Fix reminder scheduling and add group features

- Fix reminder duplicate bug: use slot-only keys to prevent multiple reminders when settings change - Add New Jackpot announcement delay setting for groups (default 5 min) - Cancel unpaid purchases after draw completes (prevents payments for past rounds) - Add BotFather commands template file - Update README documentation
2025-12-08 23:49:54 +00:00
parent 13fd2b8989
commit 86e2e0a321
10 changed files with 366 additions and 51 deletions
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# ⚡ Lightning Lottery
+# ⚡ Lightning Lotto

 A complete Bitcoin Lightning Network powered lottery system with instant payouts to Lightning Addresses.

@@ -10,24 +10,27 @@ A complete Bitcoin Lightning Network powered lottery system with instant payouts
 - 🌐 **Anonymous or Nostr**: Buy tickets anonymously or login with Nostr
 - 📱 **Mobile First**: Beautiful responsive design optimized for all devices
 - 🏆 **Automatic Payouts**: Winners get paid automatically to their Lightning Address
- ⏰ **Multiple Cycles**: Support for hourly, daily, weekly, and monthly draws
+- ⏰ **Flexible Cycles**: Configurable draw intervals (minutes, hours, days, weekly, or cron)
 - 🔄 **Auto-Redraw**: If payout fails, automatically selects a new winner
 - 🎰 **Random Tickets**: Ticket numbers are randomly generated, not sequential
 - 📊 **Swagger Docs**: Full API documentation at `/api-docs`
+- 🤖 **Telegram Bot**: Full-featured bot for buying tickets and receiving notifications

 ## Architecture

-The system consists of three main components:
+The system consists of four main components:

 1. **Backend API** (Node.js + TypeScript + Express)
 2. **Frontend** (Next.js + React + TypeScript + TailwindCSS)
-3. **Database** (PostgreSQL or SQLite)
+3. **Telegram Bot** (Node.js + TypeScript + node-telegram-bot-api)
+4. **Database** (PostgreSQL or SQLite)

 ### Backend

 - RESTful API with comprehensive endpoints
 - LNbits integration for Lightning payments
 - Automated scheduler for draws and cycle generation
+- Configurable cycle types (minutes, hours, days, weekly, cron)
 - JWT authentication for Nostr users
 - Admin API for manual operations
 - Payment monitoring with polling fallback
@@ -36,13 +39,23 @@ The system consists of three main components:
 ### Frontend

 - Server-side rendered Next.js application
- Redux state management
 - Real-time countdown timers
 - Invoice QR code display with payment animations
 - Automatic status polling
 - Nostr NIP-07 authentication
 - Draw animation with winner reveal
 - Past winners display
+- Fully responsive mobile-first design
+
+### Telegram Bot
+
+- Buy tickets directly from Telegram
+- Lightning Address management (with 21Tipbot & Bittip integration)
+- View tickets and wins
+- Notification preferences (draw reminders, results, new jackpot alerts)
+- Group support with admin controls
+- Customizable reminders (up to 3 reminder slots per group)
+- SQLite database for persistent user/group settings

 ## Quick Start

@@ -58,7 +71,8 @@ cd LightningLotto
 ```bash
 cp back_end/env.example back_end/.env
 cp front_end/env.example front_end/.env.local
-# Edit both files with your configuration
+cp telegram_bot/env.example telegram_bot/.env
+# Edit all files with your configuration
 ```

 3. Start services:
@@ -113,6 +127,22 @@ npm run build
 npm start
 ```

+#### Telegram Bot
+
+```bash
+cd telegram_bot
+npm install
+cp env.example .env
+# Edit .env with your bot token and API URL
+
+# Run development server
+npm run dev
+
+# Or build and run production
+npm run build
+npm start
+```
+
 ## Configuration

 ### Required Environment Variables
@@ -138,6 +168,15 @@ ADMIN_API_KEY=your-admin-api-key
 DEFAULT_TICKET_PRICE_SATS=1000
 DEFAULT_HOUSE_FEE_PERCENT=5
 PAYOUT_MAX_ATTEMPTS_BEFORE_REDRAW=2
+
+# Cycle Configuration (choose one type)
+CYCLE_TYPE=hours                    # minutes | hours | days | weekly | cron
+CYCLE_INTERVAL_MINUTES=30           # For 'minutes' type
+CYCLE_INTERVAL_HOURS=1              # For 'hours' type
+CYCLE_DAILY_TIME=20:00              # For 'days' type (HH:MM UTC)
+CYCLE_WEEKLY_DAY=saturday           # For 'weekly' type
+CYCLE_WEEKLY_TIME=20:00             # For 'weekly' type (HH:MM UTC)
+CYCLE_CRON_EXPRESSION=0 */6 * * *   # For 'cron' type
 ```

