Add message when discord bot is missing permissions (#6228)

Closes #5450

Author: JRoy

Essentials/src/main/resources/messages.properties

@@ -276,6 +276,7 @@ discordErrorLoggerNoPerms=Discord console logger has been disabled due to insuff
 discordErrorNoGuild=Invalid or missing server ID\! Please follow the tutorial in the config in order to setup the plugin.
 discordErrorNoGuildSize=Your bot is not in any servers\! Please follow the tutorial in the config in order to setup the plugin.
 discordErrorNoPerms=Your bot cannot see or talk in any channel\! Please make sure your bot has read and write permissions in all channels you wish to use.
+discordErrorInvalidPerms=Your bot was not set up with the required permissions\! Missing permissions are\: {0}.
 discordErrorNoPrimary=You did not define a primary channel or your defined primary channel is invalid. Falling back to the default channel\: \#{0}.
 discordErrorNoPrimaryPerms=Your bot cannot speak in your primary channel, \#{0}. Please make sure your bot has read and write permissions in all channels you wish to use.
 discordErrorNoToken=No token provided\! Please follow the tutorial in the config in order to setup the plugin.

EssentialsDiscord/build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 dependencies {
     compileOnly project(':EssentialsX')
-    implementation('net.dv8tion:JDA:5.3.0') {
+    implementation('net.dv8tion:JDA:5.6.1') {
         exclude(module: 'opus-java')
     }
     implementation 'com.github.MinnDevelopment:emoji-java:v6.1.0'

EssentialsDiscord/src/main/java/net/essentialsx/discord/JDADiscordService.java

@@ -8,10 +8,12 @@
 import com.earth2me.essentials.utils.FormatUtil;
 import com.earth2me.essentials.utils.NumberUtil;
 import com.earth2me.essentials.utils.VersionUtil;
+import com.google.common.collect.ImmutableList;
 import com.neovisionaries.ws.client.ProxySettings;
 import com.neovisionaries.ws.client.WebSocketFactory;
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.JDABuilder;
+import net.dv8tion.jda.api.Permission;
 import net.dv8tion.jda.api.entities.Guild;
 import net.dv8tion.jda.api.entities.Role;
 import net.dv8tion.jda.api.entities.Webhook;
@@ -200,6 +202,17 @@ public void startup() throws LoginException, InterruptedException {
             throw new IllegalArgumentException(tlLiteral("discordErrorNoGuild"));
         }
 
+        final Collection<Permission> requiredPermissions = ImmutableList.of(Permission.MANAGE_WEBHOOKS, Permission.MANAGE_ROLES, Permission.NICKNAME_MANAGE, Permission.VIEW_CHANNEL, Permission.MESSAGE_SEND, Permission.MESSAGE_EMBED_LINKS);
+        final String[] missingPermissions = requiredPermissions.stream()
+                .filter(permission -> !guild.getSelfMember().hasPermission(permission))
+                .map(Permission::getName)
+                .toArray(String[]::new);
+
+        if (missingPermissions.length > 0) {
+            invalidStartup = true;
+            throw new IllegalArgumentException(tlLiteral("discordErrorInvalidPerms", String.join(", ", missingPermissions)));
+        }
+
         interactionController = new InteractionControllerImpl(this);
         // Each will throw an exception if disabled
         try {