brazil-swift-ops/packages/treasury/src/reporting.ts

import type {
  SubledgerReport,
  AccountPosting,
} from '@brazil-swift-ops/types';
import { getPostingStore } from './posting';
import { getAccountStore } from './accounts';

export function generateSubledgerReport(
  subledgerId: string,
  periodStart: Date,
  periodEnd: Date
): SubledgerReport {
  const accountStore = getAccountStore();
  const postingStore = getPostingStore();

  const subledger = accountStore.get(subledgerId);
  if (!subledger || subledger.type !== 'subledger') {
    throw new Error(`Subledger account ${subledgerId} not found`);
  }

  const postings = postingStore
    .getByAccount(subledgerId)
    .filter(
      (p) => p.postedAt >= periodStart && p.postedAt <= periodEnd
    );

  const openingBalance = subledger.balance - postings.reduce((sum, p) => {
    return p.postingType === 'debit' ? sum - p.amount : sum + p.amount;
  }, 0);

  const totalDebits = postings
    .filter((p) => p.postingType === 'debit')
    .reduce((sum, p) => sum + p.amount, 0);

  const totalCredits = postings
    .filter((p) => p.postingType === 'credit')
    .reduce((sum, p) => sum + p.amount, 0);

  const closingBalance = openingBalance + totalCredits - totalDebits;
  const netPosition = totalCredits - totalDebits;

  return {
    subledgerId,
    periodStart,
    periodEnd,
    openingBalance,
    closingBalance,
    totalDebits,
    totalCredits,
    netPosition,
    currency: subledger.currency,
    transactionCount: new Set(postings.map((p) => p.transactionId)).size,
    postings,
  };
}