[refactor] try to generate general structures

src/main/java/net/saltymc/eaa/handler/commands/Command.java

@@ -0,0 +1,14 @@
+package net.saltymc.eaa.handler.commands;
+
+import net.fabricmc.fabric.api.client.command.v1.FabricClientCommandSource;
+
+public interface Command {
+
+    boolean run(final FabricClientCommandSource cs, String[] args);
+
+    /**
+     * should message get intercepted and not send to Server?
+     */
+    boolean intercept();
+
+}

src/main/java/net/saltymc/eaa/handler/commands/EaaCommand.java

@@ -0,0 +1,31 @@
+package net.saltymc.eaa.handler.commands;
+
+import net.fabricmc.fabric.api.client.command.v1.FabricClientCommandSource;
+import net.minecraft.text.Text;
+
+public class EaaCommand implements Command {
+
+    private static final String COMMAND = "echo";
+    private static final boolean INTERCEPT = true;
+
+    @Override
+    public boolean run( final FabricClientCommandSource cs, String[] args) {
+        if (!args[0].equalsIgnoreCase(COMMAND)) {
+            return false;
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (String arg : args)
+            sb.append(arg);
+
+        cs.sendFeedback(Text.of(sb.toString().replaceFirst(args[0], "")));
+
+
+        return true;
+    }
+
+    @Override
+    public boolean intercept() {
+        return INTERCEPT;
+    }
+}