rule(
+        desc = "Customizable fill/clone volume limit",
+        options = {"32768", "250000", "1000000"},
+        validate = Validator.POSITIVE_NUMBER.class,
+        category = CREATIVE
+    )
+    public static int fillLimit = 32768;
+
+    @Rule(
+        desc = "Hoppers pointing to wool will count items passing through them",
+        extra = {
+            "Enables /counter command, and actions while placing red and green carpets on wool blocks",
+            "Use /counter <color?> reset to reset the counter, and /counter <color?> to query",
+            "In survival, place green carpet on same color wool to query, red to reset the counters",
+            "Counters are global and shared between players, 16 channels available",
+            "Items counted are destroyed, count up to one stack per tick per hopper"
+        },
+        category = COMMANDS
+    )
+    public static boolean hopperCounters = false;
+
+    @Rule(desc = "Explosions won't destroy blocks", category = CREATIVE)
+    public static boolean explosionNoBlockDamage = false;
+
+    @Rule(
+        desc = "Silverfish drop a gravel item when breaking out of a block",
+        category = {FEATURE, EXPERIMENTAL}
+    )
+    public static boolean silverFishDropGravel = false;
+
+    @Rule(desc = "Shulkers will respawn in end cities", category = {FEATURE, EXPERIMENTAL})
+    public static boolean shulkerSpawningInEndCities = false;
+
+    @Rule(
+        desc = "Portals won't let a creative player go through instantly",
+        extra = "Holding obsidian in either hand won't let you through at all",
+        category = CREATIVE
+    )
+    public static boolean portalCreativeDelay = false;
+
+    @Rule(desc = "Pistons can push block entities, like hoppers, chests etc.", category = {FEATURE, EXPERIMENTAL})
+    public static boolean movableTileEntities = false;
+    
+    @Rule(
+        desc = "Empty shulker boxes can stack to 64 when dropped on the ground",
+        extra = "To move them around between inventories, use shift click to move entire stacks",
+        category = SURVIVAL
+    )
+    public static boolean stackableShulkerBoxes = false;
+
+    @Rule(desc = "Optimizes spawning", category = {OPTIMIZATIONS, EXPERIMENTAL})
+    public static boolean lagFreeSpawning = false;
+
+}

