Merge pull request #49 from hspsh/libre-alternatives

Add a plugin which rewrites Twitter links to nitter.net links

.eslintrc.js

@@ -16,4 +16,14 @@ module.exports = {
     'plugins': [
         '@typescript-eslint'
     ],
+    'rules': {
+        '@typescript-eslint/no-unused-vars': [
+            'warn',
+            {
+                argsIgnorePattern: '^_',
+                varsIgnorePattern: '^_',
+                caughtErrorsIgnorePattern: '^_',
+            },
+        ],
+    }
 };

lib/plugins/libreLinks/plugin.ts

@@ -0,0 +1,85 @@
+import { Message } from 'discord.js'
+import { MessageHandler, Plugin } from '../pluginManager'
+
+// https://stackoverflow.com/a/3809435/18140793
+const URL_REGEX =
+    /https?:\/\/(www\.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_+.~#?&//=]*)/g
+
+const getUrls = (str: string): string[] => {
+    const matches = Array.from(str.matchAll(URL_REGEX))
+    const urls = matches.map((x) => x[0])
+    return urls
+}
+
+const isUnsignedInt = (num: string): boolean => {
+    for (const char of num) {
+        if (!(char >= '0' && char <= '9')) {
+            return false
+        }
+    }
+
+    return true
+}
+
+const getNitterLink = (link: string): string | undefined => {
+    const url = new URL(link)
+
+    if (url.host != 'twitter.com') {
+        return
+    }
+
+    const [_, ...pathSegments] = url.pathname.split('/')
+    const isProfile = pathSegments.length == 1
+    const isStatus =
+        pathSegments.length == 3 &&
+        pathSegments[1] == 'status' &&
+        isUnsignedInt(pathSegments[2])
+
+    if (!isProfile && !isStatus) {
+        return
+    }
+
+    url.search = ''
+    url.host = 'nitter.net'
+    url.protocol = 'https'
+
+    return url.toString()
+}
+
+const replaceUrls = (urls: string[]): string[] => {
+    const replaced: string[] = []
+
+    urls.forEach((url) => {
+        const transformed = getNitterLink(url)
+        if (transformed !== undefined) {
+            replaced.push(transformed)
+        }
+    })
+
+    return replaced
+}
+
+const messageHandlers: MessageHandler[] = [
+    {
+        predicate: async (_: Message) => true,
+        action: async (msg: Message): Promise<void> => {
+            const urls = getUrls(msg.content)
+            const replaced = replaceUrls(urls)
+
+            if (replaced.length == 0) {
+                return
+            }
+
+            const response = replaced.join('\n')
+            await msg.channel.send(response)
+        },
+    },
+]
+
+const LibreLinksPlugin: Plugin = {
+    name: 'libre-links',
+    messageHandlers,
+    commands: [],
+}
+
+export default LibreLinksPlugin

lib/plugins/pluginManager.ts

@@ -7,13 +7,15 @@ import config from '../config'
 
 import whoisPlugin from './whois/plugin'
 import { JudgementPluginFactory } from './rel/plugin'
+import LibreLinksPlugin from './libreLinks/plugin'
 
 export type Command = {
     name: string
     description: string
     handle: (interaction: CommandInteraction) => Promise<void>
 }
 
+// TODO(LiquidLemon): replace with simple middleware to prevent work duplication
 export type MessageHandler = {
     predicate: (message: Message) => Promise<boolean>
     action: (message: Message) => Promise<void>
@@ -87,12 +89,17 @@ export default class PluginManager {
     }
 
     public async handleMessage(interaction: Message): Promise<void> {
+        if (interaction.author.id == interaction.client.user?.id) {
+            return
+        }
+
         const logContext = {
             messageContent: interaction.content,
             user: `${interaction.author.username}#${interaction.author.discriminator}`,
             userId: interaction.author.id,
         }
 
+        // TODO(LiquidLemon): simplify this monstrosity
         const messageHandler = (
             await Promise.all(
                 this.plugins
@@ -111,10 +118,8 @@ export default class PluginManager {
             return
         }
 
-        logger.info('Handling message.', logContext)
-
         try {
-            logger.info('Handling message.', logContext)
+            logger.debug('Handling message.', logContext)
             await messageHandler(interaction)
         } catch (error) {
             logger.error(
@@ -131,6 +136,7 @@ export default class PluginManager {
             await JudgementPluginFactory.createPlugin(
                 config.env.REL_DB_PATH || './sqlite.db'
             ),
+            LibreLinksPlugin,
         ])
     }
 }

lib/plugins/whois/plugin.ts

@@ -1,4 +1,9 @@
-import { CommandInteraction, GuildMember, Message, TextChannel } from 'discord.js'
+import {
+    CommandInteraction,
+    GuildMember,
+    Message,
+    TextChannel,
+} from 'discord.js'
 
 import { Plugin, Command, MessageHandler } from '../pluginManager'
 import api from './api'