 #### Frontend (.env.local)
@@ -146,7 +185,16 @@ PAYOUT_MAX_ATTEMPTS_BEFORE_REDRAW=2
 NEXT_PUBLIC_API_BASE_URL=http://localhost:3000
 ```

-See `back_end/env.example` and `front_end/env.example` for all configuration options.
+#### Telegram Bot (.env)
+
+```bash
+TELEGRAM_BOT_TOKEN=your-telegram-bot-token
+API_BASE_URL=http://localhost:3000
+FRONTEND_BASE_URL=http://localhost:3001
+# BOT_DATABASE_PATH=./data/bot.db  # Optional, defaults to ./data/bot.db
+```
+
+See `back_end/env.example`, `front_end/env.example`, and `telegram_bot/env.example` for all configuration options.

 ## API Endpoints

@@ -186,9 +234,39 @@ See `back_end/env.example` and `front_end/env.example` for all configuration opt

 Full API documentation available at `/api-docs` (Swagger UI).

+## Telegram Bot Commands
+
+### Private Chat Commands
+
+| Command | Description |
+|---------|-------------|
+| `/start` | Start the bot and register |
+| `/lottomenu` | Show main menu |
+| `/buyticket` | Buy lottery tickets |
+| `/tickets` | View your tickets |
+| `/wins` | View your wins |
+| `/lottoaddress` | Set your Lightning Address |
+| `/lottosettings` | Notification settings |
+| `/lottohelp` | Show help |
+
+### Group Commands (Admin Only)
+
+| Command | Description |
+|---------|-------------|
+| `/lottosettings` | Configure group lottery settings |
+| `/jackpot` | Show current jackpot info |
+
+### Group Features
+
+- Enable/disable draw announcements
+- Enable/disable new jackpot alerts
+- Up to 3 customizable draw reminders
+- Adjustable reminder times (minutes/hours/days)
+- Auto-deleting settings messages (2 min TTL)
+
 ## Database Schema

-7 main tables:
+### Backend Database (7 main tables)

 - `lotteries` - Lottery configuration
 - `jackpot_cycles` - Draw cycles with status and winners
@@ -198,15 +276,23 @@ Full API documentation available at `/api-docs` (Swagger UI).
 - `users` - Nostr user accounts (optional)
 - `draw_logs` - Audit trail for transparency

+### Telegram Bot Database (SQLite)
+
+- `users` - Telegram user profiles and notification preferences
+- `user_purchases` - Tracks purchases per user
+- `cycle_participants` - Tracks participants per cycle
+- `groups` - Group settings and reminder configurations
+
 ## How It Works

 1. **Cycle Generation**: Scheduler automatically creates future draw cycles
-2. **Ticket Purchase**: Users buy tickets, receive Lightning invoice
+2. **Ticket Purchase**: Users buy tickets via web or Telegram, receive Lightning invoice
 3. **Payment Processing**: LNbits webhook or polling confirms payment
 4. **Ticket Issuance**: Random ticket numbers assigned in database transaction
 5. **Draw Execution**: At scheduled time, winner selected using CSPRNG
-6. **Payout**: Winner's Lightning Address paid automatically
-7. **Retry/Redraw**: Failed payouts retried; new winner drawn after max attempts
+6. **Notifications**: Telegram bot sends draw results to participants and groups
+7. **Payout**: Winner's Lightning Address paid automatically
+8. **Retry/Redraw**: Failed payouts retried; new winner drawn after max attempts

 ## Security Features

@@ -219,6 +305,7 @@ Full API documentation available at `/api-docs` (Swagger UI).
 - `crypto.randomBytes()` for winner selection
 - `crypto.randomInt()` for ticket number generation
 - No floating-point math (BIGINT for all sats)
+- Lightning Address LNURL verification

 ## Frontend Pages

@@ -233,21 +320,18 @@ Full API documentation available at `/api-docs` (Swagger UI).
 | `/dashboard/tickets` | User's ticket history |
 | `/dashboard/wins` | User's win history |

-## Testing
+## Production Deployment

-### Backend Tests
-```bash
-cd back_end
-npm test
-```
+### Systemd Services & Nginx

-### Frontend Tests
-```bash
-cd front_end
-npm test
-```
+The `setup/` folder contains production-ready configuration files:

-## Deployment
+- `lightning-lotto-backend.service` - Backend systemd service
+- `lightning-lotto-frontend.service` - Frontend systemd service
+- `lightning-lotto-telegram.service` - Telegram bot systemd service
+- `nginx-lightning-lotto.conf` - Nginx reverse proxy with SSL
+
+See `setup/README.md` for detailed deployment instructions.

 ### Production Considerations

@@ -298,11 +382,38 @@ LightningLotto/
 │       ├── components/     # React components
 │       ├── config/         # Frontend config
 │       ├── constants/      # Text strings
-│       ├── lib/            # API client and utilities
-│       └── store/          # Redux state
+│       └── lib/            # API client and utilities
+├── telegram_bot/
+│   ├── src/
+│   │   ├── config/         # Bot configuration
+│   │   ├── handlers/       # Command and callback handlers
+│   │   ├── messages/       # Centralized message strings
+│   │   ├── services/       # Database, API, notifications
+│   │   ├── types/          # TypeScript types
+│   │   └── utils/          # Keyboards, formatting
+│   └── data/               # SQLite database for bot
+├── setup/                  # Production deployment configs
+│   ├── *.service           # Systemd service files
+│   ├── nginx-*.conf        # Nginx configuration
+│   └── README.md           # Deployment guide
+├── App_info/               # Documentation
 └── docker-compose.yml
 ```

