feat: add captcha feature

.github/workflows/main.yml

@@ -15,10 +15,10 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v3
 
-      - name: Use Node 19 
+      - name: Use Node 20 
         uses: actions/setup-node@v1
         with:
-          node-version: 19 
+          node-version: 20 
 
       - name: Install dependencies 
         run: yarn 

.github/workflows/pr.yml

@@ -8,10 +8,10 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v2
 
-      - name: Use Node 19 
+      - name: Use Node 20
         uses: actions/setup-node@v1
         with:
-          node-version: 19 
+          node-version: 20
 
       - name: Install dependencies 
         run: yarn 

Dockerfile

@@ -1,11 +1,11 @@
-FROM node:19-alpine AS builder
+FROM node:20-alpine AS builder
 WORKDIR /app
 COPY package.json yarn.lock ./
 RUN yarn
 COPY . .
 RUN yarn build
 
-FROM node:19-alpine
+FROM node:20-alpine
 WORKDIR /app
 COPY --from=builder /app/package.json ./package.json
 COPY --from=builder /app/node_modules ./node_modules

README.md

@@ -64,6 +64,11 @@ The bot replies in English by default. You can change the language using the `/s
  - [x] Set Group Language:
     - [x] `/set_language en`
     - [x] `/set_language ptbr`
+ - [x] Captcha:
+    - New members will face a simple captcha on groups with this enabled.
+    - All CAPTCHA messages are self-destructable, except the rejection ones.
+    - [x] `/enable_captcha`: Will enable the captcha in the group. Can only be executed by admins.
+    - [x] `/disable_captcha`: Will disable the captcha in the group. Can only be executed by admins.
  - [x] Self preservation habilities
     - [x] Handle deleted registered users and deregister those when identified
     - [x] Auto bans accounts with Cyrillic Characters _(huge sorry to all the eastern europeans for this, russians made me do it)_

fly.toml

@@ -4,6 +4,7 @@ app = "gringobot"
 kill_signal = "SIGINT"
 kill_timeout = 5
 processes = []
+primary_region = "ams"
 
 [env]
   NODE_ENV="production"

package.json

@@ -7,28 +7,31 @@
   "license": "MIT",
   "type": "module",
   "engines": {
-    "node": ">=19"
+    "node": ">=20"
   },
   "dependencies": {
     "async-retry": "^1.3.1",
     "await-to-js": "^3.0.0",
     "country-code-emoji": "^2.3.0",
-    "dotenv": "^8.2.0",
+    "dotenv": "^16.4.5",
     "got": "^12.5.3",
     "i18n-iso-countries": "^6.5.0",
     "js-yaml": "^4.1.0",
-    "lowdb": "^5.1.0",
+    "lowdb": "^7.0.0",
     "mkdirp": "^1.0.4",
     "mustache": "^4.2.0",
     "pino": "^8.10.0",
     "pino-pretty": "^9.3.0",
+    "sharp": "^0.33.2",
+    "svg-captcha": "^1.4.0",
     "telegraf": "^4.11.2",
     "telegram-format": "^2.1.0",
     "tslib": "^2.1.0",
     "yup": "^0.32.9"
   },
   "devDependencies": {
     "@types/async-retry": "^1.4.2",
+    "@types/dotenv": "^8.2.0",
     "@types/js-yaml": "^4.0.5",
     "@types/mkdirp": "^1.0.1",
     "@types/mustache": "^4.2.2",

src/autoDeleteMessages.ts

@@ -1,11 +1,7 @@
 import { to } from 'await-to-js';
 import retry, { RetryFunction } from 'async-retry';
 import { BotContext } from './context.js';
-
-const expired = (createdAt: number, timeout: number) => {
-  const minute = 60000;
-  return Math.floor((Date.now() - createdAt) / minute) >= timeout;
-};
+import { expired } from './utils/expired.js';
 
