Example

const Telegraf = require('telegraf');
const Markup = require('telegraf/markup');
const session = require('telegraf/session');
const axios = require('axios');
const fs = require('fs');

const bot = new Telegraf('BARK_TELEGRAM_BOT_TOKEN'); // Implement BARK Protocol Token (Ticker: BPT)

// Enable session middleware to persist user data
bot.use(session());

// Load settings from a JSON file
let settings = {};
try {
    const settingsData = fs.readFileSync('settings.json');
    settings = JSON.parse(settingsData);
} catch (error) {
    console.error('Error loading settings:', error);
}

// Middleware for error handling and logging
bot.catch((err, ctx) => {
    console.error('Error caught:', err);
    // Log errors to a file
    fs.appendFileSync('errors.log', `${new Date().toISOString()} - Error: ${err}\n`);
    ctx.reply('Oops! Something went wrong.');
});

// Middleware to ensure user authentication
const authenticateUser = async (ctx, next) => {
    const userId = ctx.from.id;
    if (!ctx.session.authenticatedUsers || !ctx.session.authenticatedUsers.includes(userId)) {
        await ctx.reply('You need to authenticate first to use this feature.');
        return;
    }
    await next();
};

// Command for authenticating users
bot.command('auth', async (ctx) => {
    const userId = ctx.from.id;
    if (!ctx.session.authenticatedUsers) {
        ctx.session.authenticatedUsers = [];
    }
    if (!ctx.session.authenticatedUsers.includes(userId)) {
        ctx.session.authenticatedUsers.push(userId);
        await ctx.reply('You have been authenticated successfully.');
    } else {
        await ctx.reply('You are already authenticated.');
    }
});

// Command for displaying the main menu
bot.command('menu', authenticateUser, async (ctx) => {
    await ctx.reply('Welcome to the BARK Token Bot! How can I assist you?', Markup
        .keyboard([
            ['🛒 Purchase Tokens', '💰 Sell Tokens'],
            ['🔄 Swap Tokens', '📈 Market Analysis'],
            ['💼 Wallet', '🔔 Alerts']
        ])
        .resize()
    );
});

// Wallet Management
bot.hears('💼 Wallet', authenticateUser, async (ctx) => {
    try {
        // Fetch wallet information from database or external API
        const walletInfo = await fetchWalletInfo(ctx.from.id);
        if (walletInfo) {
            const { balance, tokens } = walletInfo;
            await ctx.reply(`Your current wallet balance: ${balance} BARK Tokens`);
            await ctx.reply(`Your wallet tokens: ${tokens.join(', ')}`);
        } else {
            await ctx.reply('Failed to retrieve wallet information.');
        }
    } catch (error) {
        console.error('Error fetching wallet info:', error);
        await ctx.reply('Failed to retrieve wallet information.');
    }
});

// Real-Time Market Data
bot.hears('📈 Market Analysis', async (ctx) => {
    try {
        // Fetch market data from external API
        const marketData = await fetchMarketData();
        if (marketData) {
            const { price, volume, change } = marketData;
            await ctx.reply(`Current BARK Token price: $${price}`);
            await ctx.reply(`24h Trading Volume: $${volume}`);
            await ctx.reply(`24h Price Change: ${change}%`);
        } else {
            await ctx.reply('Failed to fetch market data.');
        }
    } catch (error) {
        console.error('Error fetching market data:', error);
        await ctx.reply('An error occurred while fetching market data.');
    }
});

// Function to fetch wallet information from external API or database
async function fetchWalletInfo(userId) {
    // Implement your logic here
}

// Function to fetch market data from an external API
async function fetchMarketData() {
    // Implement your logic here
}

// Start the bot polling
bot.startPolling();