+## Testing
+
+### Backend Tests
+```bash
+cd back_end
+npm test
+```
+
+### Frontend Tests
+```bash
+cd front_end
+npm test
+```
+
 ## License

 MIT License - see LICENSE file for details
@@ -311,6 +422,7 @@ MIT License - see LICENSE file for details

 - Built with [LNbits](https://lnbits.com/) for Lightning Network integration
 - Uses [Nostr](https://nostr.com/) for decentralized authentication
+- Telegram bot integration for mobile-first experience
 - Inspired by the Bitcoin Lightning Network community

 ---
--- a/back_end/src/scheduler/index.ts
+++ b/back_end/src/scheduler/index.ts
@@ -242,6 +242,8 @@ async function checkAndExecuteDraws(): Promise<void> {
    for (const cycle of result.rows) {
      console.log(`Executing draw for cycle ${cycle.id} (${cycle.cycle_type})`);
      await executeDraw(cycle.id);
+      // Cancel unpaid invoices for this cycle after draw
+      await cancelUnpaidPurchases(cycle.id);
    }

  } catch (error) {
@@ -249,6 +251,30 @@ async function checkAndExecuteDraws(): Promise<void> {
  }
 }

+/**
+ * Cancel unpaid purchases after a draw completes
+ * This prevents payments for invoices from past rounds
+ */
+async function cancelUnpaidPurchases(cycleId: string): Promise<void> {
+  try {
+    const result = await db.query(
+      `UPDATE ticket_purchases 
+       SET status = 'cancelled', updated_at = NOW()
+       WHERE cycle_id = $1 
+       AND status = 'pending'
+       RETURNING id`,
+      [cycleId]
+    );
+
+    const cancelledCount = result.rows.length;
+    if (cancelledCount > 0) {
+      console.log(`Cancelled ${cancelledCount} unpaid purchases for cycle ${cycleId}`);
+    }
+  } catch (error) {
+    console.error('Error cancelling unpaid purchases:', error);
+  }
+}
+
 /**
 * Update cycles to 'sales_open' status when appropriate
 */
--- a/telegram_bot/botfather_commands.txt
+++ b/telegram_bot/botfather_commands.txt
@@ -0,0 +1,71 @@
+================================
+BOTFATHER COMMAND SETUP
+================================
+
+Send to @BotFather: /setcommands
+Then select your bot and paste the commands below:
+
+================================
+PRIVATE CHAT COMMANDS
+================================
+
+start - Start the bot and register
+lottomenu - Show main menu
+buyticket - Buy lottery tickets
+tickets - View your tickets
+wins - View your wins
+lottoaddress - Set your Lightning Address
+lottosettings - Notification settings
+lottohelp - Show help
+jackpot - Show current jackpot
+
+================================
+GROUP COMMANDS (Optional)
+================================
+
+If you want separate commands for groups, use /setcommands again
+and select "Edit commands for groups":
+
