Start implementing bot info command

src/main/java/wtf/beatrice/hidekobot/commands/slash/BotInfoCommand.java

@@ -0,0 +1,85 @@
+package wtf.beatrice.hidekobot.commands.slash;
+
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.events.interaction.command.SlashCommandInteractionEvent;
+import net.dv8tion.jda.api.interactions.commands.Command;
+import org.jetbrains.annotations.NotNull;
+import wtf.beatrice.hidekobot.Configuration;
+import wtf.beatrice.hidekobot.HidekoBot;
+
+import java.lang.management.ManagementFactory;
+import java.text.DecimalFormat;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.time.temporal.ChronoUnit;
+import java.util.List;
+
+public class BotInfoCommand
+{
+
+    public void runSlashCommand(@NotNull SlashCommandInteractionEvent event)
+    {
+        // defer reply because this might take a moment
+        event.deferReply().queue();
+
+        List<Command> registeredCommands = Configuration.getRegisteredCommands();
+
+        EmbedBuilder embedBuilder = new EmbedBuilder();
+
+        // embed processing
+        {
+            embedBuilder.setColor(Configuration.getBotColor());
+            embedBuilder.setTitle(Configuration.getBotName());
+
+            // thumbnail
+            String botAvatarUrl = HidekoBot.getAPI().getSelfUser().getAvatarUrl();
+            if(botAvatarUrl != null) embedBuilder.setThumbnail(botAvatarUrl);
+
+            // commands list field
+            StringBuilder commandsListBuilder = new StringBuilder();
+            commandsListBuilder.append(registeredCommands.size()).append( " total - ");
+            for(int i = 0; i < registeredCommands.size(); i++)
+            {
+                Command cmd = registeredCommands.get(i);
+                commandsListBuilder.append("`" + cmd.getName() + "`");
+
+                if(i + 1 != registeredCommands.size()) // don't add comma in last iteration
+                {
+                    commandsListBuilder.append(", ");
+                }
+
+            }
+            embedBuilder.addField("Commands", commandsListBuilder.toString(), false);
+
+            // version field
+            embedBuilder.addField("Version", "v" + Configuration.getBotVersion(), true);
+
+            // jvm version field
+            String jvmVersion = ManagementFactory.getRuntimeMXBean().getVmVersion();
+            embedBuilder.addField("JVM Version", "v" + jvmVersion, true);
+
+            // used ram field
+            long usedRamBytes = (Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory());
+            double usedRamMB = usedRamBytes / 1024.0 / 1024.0; // bytes -> kB -> MB
+            DecimalFormat ramMBFormatter = new DecimalFormat("#.##");
+            embedBuilder.addField("RAM Usage", ramMBFormatter.format(usedRamMB) + " MB", true);
+
+            // author field
+            String authorMention = "<@" + Configuration.getBotOwnerId() + ">";
+            embedBuilder.addField("Author", authorMention, true);
+
+            // uptime field
+            LocalDateTime now = LocalDateTime.now();
+            long uptimeSeconds = ChronoUnit.SECONDS.between(Configuration.getStartupTime(), now);
+            Duration uptime = Duration.ofSeconds(uptimeSeconds);
+            uptime.toDaysPart() // todo
+            embedBuilder.addField("Uptime", "seconds: " + uptime, true);
+
+
+        }
+
+        event.getHook().editOriginalEmbeds(embedBuilder.build()).queue();
+
+
+    }
+}