 export const runMessageRecycling = async (
   ctx: BotContext

src/autoKickCaptcha.ts

@@ -0,0 +1,104 @@
+import { to } from 'await-to-js';
+import retry, { RetryFunction } from 'async-retry';
+import { BotContext } from './context.js';
+import { expired } from './utils/expired.js';
+import { createMemberMention } from './member.js';
+
+// TODO: make timeout configurable
+const messageTimeout = 2;
+
+export const runCaptchaRecycling = async (
+  ctx: BotContext
+): Promise<void> => {
+  const database = await ctx.loadDatabase();
+
+  if (!database.isCaptchaEnabled) {
+    return;
+  }
+
+  const captcha = await database.getCaptcha();
+  const waitingUsers = captcha?.waitingUsers ?? {};
+
+  const promises = Object.entries(waitingUsers).map(
+    async ([userId, entry]) => {
+      const hasExpired = expired(entry.timestamp, messageTimeout);
+
+      ctx.logger.info(
+        `Captcha issued at ${entry.timestamp}: expiration status: '${
+          hasExpired ? 'expired' : 'not expired'
+        }'`
+      );
+
+      if (!hasExpired) {
+        /** the captcha still hasn't expired. */
+        return;
+      }
+
+      const id = Number(userId);
+      const chatId = ctx.chat?.id;
+
+      ctx.logger.info(
+        `Trying to kick user with id "${id}" from the chat "${chatId}", since captcha expired..`
+      );
+
+      const kickUser: RetryFunction<void> = async (bail, attempt) => {
+        const [kickUserError, kicked] = await to(
+          ctx.banChatMember(id, undefined, {
+            revoke_messages: true,
+          })
+        );
+
+        if (kicked) {
+          ctx.logger.info(
+            `Kicked user with id "${id}" from the chat "${chatId}"`
+          );
+          return;
+        }
+
+        if (kickUserError) {
+          ctx.logger.error(
+            `[Attempt No ${attempt}]: Failed to kick user with id "${id}" from the chat "${chatId}"`
+          );
+
+          const errorMessage =
+            // @ts-ignore
+            kickUserError.response.description;
+
+          ctx.logger.error(errorMessage);
+
+          throw kickUserError;
+        }
+      };
+
+      const [kickUserError] = await to(
+        retry(kickUser, {
+          retries: 3,
+        })
+      );
+
+      if (kickUserError) {
+        ctx.logger.error(
+          `Failed to kick user with id "${id}" from the chat:`
+        );
+        ctx.logger.error(kickUserError);
+      }
+
+      if (!kickUserError) {
+        ctx.logger.info(
+          `Kicked user with id "${id}" from the chat "${chatId}". Adding user to chat kicklist.`
+        );
+
+        const { t } = ctx.i18n;
+        await ctx.database.removeUserFromCaptchaWaitlist(entry.user);
+        await ctx.database.addUserToCaptchaKicklist(entry.user);
+        await ctx.replyWithMarkdown(
+          t('kick', 'userGotKickedCaptcha', {
+            kickedUser: createMemberMention(entry.user),
+          })
+        );
+      }
+    }
+  );
+
+  await Promise.all(promises);
+};

src/command.ts

@@ -18,6 +18,8 @@ export enum Command {
   FindRemoteMemberFrom = 'find_remote_member_from',
   Kick = 'kick',
   SetLanguage = 'set_language',
+  EnableCaptcha = 'enable_captcha',
+  DisableCaptcha = 'disable_captcha',
 }
 
 enum PortugueseCommandAlias {
@@ -36,6 +38,8 @@ enum PortugueseCommandAlias {
   RegisterRemoteMember = 'estou_remoto',
   FindRemoteMemberTo = 'quem_remoto_para',
   FindRemoteMemberFrom = 'quem_remoto_do',
+  EnableCaptcha = 'habilitar_captcha',
+  DisableCaptcha = 'desabilitar_captcha',
 }
 
 enum EnglishCommandAlias {
@@ -49,6 +53,8 @@ enum EnglishCommandAlias {
   DeregisterMemberFrom = 'leave',
   FindMember = 'whereami',
   SetLanguage = 'set_lang',
+  EnableCaptcha = 'captcha_on',
+  DisableCaptcha = 'captcha_off',
 }
 
 const DefaultCommandDescriptions: Record<Command, string> = {
@@ -79,6 +85,10 @@ const DefaultCommandDescriptions: Record<Command, string> = {
   [Command.Kick]: 'Ban mentioned user (Admin only)',
   [Command.SetLanguage]:
     'Sets the language that GringoBot should use in this (Admin only)',
+  [Command.EnableCaptcha]:
+    'Enable captcha for new members (Admin only)',
+  [Command.DisableCaptcha]:
+    'Disable captcha for new members (Admin only)',
 };
 
 const CommandDescriptionMap: Record<string, string> = {
@@ -101,6 +111,10 @@ const CommandDescriptionMap: Record<string, string> = {
     DefaultCommandDescriptions[Command.PingMembersAt],
   [EnglishCommandAlias.FindMember]:
     DefaultCommandDescriptions[Command.FindMember],
+  [EnglishCommandAlias.EnableCaptcha]:
+    DefaultCommandDescriptions[Command.EnableCaptcha],
+  [EnglishCommandAlias.DisableCaptcha]:
+    DefaultCommandDescriptions[Command.DisableCaptcha],
   [PortugueseCommandAlias.PingAdmins]: 'Notifica admins.',
   [PortugueseCommandAlias.RegisterMemberAt]:
     'Registra você em uma localização específica.',
@@ -128,6 +142,10 @@ const CommandDescriptionMap: Record<string, string> = {
     'Encontra pessoas que estão trabalhando remoto para um país',
   [PortugueseCommandAlias.RegisterRemoteMember]:
     'Se registra como trabalhando remoto',
+  [PortugueseCommandAlias.EnableCaptcha]:
+    'Habilita CAPTCHA para novos membros do grupo',
+  [PortugueseCommandAlias.DisableCaptcha]:
+    'Desabilita CAPTCHA para novos membros do grupo',
 };
 