+jackpot - Show current jackpot info
+lottosettings - Configure lottery settings (admin only)
+lottohelp - Show help and commands
+
+================================
+BOT DESCRIPTION
+================================
+
+Send to @BotFather: /setdescription
+
+Lightning Lotto - Win Bitcoin on the Lightning Network! ⚡
+
+Buy lottery tickets with Lightning, get instant payouts if you win.
+• Buy tickets with sats
+• Set your Lightning Address for payouts
+• Get notified about draws and wins
+• Join groups to get jackpot alerts
+
+================================
+ABOUT TEXT
+================================
+
+Send to @BotFather: /setabouttext
+
+⚡ Lightning Lotto Bot ⚡
+
+A provably fair Bitcoin lottery powered by the Lightning Network.
+
+🎟️ Buy tickets with Lightning
+💰 Instant payouts to your Lightning Address
+🔔 Draw reminders & win notifications
+👥 Group support with announcements
+
+Start with /start to begin!
+
+================================
+SHORT DESCRIPTION
+================================
+
+Send to @BotFather: /setshortdescription
+
+Win Bitcoin on the Lightning Network! Buy lottery tickets, get instant payouts. ⚡
+
--- a/telegram_bot/src/handlers/groups.ts
+++ b/telegram_bot/src/handlers/groups.ts
@@ -6,6 +6,7 @@ import {
  GroupSettings, 
  REMINDER_PRESETS, 
  ANNOUNCEMENT_DELAY_OPTIONS,
+  NEW_JACKPOT_DELAY_OPTIONS,
  DEFAULT_GROUP_REMINDER_SLOTS,
  ReminderTime,
  formatReminderTime,
@@ -268,6 +269,20 @@ export async function handleGroupSettingsCallback(
      }
    }

+    // Handle new jackpot delay selection
+    if (action.startsWith('newjackpot_delay_')) {
+      const minutes = parseInt(action.replace('newjackpot_delay_', ''), 10);
+      if (!isNaN(minutes)) {
+        updatedSettings = await groupStateManager.updateNewJackpotDelay(chatId, minutes);
+        if (updatedSettings) {
+          logUserAction(userId, 'Updated new jackpot delay', { groupId: chatId, minutes });
+          await bot.answerCallbackQuery(query.id, { 
+            text: minutes === 0 ? 'Announce immediately' : `Announce ${minutes} min after new jackpot` 
+          });
+        }
+      }
+    }
+
    // Handle reminder time adjustments (reminder1_add_1_hours, reminder2_sub_1_days, etc.)
    const reminderTimeMatch = action.match(/^reminder(\d)_(add|sub)_(\d+)_(minutes|hours|days)$/);
    if (reminderTimeMatch) {
@@ -334,7 +349,7 @@ export async function handleGroupSettingsCallback(


 /**
- * Format delay option for display
+ * Format delay option for display (seconds)
 */
 function formatDelayOption(seconds: number): string {
  if (seconds === 0) return 'Instant';
@@ -345,6 +360,14 @@ function formatDelayOption(seconds: number): string {
  return `${seconds}s`;
 }

