Add !invite utility command

backend/src/plugins/Censor/util/applyFiltersToMsg.ts

@@ -1,9 +1,16 @@
 import { PluginData } from "knub";
 import { CensorPluginType } from "../types";
 import { SavedMessage } from "src/data/entities/SavedMessage";
-import { Embed, GuildInvite } from "eris";
+import { AnyInvite, Embed, GuildInvite } from "eris";
 import { ZalgoRegex } from "src/data/Zalgo";
-import { getInviteCodesInString, getUrlsInString, resolveMember, resolveInvite } from "src/utils";
+import {
+  getInviteCodesInString,
+  getUrlsInString,
+  resolveMember,
+  resolveInvite,
+  isGuildInvite,
+  isRESTGuildInvite,
+} from "src/utils";
 import cloneDeep from "lodash.clonedeep";
 import { censorMessage } from "./censorMessage";
 import escapeStringRegexp from "escape-string-regexp";
@@ -52,7 +59,7 @@ export async function applyFiltersToMsg(
 
     const inviteCodes = getInviteCodesInString(messageContent);
 
-    const invites: Array<GuildInvite | null> = await Promise.all(
+    const invites: Array<AnyInvite | null> = await Promise.all(
       inviteCodes.map(code => resolveInvite(pluginData.client, code)),
     );
 
@@ -63,27 +70,29 @@ export async function applyFiltersToMsg(
         return true;
       }
 
-      if (!invite.guild && !allowGroupDMInvites) {
+      if (!isGuildInvite(invite) && !allowGroupDMInvites) {
         censorMessage(pluginData, savedMessage, `group dm invites are not allowed`);
         return true;
       }
 
-      if (inviteGuildWhitelist && !inviteGuildWhitelist.includes(invite.guild.id)) {
-        censorMessage(
-          pluginData,
-          savedMessage,
-          `invite guild (**${invite.guild.name}** \`${invite.guild.id}\`) not found in whitelist`,
-        );
-        return true;
-      }
+      if (isRESTGuildInvite(invite)) {
+        if (inviteGuildWhitelist && !inviteGuildWhitelist.includes(invite.guild.id)) {
+          censorMessage(
+            pluginData,
+            savedMessage,
+            `invite guild (**${invite.guild.name}** \`${invite.guild.id}\`) not found in whitelist`,
+          );
+          return true;
+        }
 
-      if (inviteGuildBlacklist && inviteGuildBlacklist.includes(invite.guild.id)) {
-        censorMessage(
-          pluginData,
-          savedMessage,
-          `invite guild (**${invite.guild.name}** \`${invite.guild.id}\`) found in blacklist`,
-        );
-        return true;
+        if (inviteGuildBlacklist && inviteGuildBlacklist.includes(invite.guild.id)) {
+          censorMessage(
+            pluginData,
+            savedMessage,
+            `invite guild (**${invite.guild.name}** \`${invite.guild.id}\`) found in blacklist`,
+          );
+          return true;
+        }
       }
 
       if (inviteCodeWhitelist && !inviteCodeWhitelist.includes(invite.code)) {

backend/src/plugins/Utility/UtilityPlugin.ts

@@ -27,6 +27,7 @@ import { JumboCmd } from "./commands/JumboCmd";
 import { AvatarCmd } from "./commands/AvatarCmd";
 import { CleanCmd } from "./commands/CleanCmd";
 import { Message } from "eris";
+import { InviteInfoCmd } from "./commands/InviteInfoCmd";
 
 const defaultOptions: PluginOptions<UtilityPluginType> = {
   config: {
@@ -36,6 +37,7 @@ const defaultOptions: PluginOptions<UtilityPluginType> = {
     can_clean: false,
     can_info: false,
     can_server: false,
+    can_invite: false,
     can_reload_guild: false,
     can_nickname: false,
     can_ping: false,
@@ -59,6 +61,7 @@ const defaultOptions: PluginOptions<UtilityPluginType> = {
         can_clean: true,
         can_info: true,
         can_server: true,
+        can_invite: true,
         can_nickname: true,
         can_vcmove: true,
         can_help: true,
@@ -108,6 +111,7 @@ export const UtilityPlugin = zeppelinPlugin<UtilityPluginType>()("utility", {
     JumboCmd,
     AvatarCmd,
     CleanCmd,
+    InviteInfoCmd,
   ],
 
