feat: Add Telegram bot with group support

- Full Telegram bot implementation for Lightning Jackpot
- Commands: /start, /buy, /tickets, /wins, /address, /jackpot, /help
- Lightning invoice generation with QR codes
- Payment polling and confirmation notifications
- User state management (Redis/in-memory fallback)
- Group support with admin settings panel
- Configurable draw announcements and reminders
- Centralized messages for easy i18n
- Docker configuration included

telegram_bot/src/services/api.ts

@@ -0,0 +1,145 @@
+import axios, { AxiosInstance, AxiosError } from 'axios';
+import config from '../config';
+import { logger, logApiCall } from './logger';
+import {
+  ApiResponse,
+  JackpotNextResponse,
+  BuyTicketsResponse,
+  TicketStatusResponse,
+} from '../types';
+
+class ApiClient {
+  private client: AxiosInstance;
+
+  constructor() {
+    this.client = axios.create({
+      baseURL: config.api.baseUrl,
+      timeout: 30000,
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+
+    // Response interceptor for logging
+    this.client.interceptors.response.use(
+      (response) => {
+        logApiCall(
+          response.config.url || '',
+          response.config.method?.toUpperCase() || 'GET',
+          response.status
+        );
+        return response;
+      },
+      (error: AxiosError) => {
+        logApiCall(
+          error.config?.url || '',
+          error.config?.method?.toUpperCase() || 'GET',
+          error.response?.status,
+          error.message
+        );
+        throw error;
+      }
+    );
+  }
+
+  /**
+   * Get next jackpot cycle information
+   */
+  async getNextJackpot(): Promise<JackpotNextResponse | null> {
+    try {
+      const response = await this.client.get<ApiResponse<JackpotNextResponse>>(
+        '/jackpot/next'
+      );
+      return response.data.data;
+    } catch (error) {
+      if (axios.isAxiosError(error)) {
+        const status = error.response?.status;
+        if (status === 503) {
+          // No active lottery or cycle
+          return null;
+        }
+      }
+      logger.error('Failed to get next jackpot', { error });
+      throw error;
+    }
+  }
+
+  /**
+   * Buy lottery tickets
+   */
+  async buyTickets(
+    tickets: number,
+    lightningAddress: string,
+    telegramUserId: number
+  ): Promise<BuyTicketsResponse> {
+    try {
+      const response = await this.client.post<ApiResponse<BuyTicketsResponse>>(
+        '/jackpot/buy',
+        {
+          tickets,
+          lightning_address: lightningAddress,
+          buyer_name: `TG:${telegramUserId}`,
+        }
+      );
+      return response.data.data;
+    } catch (error) {
+      if (axios.isAxiosError(error)) {
+        const errorData = error.response?.data as ApiResponse<unknown>;
+        if (errorData?.error) {
+          throw new Error(errorData.message || errorData.error);
+        }
+      }
+      logger.error('Failed to buy tickets', { error });
+      throw error;
+    }
+  }
+
+  /**
+   * Get ticket purchase status
+   */
+  async getTicketStatus(purchaseId: string): Promise<TicketStatusResponse | null> {
+    try {
+      const response = await this.client.get<ApiResponse<TicketStatusResponse>>(
+        `/tickets/${purchaseId}`
+      );
+      return response.data.data;
+    } catch (error) {
+      if (axios.isAxiosError(error) && error.response?.status === 404) {
+        return null;
+      }
+      logger.error('Failed to get ticket status', { error, purchaseId });
+      throw error;
+    }
+  }
+
+  /**
+   * Get user's ticket purchases by lightning address
+   * Note: This queries tickets by lightning address pattern matching
+   */
+  async getUserTickets(
+    telegramUserId: number,
+    limit: number = 10,
+    offset: number = 0
+  ): Promise<TicketStatusResponse[]> {
+    // Since the backend doesn't have Telegram-specific endpoints,
+    // we'll need to track purchases locally in state
+    // This is a placeholder for future backend integration
+    return [];
+  }
+
+  /**
+   * Health check
+   */
+  async healthCheck(): Promise<boolean> {
+    try {
+      await this.client.get('/jackpot/next');
+      return true;
+    } catch (error) {
+      return false;
+    }
+  }
+}
+
+export const apiClient = new ApiClient();
+export default apiClient;
+