+/**
+ * Format new jackpot delay option for display (minutes)
+ */
+function formatNewJackpotDelay(minutes: number): string {
+  if (minutes === 0) return 'Instant';
+  return minutes === 1 ? '1 min' : `${minutes} min`;
+}
+
 /**
 * Get time adjustment buttons for a reminder slot
 */
@@ -385,12 +408,23 @@ function getGroupSettingsKeyboard(settings: GroupSettings): TelegramBot.InlineKe
      text: `${onOff(settings.newJackpotAnnouncement)} New Jackpot Announcement`,
      callback_data: 'group_toggle_newjackpot',
    }],
-    [{
-      text: `${onOff(settings.drawAnnouncements)} Draw Result Announcements`,
-      callback_data: 'group_toggle_announcements',
-    }],
  ];

+  // Add new jackpot delay options if enabled
+  if (settings.newJackpotAnnouncement !== false) {
+    keyboard.push(
+      NEW_JACKPOT_DELAY_OPTIONS.map(minutes => ({
+        text: `${selected(settings.newJackpotDelayMinutes ?? 5, minutes)} ${formatNewJackpotDelay(minutes)}`,
+        callback_data: `group_newjackpot_delay_${minutes}`,
+      }))
+    );
+  }
+
+  keyboard.push([{
+    text: `${onOff(settings.drawAnnouncements)} Draw Result Announcements`,
+    callback_data: 'group_toggle_announcements',
+  }]);
+
  // Add announcement delay options if announcements are enabled
  if (settings.drawAnnouncements) {
    keyboard.push(
--- a/telegram_bot/src/index.ts
+++ b/telegram_bot/src/index.ts
@@ -354,6 +354,13 @@ bot.on('callback_query', async (query) => {
      return;
    }

+    // Handle new jackpot announcement delay selection
+    if (data.startsWith('group_newjackpot_delay_')) {
+      const action = data.replace('group_', '');
+      await handleGroupSettingsCallback(bot, query, action);
+      return;
+    }
+
    // Handle group refresh
    if (data === 'group_refresh') {
      await handleGroupRefresh(bot, query);
--- a/telegram_bot/src/messages/index.ts
+++ b/telegram_bot/src/messages/index.ts
@@ -603,6 +603,7 @@ To buy tickets privately, message me directly! 🎟`,
      reminder3Enabled?: boolean;
      reminder3Time?: { value: number; unit: string };
      announcementDelaySeconds?: number;
+      newJackpotDelayMinutes?: number;
    }) => {
      const announceDelay = settings.announcementDelaySeconds ?? 10;
      const formatAnnounce = announceDelay === 0 
@@ -611,6 +612,11 @@ To buy tickets privately, message me directly! 🎟`,
          ? `${announceDelay / 60} min after draw`
          : `${announceDelay}s after draw`;

+      const newJackpotDelay = settings.newJackpotDelayMinutes ?? 5;
+      const formatNewJackpotDelay = newJackpotDelay === 0 
+        ? 'Immediately'
+        : `${newJackpotDelay} min after start`;
+      
      // Format helper for reminder times
      const formatTime = (t?: { value: number; unit: string }) => {
        if (!t) return '?';
@@ -639,7 +645,7 @@ To buy tickets privately, message me directly! 🎟`,

 *Current Configuration:*
 ${settings.enabled ? '✅' : '❌'} Bot Enabled
-${newJackpot ? '✅' : '❌'} New Jackpot Announcements
+${newJackpot ? '✅' : '❌'} New Jackpot Announcements ${newJackpot ? `_(${formatNewJackpotDelay})_` : ''}
 ${settings.drawAnnouncements ? '✅' : '❌'} Draw Announcements ${settings.drawAnnouncements ? `_(${formatAnnounce})_` : ''}
 ${settings.reminders ? '✅' : '❌'} Draw Reminders ${settings.reminders ? `_(${formatReminderList})_` : ''}
 ${settings.ticketPurchaseAllowed ? '✅' : '❌'} Ticket Purchases in Group
--- a/telegram_bot/src/services/database.ts
+++ b/telegram_bot/src/services/database.ts
@@ -105,6 +105,7 @@ class BotDatabase {
        reminder3_enabled INTEGER DEFAULT 0,
        reminder3_time TEXT DEFAULT '{"value":6,"unit":"days"}',
        announcement_delay_seconds INTEGER DEFAULT 10,
+        new_jackpot_delay_minutes INTEGER DEFAULT 5,
        added_by INTEGER,
        added_at TEXT DEFAULT CURRENT_TIMESTAMP,
        updated_at TEXT DEFAULT CURRENT_TIMESTAMP
@@ -515,6 +516,7 @@ class BotDatabase {
        reminder3_enabled = ?,
        reminder3_time = ?,
        announcement_delay_seconds = ?,
+        new_jackpot_delay_minutes = ?,
        updated_at = CURRENT_TIMESTAMP
      WHERE group_id = ?
    `).run(
@@ -531,6 +533,7 @@ class BotDatabase {
      settings.reminder3Enabled ? 1 : 0,
      JSON.stringify(settings.reminder3Time),
      settings.announcementDelaySeconds,
+      settings.newJackpotDelayMinutes ?? 5,
      settings.groupId
    );
  }
@@ -580,6 +583,18 @@ class BotDatabase {
    return this.getGroup(groupId);
  }