src/main/java/carpet/settings/SettingsManager.java

@@ -0,0 +1,230 @@
+package carpet.settings;
+
+import carpet.CarpetSettings;
+import com.google.common.collect.ImmutableList;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.command.ServerCommandSource;
+import net.minecraft.server.network.ServerPlayerEntity;
+import org.apache.commons.lang3.tuple.Pair;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.*;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+
+public class SettingsManager {
+    private static final Logger LOG = LogManager.getLogger();
+    private static Map<String, ParsedRule<?>> rules = new HashMap<>();
+    public boolean locked;
+    MinecraftServer server;
+
+    public SettingsManager(MinecraftServer server)
+    {
+        this.server = server;
+        loadConfigurationFromConf();
+    }
+
+
+    public static void parseSettingsClass(Class settingsClass)
+    {
+        for (Field f : settingsClass.getDeclaredFields())
+        {
+            Rule rule = f.getAnnotation(Rule.class);
+            if (rule == null) continue;
+            ParsedRule parsed = new ParsedRule(f, rule);
+            CarpetSettings.LOG.error("REGISTERED RULE: "+parsed.name);
+            rules.put(parsed.name, parsed);
+        }
+    }
+
+
+    public ParsedRule getRule(String name) {
+        return rules.get(name);
+    }
+
+    public static Collection<ParsedRule<?>> getRules() {
+        CarpetSettings.LOG.error("grabbing rules");
+        List<ParsedRule<?>> r = rules.values().stream().sorted().collect(Collectors.toList());
+        CarpetSettings.LOG.error("Got: "+r.size()+" rules");
+        return r;
+    }
+
+    public Collection<ParsedRule<?>> findStartupOverrides()
+    {
+        Set<String> defaults = readSettingsFromConf().getLeft().keySet();
+        return rules.values().stream().filter(r -> defaults.contains(r.name)).
+                sorted().collect(Collectors.toList());
+    }
+
+
+    public Collection<ParsedRule<?>> getNonDefault() {
+        return rules.values().stream().filter(r -> !r.isDefault()).sorted().collect(Collectors.toList());
+    }
+
+    private File getFile() {
+        return server.getLevelStorage().resolveFile(server.getLevelName(), "carpet.conf");
+    }
+
+    public void disableBooleanFromCategory(RuleCategory category) {
+        for (ParsedRule<?> rule : rules.values()) {
+            if (rule.type != boolean.class || !rule.categories.contains(category)) continue;
+            ((ParsedRule<Boolean>) rule).set(server.getCommandSource(), false, "false");
+        }
+    }
+
+
+
+    private void writeSettingsToConf(Map<String, String> values)
+    {
+        if (locked) return;
+        try
+        {
+            FileWriter fw  = new FileWriter(getFile());
+            for (String key: values.keySet())
+            {
+                fw.write(key+" "+values.get(key)+"\n");
+            }
+            fw.close();
+        }
+        catch (IOException e)
+        {
+            e.printStackTrace();
+            LOG.error("[CM]: failed write the carpet.conf");
+        }
+        ///todo is it really needed? resendCommandTree();
+    }
+
+    public void notifyPlayersCommandsChanged()
+    {
+        if (server.getPlayerManager() == null)
+        {
+            return;
+        }
+        for (ServerPlayerEntity entityplayermp : server.getPlayerManager().getPlayerList())
+        {
+            server.getCommandManager().sendCommandTree(entityplayermp);
+        }
+    }
+
+    private void loadConfigurationFromConf()
+    {
+        for (ParsedRule<?> rule : rules.values()) rule.resetToDefault(server.getCommandSource());
+        Pair<Map<String, String>,Boolean> conf = readSettingsFromConf();
+        locked = false;
+        if (conf.getRight())
+        {
+            LOG.info("[CM]: Carpet Mod is locked by the administrator");
+            disableBooleanFromCategory(RuleCategory.COMMANDS);
+        }
+        for (String key: conf.getLeft().keySet())
+        {
+            if (rules.get(key).set(server.getCommandSource(), conf.getLeft().get(key)) != null)
+                LOG.info("[CM]: loaded setting "+key+" as "+conf.getLeft().get(key)+" from carpet.conf");
+        }
+        locked = conf.getRight();
+    }
+
+
+    public Pair<Map<String, String>,Boolean> readSettingsFromConf()
+    {
+        try
+        {
+            BufferedReader reader = new BufferedReader(new FileReader(getFile()));
+            String line = "";
+            boolean confLocked = false;
+            Map<String,String> result = new HashMap<String, String>();
+            while ((line = reader.readLine()) != null)
+            {
+                line = line.replaceAll("\\r|\\n", "");
+                if ("locked".equalsIgnoreCase(line))
+                {
+                    confLocked = true;
+                }
+                String[] fields = line.split("\\s+",2);
+                if (fields.length > 1)
+                {
+                    if (!rules.containsKey(fields[0]))
+                    {
+                        LOG.error("[CM]: Setting " + fields[0] + " is not a valid - ignoring...");
+                        continue;
+                    }
+                    ParsedRule rule = rules.get(fields[0]);
+
+
+
+                    if (!(rule.options.contains(fields[1])) && rule.isStrict)
+                    {
+                        LOG.error("[CM]: The value of " + fields[1] + " for " + fields[0] + " is not valid - ignoring...");
+                        continue;
+                    }
+                    result.put(fields[0],fields[1]);
+
+                }
+            }
+            reader.close();
+            return Pair.of(result, confLocked);
+        }
+        catch(FileNotFoundException e)
+        {
+            return Pair.of(new HashMap<>(), false);
+        }
+        catch (IOException e)
+        {
+            e.printStackTrace();
+            return Pair.of(new HashMap<>(), false);
+        }
+    }
+
+    // stores different defaults in the file
+    public boolean setDefaultRule(ServerCommandSource source, String settingName, String stringValue)
+    {
+        if (locked) return false;
+        if (rules.containsKey(settingName))
+        {
+            Pair<Map<String, String>,Boolean> conf = readSettingsFromConf();
+            conf.getLeft().put(settingName, stringValue);
+            writeSettingsToConf(conf.getLeft()); // this may feels weird, but if conf
+            // is locked, it will never reach this point.
+            rules.get(settingName).set(source,stringValue);
+            return true;
+        }
+        return false;
+    }
+    // removes overrides of the default values in the file
+    public boolean removeDefaultRule(ServerCommandSource source, String settingName)
+    {
+        if (locked) return false;
+        if (rules.containsKey(settingName))
+        {
+            Pair<Map<String, String>,Boolean> conf = readSettingsFromConf();
+            conf.getLeft().remove(settingName);
+            writeSettingsToConf(conf.getLeft());
+            rules.get(settingName).resetToDefault(source);
+            return true;
+        }
+        return false;
+    }
+
+    public Collection<ParsedRule<?>> getRulesMatching(Predicate<ParsedRule<?>> predicate) {
+        return rules.values().stream().filter(predicate).collect(ImmutableList.toImmutableList());
+    }
+
+    public Collection<ParsedRule<?>> getRulesMatching(String search) {
+        String lcSearch = search.toLowerCase(Locale.ROOT);
+        return getRulesMatching(rule -> {
+            if (rule.name.toLowerCase(Locale.ROOT).contains(lcSearch)) return true;
+            for (RuleCategory c : rule.categories) if (c.lowerCase.equals(search)) return true;
+            return false;
+        });
+    }
+}

src/main/java/carpet/settings/Validator.java

@@ -0,0 +1,63 @@
+package carpet.settings;
+
+import carpet.CarpetServer;
+import carpet.utils.Messenger;
+import net.minecraft.server.command.ServerCommandSource;
+
+import java.util.Locale;
+
+public abstract class Validator<T> {
+    /**
+     * Validate the new value of a rule
+     * @return true if valid, false if new rule invalid.
+     */
+    abstract boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string);
+
+
+    public static class POSITIVE_NUMBER<T extends Number> extends Validator<T> {
+        @Override
+        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+            return newValue.doubleValue() > 0;
+        }
+    }
+
+    public static class _COMMAND<T> extends Validator<T> {
+        @Override
+        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+            if (CarpetServer.settingsManager != null)
+                CarpetServer.settingsManager.notifyPlayersCommandsChanged();
+            return true;
+        }
+    }
+
+    public static class WIP<T> extends Validator<T> {
+        @Override
+        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+            if (source != null)
+                try
+                {
+                    Messenger.m(source, "r Work in progress - limited or no functionality available for "+currentRule.name);
+                }
+                catch (NullPointerException ignored) { }
+            return true;
+        }
+    }
+    public static class _STRICT<T> extends Validator<T> {
+        @Override
+        public boolean validate(ServerCommandSource source, ParsedRule<T> currentRule, T newValue, String string) {
+            if (!currentRule.options.contains(string.toLowerCase(Locale.ROOT)))
+            {
+                if (source != null)
+                    try
+                    {
+                        Messenger.m(source, "r Valid options: " + currentRule.options.toString());
+                    }
+                    catch (NullPointerException ignored)
+                    {
+                    }
+                return false;
+            }
+            return true;
+        }
+    }
+}