 export const CommandDescriptions: BotCommand[] = Object.keys(
@@ -209,4 +227,12 @@ export const CommandAliases: Record<Command, string[]> = {
     Command.SetLanguage,
     EnglishCommandAlias.SetLanguage,
   ],
+  [Command.EnableCaptcha]: [
+    Command.EnableCaptcha,
+    PortugueseCommandAlias.EnableCaptcha,
+  ],
+  [Command.DisableCaptcha]: [
+    Command.DisableCaptcha,
+    PortugueseCommandAlias.DisableCaptcha,
+  ],
 };

src/commands/deregisterMemberFrom.ts

@@ -6,9 +6,9 @@ import {
   getCountryNameForCountryCode,
 } from '../countries.js';
 
-export const cmdDeregisterMemberFrom: MiddlewareFn<BotContext> = async (
-  ctx
-) => {
+export const cmdDeregisterMemberFrom: MiddlewareFn<
+  BotContext
+> = async (ctx) => {
   const i18n = ctx.i18n;
   const unsafeCountryName = markdown
     .escape(ctx.command.args ?? '')

src/commands/deregisterRemoteMember.ts

@@ -1,9 +1,9 @@
 import { MiddlewareFn } from 'telegraf';
 import { BotContext } from '../context.js';
 
-export const cmdDeregisterRemoteMember: MiddlewareFn<BotContext> = async (
-  ctx
-) => {
+export const cmdDeregisterRemoteMember: MiddlewareFn<
+  BotContext
+> = async (ctx) => {
   const i18n = ctx.i18n;
 
   await ctx.database.removeRemoteMember(ctx.safeUser.id);

src/commands/disableCaptcha.ts

@@ -0,0 +1,35 @@
+import { Middleware } from 'telegraf';
+import { BotContext } from '../context.js';
+import { to } from 'await-to-js';
+
+export const cmdDisableCaptcha: Middleware<BotContext> = async (
+  ctx
+) => {
+  const { t } = ctx.i18n;
+  const hasAdminAccess = await ctx.checkAdminAccess();
+
+  if (!hasAdminAccess) {
+    return ctx.replyWithAutoDestructiveMessage(
+      t('errors', 'mustBeAdminToUseCommand', {
+        mention: ctx.safeUser.mention,
+      })
+    );
+  }
+
+  const [err] = await to(ctx.database.disableCaptcha());
+
+  if (err) {
+    ctx.logger.error(`Failed to disable captcha.`, err);
+    return ctx.replyWithAutoDestructiveMessage(
+      t('errors', 'failedToDisableCaptcha', {
+        mention: ctx.safeUser.mention,
+      })
+    );
+  }
+
+  return ctx.replyWithAutoDestructiveMessage(
+    t('captcha', 'disabled', {
+      mention: ctx.safeUser.mention,
+    })
+  );
+};

src/commands/enableCaptcha.ts

@@ -0,0 +1,35 @@
+import { Middleware } from 'telegraf';
+import { BotContext } from '../context.js';
+
+export const cmdEnableCaptcha: Middleware<BotContext> = async (
+  ctx
+) => {
+  const { t } = ctx.i18n;
+  const hasAdminAccess = await ctx.checkAdminAccess();
+
+  if (!hasAdminAccess) {
+    return ctx.replyWithAutoDestructiveMessage(
+      t('errors', 'mustBeAdminToUseCommand', {
+        mention: ctx.safeUser.mention,
+      })
+    );
+  }
+
+  try {
+    await ctx.database.enableCaptcha();
+
+    return ctx.replyWithAutoDestructiveMessage(
+      t('captcha', 'enabled', {
+        mention: ctx.safeUser.mention,
+      })
+    );
+  } catch (err) {
+    ctx.logger.error(`Failed to enable captcha.`);
+    ctx.logger.error(err);
+    return ctx.replyWithAutoDestructiveMessage(
+      t('errors', 'failedToEnableCaptcha', {
+        mention: ctx.safeUser.mention,
+      })
+    );
+  }
+};

src/commands/listCountryMemberCount.ts

@@ -4,9 +4,9 @@ import { countryCodeEmoji } from 'country-code-emoji';
 import { BotContext } from '../context.js';
 import { getCountryNameForCountryCode } from '../countries.js';
 
-export const cmdListCountryMemberCount: MiddlewareFn<BotContext> = async (
-  ctx
-) => {
+export const cmdListCountryMemberCount: MiddlewareFn<
+  BotContext
+> = async (ctx) => {
   const i18n = ctx.i18n;
 
   const locationIndex = ctx.database.getLocationIndex();