+  /**
+   * Update new jackpot announcement delay
+   */
+  updateNewJackpotDelay(groupId: number, minutes: number): GroupSettings | null {
+    const group = this.getGroup(groupId);
+    if (!group) return null;
+
+    group.newJackpotDelayMinutes = minutes;
+    this.saveGroup(group);
+    return this.getGroup(groupId);
+  }
+
  /**
   * Get groups with a specific feature enabled
   */
@@ -627,6 +642,7 @@ class BotDatabase {
      reminder3Time: row.reminder3_time ? JSON.parse(row.reminder3_time) : { value: 6, unit: 'days' },
      reminderTimes: [], // Legacy field
      announcementDelaySeconds: row.announcement_delay_seconds || 10,
+      newJackpotDelayMinutes: row.new_jackpot_delay_minutes ?? 5,
      addedBy: row.added_by,
      addedAt: new Date(row.added_at),
      updatedAt: new Date(row.updated_at),
--- a/telegram_bot/src/services/groupState.ts
+++ b/telegram_bot/src/services/groupState.ts
@@ -81,6 +81,16 @@ class GroupStateManager {
    return botDatabase.updateAnnouncementDelay(groupId, seconds);
  }

+  /**
+   * Update new jackpot announcement delay
+   */
+  async updateNewJackpotDelay(
+    groupId: number,
+    minutes: number
+  ): Promise<GroupSettings | null> {
+    return botDatabase.updateNewJackpotDelay(groupId, minutes);
+  }
+
  /**
   * Get groups with specific feature enabled
   */
--- a/telegram_bot/src/services/notificationScheduler.ts
+++ b/telegram_bot/src/services/notificationScheduler.ts
@@ -270,26 +270,34 @@ class NotificationScheduler {
    this.announcedCycles.add(`new:${cycle.id}`);

    const drawTime = new Date(cycle.scheduled_at);
+    const bot = this.bot;
    
-    // Send to groups
+    // Send to groups (with configurable delay)
    const groups = await groupStateManager.getGroupsWithFeature('enabled');
    for (const group of groups) {
      if (group.newJackpotAnnouncement === false) continue;

-      try {
-        const message = messages.notifications.newJackpot(
-          lottery.name,
-          lottery.ticket_price_sats,
-          drawTime
-        );
-        await this.bot.sendMessage(group.groupId, message, { parse_mode: 'Markdown' });
-        logger.debug('Sent new jackpot announcement to group', { groupId: group.groupId });
-      } catch (error) {
-        this.handleSendError(error, group.groupId);
-      }
+      const delayMs = (group.newJackpotDelayMinutes ?? 5) * 60 * 1000;
+      
+      setTimeout(async () => {
+        try {
+          const message = messages.notifications.newJackpot(
+            lottery.name,
+            lottery.ticket_price_sats,
+            drawTime
+          );
+          await bot.sendMessage(group.groupId, message, { parse_mode: 'Markdown' });
+          logger.debug('Sent new jackpot announcement to group', { 
+            groupId: group.groupId,
+            delayMinutes: group.newJackpotDelayMinutes ?? 5
+          });
+        } catch (error) {
+          this.handleSendError(error, group.groupId);
+        }
+      }, delayMs);
    }

