bunq/example.pagination.ts

import { BunqAccount, IBunqPaginationOptions } from './ts/index.js';

// Example demonstrating the enhanced pagination support in getTransactions

async function demonstratePagination() {
  const bunq = new BunqAccount({
    apiKey: 'your-api-key',
    deviceName: 'Pagination Demo',
    environment: 'PRODUCTION',
  });

  // Initialize and get session
  const sessionData = await bunq.init();
  
  // Get accounts
  const { accounts } = await bunq.getAccounts();
  const account = accounts[0];

  // Example 1: Get most recent transactions (default behavior)
  const recentTransactions = await account.getTransactions();
  console.log(`Got ${recentTransactions.length} recent transactions`);

  // Example 2: Get transactions with custom count
  const smallBatch = await account.getTransactions({ count: 10 });
  console.log(`Got ${smallBatch.length} transactions with custom count`);

  // Example 3: Get older transactions using older_id
  if (recentTransactions.length > 0) {
    const oldestTransaction = recentTransactions[recentTransactions.length - 1];
    const olderTransactions = await account.getTransactions({
      count: 50,
      older_id: oldestTransaction.id
    });
    console.log(`Got ${olderTransactions.length} older transactions`);
  }

  // Example 4: Get newer transactions using newer_id
  if (recentTransactions.length > 0) {
    const newestTransaction = recentTransactions[0];
    const newerTransactions = await account.getTransactions({
      count: 20,
      newer_id: newestTransaction.id
    });
    console.log(`Got ${newerTransactions.length} newer transactions`);
  }

  // Example 5: Backward compatibility - using number as newer_id
  const backwardCompatible = await account.getTransactions(12345);
  console.log(`Backward compatible call returned ${backwardCompatible.length} transactions`);

  // Example 6: Paginating through all historical transactions
  async function getAllTransactions(account: any): Promise<any[]> {
    const allTransactions: any[] = [];
    let lastTransactionId: number | false = false;
    let hasMore = true;

    while (hasMore) {
      const options: IBunqPaginationOptions = {
        count: 200,
        older_id: lastTransactionId
      };
      
      const batch = await account.getTransactions(options);
      
      if (batch.length === 0) {
        hasMore = false;
      } else {
        allTransactions.push(...batch);
        lastTransactionId = batch[batch.length - 1].id;
        console.log(`Fetched ${batch.length} transactions, total: ${allTransactions.length}`);
      }
    }

    return allTransactions;
  }

  // Example 7: Getting transactions between two dates
  async function getTransactionsBetweenDates(
    account: any,
    startDate: Date,
    endDate: Date
  ): Promise<any[]> {
    const transactions: any[] = [];
    let olderId: number | false = false;
    let keepFetching = true;

    while (keepFetching) {
      const batch = await account.getTransactions({
        count: 200,
        older_id: olderId
      });

      if (batch.length === 0) {
        keepFetching = false;
        break;
      }

      for (const transaction of batch) {
        const transactionDate = new Date(transaction.created);
        
        if (transactionDate >= startDate && transactionDate <= endDate) {
          transactions.push(transaction);
        } else if (transactionDate < startDate) {
          // We've gone past our date range
          keepFetching = false;
          break;
        }
      }

      olderId = batch[batch.length - 1].id;
    }

    return transactions;
  }

  // Usage
  const lastMonth = new Date();
  lastMonth.setMonth(lastMonth.getMonth() - 1);
  const transactionsLastMonth = await getTransactionsBetweenDates(
    account,
    lastMonth,
    new Date()
  );
  console.log(`Found ${transactionsLastMonth.length} transactions in the last month`);
}

// Run the demo
demonstratePagination().catch(console.error);