Add the /math command with Javaluator API

Author: TechnoVisionDev

pom.xml

@@ -63,6 +63,12 @@
             <artifactId>okhttp</artifactId>
             <version>4.9.3</version>
         </dependency>
+        <!-- http://javaluator.sourceforge.net/en/home/ -->
+        <dependency>
+            <groupId>com.fathzer</groupId>
+            <artifactId>javaluator</artifactId>
+            <version>3.0.3</version>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/technobot/commands/CommandRegistry.java

@@ -134,6 +134,7 @@ public CommandRegistry(TechnoBot bot) {
                 new PollCommand(bot),
                 new InviteCommand(bot),
                 new PremiumCommand(bot),
+                new MathCommand(bot),
                 new HelpCommand(bot) // The 'help' command MUST come last!!!
         );
     }

src/main/java/technobot/commands/utility/MathCommand.java

@@ -0,0 +1,47 @@
+package technobot.commands.utility;
+
+import com.fathzer.soft.javaluator.DoubleEvaluator;
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.events.interaction.command.SlashCommandInteractionEvent;
+import net.dv8tion.jda.api.interactions.commands.OptionType;
+import net.dv8tion.jda.api.interactions.commands.build.OptionData;
+import technobot.TechnoBot;
+import technobot.commands.Category;
+import technobot.commands.Command;
+import technobot.util.embeds.EmbedColor;
+import technobot.util.embeds.EmbedUtils;
+
+import java.text.DecimalFormat;
+
+/**
+ * Solves expressions like a calculator.
+ *
+ * @author TechnoVision
+ */
+public class MathCommand extends Command {
+
+    private static final DecimalFormat FORMATTER = new DecimalFormat("#,###.####");
+
+    public MathCommand(TechnoBot bot) {
+        super(bot);
+        this.name = "math";
+        this.description = "Calculate a mathematical expression.";
+        this.category = Category.UTILITY;
+        this.args.add(new OptionData(OptionType.STRING, "expression", "The math expression to solve.", true));
+    }
+
+    @Override
+    public void execute(SlashCommandInteractionEvent event) {
+        String expression = event.getOption("expression").getAsString();
+        try {
+            Double result = new DoubleEvaluator().evaluate(expression);
+            EmbedBuilder embed = new EmbedBuilder()
+                    .setColor(EmbedColor.DEFAULT.color)
+                    .addField("Expression", "`"+expression+"`", false)
+                    .addField("Result", FORMATTER.format(result), false);
+            event.replyEmbeds(embed.build()).queue();
+        } catch (IllegalArgumentException e) {
+            event.replyEmbeds(EmbedUtils.createError("That is not a valid math expression! Example: `(2^3-1)*sin(pi/4)/ln(pi^2)`")).setEphemeral(true).queue();
+        }
+    }
+}

src/main/java/technobot/commands/utility/PremiumCommand.java

@@ -7,7 +7,6 @@
 import technobot.commands.Category;
 import technobot.commands.Command;
 import technobot.util.embeds.EmbedColor;
-import technobot.util.embeds.EmbedUtils;
 
 /**
  * Creates button links to the Patreon to buy premium.