-    // Send to users with new jackpot alerts enabled
+    // Send to users with new jackpot alerts enabled (immediate)
    const users = await stateManager.getUsersWithNotification('newJackpotAlerts');
    for (const user of users) {
      try {
@@ -305,7 +313,7 @@ class NotificationScheduler {
      }
    }

-    logger.info('New jackpot announcements sent', { cycleId: cycle.id });
+    logger.info('New jackpot announcements scheduled/sent', { cycleId: cycle.id });
  }

  /**
@@ -477,11 +485,29 @@ class NotificationScheduler {
      }

      for (const { slot, time: reminderTime } of enabledReminders) {
-        const reminderKey = `slot${slot}_${formatReminderTime(reminderTime)}`;
-        const uniqueKey = `group:${group.groupId}:${cycle.id}:${reminderKey}`;
+        // Use slot-only key to prevent duplicate reminders when settings change
+        const uniqueKey = `group:${group.groupId}:${cycle.id}:slot${slot}`;

-        if (this.scheduledReminders.has(uniqueKey)) {
-          continue;
+        // Check if we already have a reminder for this slot
+        const existingReminder = this.scheduledReminders.get(uniqueKey);
+        if (existingReminder) {
+          // If settings changed (different time), cancel old and reschedule
+          const newMinutesBefore = reminderTimeToMinutes(reminderTime);
+          const newReminderDate = new Date(drawTime.getTime() - newMinutesBefore * 60 * 1000);
+          
+          // Only reschedule if the time actually changed
+          if (existingReminder.scheduledFor.getTime() !== newReminderDate.getTime()) {
+            clearTimeout(existingReminder.timeout);
+            this.scheduledReminders.delete(uniqueKey);
+            logger.debug('Cleared old reminder due to settings change', {
+              groupId: group.groupId,
+              slot,
+              oldTime: existingReminder.scheduledFor.toISOString(),
+              newTime: newReminderDate.toISOString(),
+            });
+          } else {
+            continue; // Same time, skip
+          }
        }

        const minutesBefore = reminderTimeToMinutes(reminderTime);
@@ -501,7 +527,7 @@ class NotificationScheduler {
        this.scheduledReminders.set(uniqueKey, {
          groupId: group.groupId,
          cycleId: cycle.id,
-          reminderKey,
+          reminderKey: `slot${slot}_${formatReminderTime(reminderTime)}`,
          scheduledFor: reminderDate,
          timeout,
        });
@@ -510,7 +536,7 @@ class NotificationScheduler {
          groupId: group.groupId,
          cycleId: cycle.id,
          slot,
-          reminderKey,
+          time: formatReminderTime(reminderTime),
          scheduledFor: reminderDate.toISOString(),
        });
      }
--- a/telegram_bot/src/types/groups.ts
+++ b/telegram_bot/src/types/groups.ts
@@ -27,6 +27,7 @@ export interface GroupSettings {
  // Legacy field (kept for backwards compat, no longer used)
  reminderTimes: ReminderTime[];
  announcementDelaySeconds: number; // Delay after draw to send announcement (in seconds)
+  newJackpotDelayMinutes: number; // Delay after new jackpot starts to send announcement (in minutes)
  addedBy: number;
  addedAt: Date;
  updatedAt: Date;
@@ -84,6 +85,11 @@ export function formatReminderTime(rt: ReminderTime): string {
 */
 export const ANNOUNCEMENT_DELAY_OPTIONS = [0, 10, 30, 60, 120];

+/**
+ * Available new jackpot announcement delay options (minutes after start)
+ */
+export const NEW_JACKPOT_DELAY_OPTIONS = [0, 1, 5, 10, 15, 30];
+
 /**
 * Default group settings
 */
@@ -101,6 +107,7 @@ export const DEFAULT_GROUP_SETTINGS: Omit<GroupSettings, 'groupId' | 'groupTitle
  reminder3Time: { value: 6, unit: 'days' },    // Default: 6 days before
  reminderTimes: [], // Legacy field
  announcementDelaySeconds: 10, // Default: 10 seconds after draw
+  newJackpotDelayMinutes: 5, // Default: 5 minutes after new jackpot starts
 };