!source: don't show source of messages you don't have access to; allow mods to use the command by default

backend/src/commandTypes.ts

@@ -1,7 +1,24 @@
-import { convertDelayStringToMS, disableCodeBlocks, resolveMember, resolveUser, UnknownUser } from "./utils";
-import { GuildChannel, Member, User } from "eris";
+import {
+  convertDelayStringToMS,
+  disableCodeBlocks,
+  disableInlineCode,
+  isSnowflake,
+  resolveMember,
+  resolveUser,
+  UnknownUser,
+} from "./utils";
+import { GuildChannel, Member, TextChannel, User } from "eris";
 import { baseTypeConverters, baseTypeHelpers, CommandContext, TypeConversionError } from "knub";
 import { createTypeHelper } from "knub-command-manager";
+import { getChannelIdFromMessageId } from "./data/getChannelIdFromMessageId";
+
+export interface MessageTarget {
+  channel: TextChannel;
+  messageId: string;
+}
+
+const channelAndMessageIdRegex = /^(\d+)[\-\/](\d+)$/;
+const messageLinkRegex = /^https:\/\/(?:\w+\.)?discord(?:app)?\.com\/channels\/\d+\/(\d+)\/(\d+)$/i;
 
 export const commandTypes = {
   ...baseTypeConverters,
@@ -42,6 +59,52 @@ export const commandTypes = {
     }
     return result;
   },
+
+  async messageTarget(value: string, context: CommandContext<any>) {
+    value = String(value).trim();
+
+    const result = await (async () => {
+      if (isSnowflake(value)) {
+        const channelId = await getChannelIdFromMessageId(value);
+        if (!channelId) {
+          throw new TypeConversionError(`Could not find channel for message ID \`${disableInlineCode(value)}\``);
+        }
+
+        return {
+          channelId,
+          messageId: value,
+        };
+      }
+
+      const channelAndMessageIdMatch = value.match(channelAndMessageIdRegex);
+      if (channelAndMessageIdMatch) {
+        return {
+          channelId: channelAndMessageIdMatch[1],
+          messageId: channelAndMessageIdMatch[2],
+        };
+      }
+
+      const messageLinkMatch = value.match(messageLinkRegex);
+      if (messageLinkMatch) {
+        return {
+          channelId: messageLinkMatch[1],
+          messageId: messageLinkMatch[2],
+        };
+      }
+
+      throw new TypeConversionError(`Invalid message ID \`${disableInlineCode(value)}\``);
+    })();
+
+    const channel = context.pluginData.guild.channels.get(result.channelId);
+    if (!channel || !(channel instanceof TextChannel)) {
+      throw new TypeConversionError(`Invalid channel ID \`${disableInlineCode(result.channelId)}\``);
+    }
+
+    return {
+      channel,
+      messageId: result.messageId,
+    };
+  },
 };
 
 export const commandTypeHelpers = {
@@ -51,4 +114,5 @@ export const commandTypeHelpers = {
   resolvedUser: createTypeHelper<Promise<User>>(commandTypes.resolvedUser),
   resolvedUserLoose: createTypeHelper<Promise<User | UnknownUser>>(commandTypes.resolvedUserLoose),
   resolvedMember: createTypeHelper<Promise<Member | null>>(commandTypes.resolvedMember),
+  messageTarget: createTypeHelper<Promise<MessageTarget>>(commandTypes.messageTarget),
 };