   onLoad(pluginData) {

backend/src/plugins/Utility/commands/InviteInfoCmd.ts

@@ -0,0 +1,27 @@
+import { utilityCmd } from "../types";
+import { commandTypeHelpers as ct } from "../../../commandTypes";
+import { sendErrorMessage } from "../../../pluginUtils";
+import { getInviteInfoEmbed } from "../functions/getInviteInfoEmbed";
+import { parseInviteCodeInput } from "../../../utils";
+
+export const InviteInfoCmd = utilityCmd({
+  trigger: ["invite", "inviteinfo"],
+  description: "Show information about an invite",
+  usage: "!invite overwatch",
+  permission: "can_invite",
+
+  signature: {
+    inviteCode: ct.string({ required: false }),
+  },
+
+  async run({ message, args, pluginData }) {
+    const inviteCode = parseInviteCodeInput(args.inviteCode);
+    const embed = await getInviteInfoEmbed(pluginData, inviteCode);
+    if (!embed) {
+      sendErrorMessage(pluginData, message.channel, "Unknown invite");
+      return;
+    }
+
+    message.channel.createMessage({ embed });
+  },
+});

backend/src/plugins/Utility/functions/getInviteInfoEmbed.ts

@@ -0,0 +1,94 @@
+import { PluginData } from "knub";
+import { UtilityPluginType } from "../types";
+import { BaseInvite, Constants, EmbedOptions, RESTChannelInvite, RESTPrivateInvite } from "eris";
+import { snowflakeToTimestamp } from "../../../utils/snowflakeToTimestamp";
+import moment from "moment-timezone";
+import humanizeDuration from "humanize-duration";
+import { emptyEmbedValue, formatNumber, isRESTGroupDMInvite, isRESTGuildInvite, resolveInvite } from "../../../utils";
+
+export async function getInviteInfoEmbed(
+  pluginData: PluginData<UtilityPluginType>,
+  inviteCode: string,
+): Promise<EmbedOptions | null> {
+  const invite = await resolveInvite(pluginData.client, inviteCode, true);
+  if (!invite) {
+    return null;
+  }
+
+  if (isRESTGuildInvite(invite)) {
+    const embed: EmbedOptions = {
+      fields: [],
+    };
+
+    if (invite.guild.icon) {
+      embed.thumbnail = {
+        url: `https://cdn.discordapp.com/icons/${invite.guild.id}/${invite.guild.icon}.png?size=256`,
+      };
+    }
+
+    embed.title = `Server Invite - ${invite.guild.name}`;
+    embed.url = `https://discord.gg/${invite.code}`;
+
+    embed.fields.push({
+      name: "Server ID",
+      value: `\`${invite.guild.id}\``,
+      inline: true,
+    });
+
+    embed.fields.push({
+      name: "Channel",
+      value:
+        invite.channel.type === Constants.ChannelTypes.GUILD_VOICE
+          ? `🔉 ${invite.channel.name}\n\`${invite.channel.id}\``
+          : `#${invite.channel.name}\n\`${invite.channel.id}\``,
+    });
+
+    const createdAtTimestamp = snowflakeToTimestamp(invite.guild.id);
+    const createdAt = moment(createdAtTimestamp, "x");
+    const serverAge = humanizeDuration(Date.now() - createdAtTimestamp, {
+      largest: 2,
+      round: true,
+    });
+
+    embed.fields.push({
+      name: "Server age",
+      value: serverAge,
+    });
+
+    embed.fields.push({
+      name: "Members",
+      value: `**${formatNumber(invite.memberCount)}** (${formatNumber(invite.presenceCount)} online)`,
+      inline: true,
+    });
+
+    return embed;
+  }
+
+  if (isRESTGroupDMInvite(invite)) {
+    const embed: EmbedOptions = {
+      fields: [],
+    };
+
+    if (invite.channel.icon) {
+      embed.thumbnail = {
+        url: `https://cdn.discordapp.com/channel-icons/${invite.channel.id}/${invite.channel.icon}.png?size=256`,
+      };
+    }
+
+    embed.title = invite.channel.name ? `Group DM Invite - ${invite.channel.name}` : `Group DM Invite`;
+
+    embed.fields.push({
+      name: "Channel ID",
+      value: `\`${invite.channel.id}\``,
+    });
+
+    embed.fields.push({
+      name: "Members",
+      value: formatNumber((invite as any).memberCount),
+    });
+
+    return embed;
+  }
+
+  return null;
+}

backend/src/plugins/Utility/types.ts

@@ -13,6 +13,7 @@ export const ConfigSchema = t.type({
   can_clean: t.boolean,
   can_info: t.boolean,
   can_server: t.boolean,
+  can_invite: t.boolean,
   can_reload_guild: t.boolean,
   can_nickname: t.boolean,
   can_ping: t.boolean,

backend/src/utils.ts

@@ -1,6 +1,7 @@
 import {
   AnyInvite,
   Attachment,
+  BaseInvite,
   ChannelInvite,
   Client,
   Embed,
@@ -15,6 +16,8 @@ import {
   Message,
   MessageContent,
   PossiblyUncachedMessage,
+  RESTChannelInvite,
+  RESTPrivateInvite,
   TextableChannel,
   TextChannel,
   User,
@@ -450,6 +453,14 @@ export function getUrlsInString(str: string, onlyUnique = false): MatchedURL[] {
   }, []);
 }
 
+export function parseInviteCodeInput(str: string): string {
+  if (str.match(/^[a-z0-9]{6,}$/i)) {
+    return str;
+  }
+
+  return getInviteCodesInString(str)[0];
+}
+
 export function getInviteCodesInString(str: string): string[] {
   const inviteCodeRegex = /(?:discord.gg|discordapp.com\/invite|discord.com\/invite)\/([a-z0-9]+)/gi;
   return Array.from(str.matchAll(inviteCodeRegex)).map(m => m[1]);
@@ -1064,13 +1075,15 @@ export async function resolveRoleId(bot: Client, guildId: string, value: string)
 
 const inviteCache = new SimpleCache<Promise<ChannelInvite>>(10 * MINUTES, 200);
 
-export async function resolveInvite(client: Client, code: string): Promise<ChannelInvite | null> {
-  if (inviteCache.has(code)) {
-    return inviteCache.get(code);
+export async function resolveInvite(client: Client, code: string, withCounts?: boolean): Promise<AnyInvite | null> {
+  const key = `${code}:${withCounts ? 1 : 0}`;
+
+  if (inviteCache.has(key)) {
+    return inviteCache.get(key);
   }
 
-  const promise = client.getInvite(code).catch(() => null);
-  inviteCache.set(code, promise);
+  const promise = client.getInvite(code, withCounts).catch(() => null);
+  inviteCache.set(key, promise);
 
   return promise;
 }
@@ -1229,6 +1242,14 @@ export function isGuildInvite(invite: AnyInvite): invite is GuildInvite {
   return (invite as GuildInvite).guild != null;
 }
 
+export function isRESTGuildInvite(invite: BaseInvite): invite is RESTChannelInvite {
+  return (invite as any).guild != null;
+}
+
+export function isRESTGroupDMInvite(invite: BaseInvite): invite is RESTPrivateInvite {
+  return (invite as any).guild == null && (invite as any).channel != null;
+}
+
 export function asyncMap<T, R>(arr: T[], fn: (item: T) => Promise<R>): Promise<R[]> {
   return Promise.all(arr.map((item, index) => fn(item)));
 }

backend/src/utils/snowflakeToTimestamp.ts

@@ -0,0 +1,7 @@
+/**
+ * @return Unix timestamp in milliseconds
+ */
+export function snowflakeToTimestamp(snowflake: string) {
+  // https://discord.com/developers/docs/reference#snowflakes-snowflake-id-format-structure-left-to-right
+  return Number(BigInt(snowflake) >> 22n) + 1420070400000;
+}