BillTracker/routes/matches.cts

// Fully type-checked (tsconfig.server.json); leading import type keeps Node type-stripping active.
import type { Req, Res, Next } from '../types/http';
const router = require('express').Router();
const { getDb } = require('../db/database.cts');
const {
  ApiError,
  ValidationError,
  NotFoundError,
  ConflictError,
} = require('../utils/apiError.cts');
const {
  applyBankPaymentAsSourceOfTruth,
  reactivatePaymentsOverriddenBy,
} = require('../services/paymentAccountingService.cts');
const {
  listMatchSuggestions,
  rejectMatchSuggestion,
} = require('../services/matchSuggestionService.cts');
const { learnMerchantRuleFromMatch } = require('../services/billMerchantRuleService.cts');
const { markMatched, markUnmatched } = require('../services/transactionMatchState.cts');
const { serializePayment } = require('../services/paymentValidation.cts');
const { todayLocal } = require('../utils/dates.mts');

// 4xx service errors keep their message/code on the wire; anything else is
// rethrown raw so the terminal handler masks + logs it as a 5xx.
function toMatchError(err: any) {
  if (err.status && err.status < 500) {
    return new ApiError(err.code || 'MATCH_ERROR', err.message, err.status, { field: err.field });
  }
  return err;
}

// GET /api/matches/suggestions
router.get('/suggestions', (req: Req, res: Res) => {
  res.json(listMatchSuggestions(req.user.id, req.query));
});

// POST /api/matches/:id/reject
router.post('/:id/reject', (req: Req, res: Res) => {
  res.json(rejectMatchSuggestion(req.user.id, req.params.id));
});

// POST /api/matches/confirm — link a transaction to a bill and record a payment
router.post('/confirm', (req: Req, res: Res) => {
  const txId = parseInt(req.body?.transaction_id, 10);
  const billId = parseInt(req.body?.bill_id, 10);
  if (!Number.isInteger(txId) || !Number.isInteger(billId)) {
    throw ValidationError('transaction_id and bill_id are required integers');
  }

  const db = getDb();
  const tx = db
    .prepare('SELECT * FROM transactions WHERE id = ? AND user_id = ?')
    .get(txId, req.user.id);
  if (!tx) throw NotFoundError('Transaction not found', 'transaction_id');
  if (tx.match_status === 'matched') {
    throw ConflictError(
      'Transaction is already matched to a bill',
      'transaction_id',
      'ALREADY_MATCHED',
    );
  }

  const bill = db
    .prepare('SELECT * FROM bills WHERE id = ? AND user_id = ? AND deleted_at IS NULL')
    .get(billId, req.user.id);
  if (!bill) throw NotFoundError('Bill not found', 'bill_id');

  const existing = db
    .prepare('SELECT id FROM payments WHERE transaction_id = ? AND deleted_at IS NULL')
    .get(txId);
  if (existing)
    throw ConflictError(
      'A payment is already linked to this transaction',
      undefined,
      'DUPLICATE_MATCH',
    );

  const paidDate =
    tx.posted_date || (tx.transacted_at ? tx.transacted_at.slice(0, 10) : todayLocal());
  const amount = Math.round(Math.abs(tx.amount)); // tx.amount and payments.amount are both cents

  try {
    db.exec('BEGIN');
    const payResult = db
      .prepare(
        "INSERT INTO payments (bill_id, amount, paid_date, payment_source, transaction_id) VALUES (?, ?, ?, 'transaction_match', ?)",
      )
      .run(billId, amount, paidDate, txId);

    const paymentForAccounting = db
      .prepare('SELECT * FROM payments WHERE id = ?')
      .get(payResult.lastInsertRowid);
    applyBankPaymentAsSourceOfTruth(db, bill, paymentForAccounting);

    markMatched(db, req.user.id, txId, billId);

    // Learn a merchant→bill rule from this explicit confirmation so future
    // synced transactions from the same merchant auto-match. Best-effort.
    learnMerchantRuleFromMatch(db, req.user.id, billId, tx);

    db.exec('COMMIT');

    const payment = db
      .prepare('SELECT * FROM payments WHERE id = ?')
      .get(payResult.lastInsertRowid);
    const updated = db
      .prepare(
        `
      SELECT t.*, b.name AS matched_bill_name
      FROM transactions t
      LEFT JOIN bills b ON b.id = t.matched_bill_id AND b.deleted_at IS NULL
      WHERE t.id = ?
    `,
      )
      .get(txId);
    res.json({ transaction: updated, payment: serializePayment(payment) });
  } catch (err) {
    try {
      db.exec('ROLLBACK');
    } catch {}
    throw toMatchError(err);
  }
});

// POST /api/matches/:transactionId/unmatch — remove a manual match
router.post('/:transactionId/unmatch', (req: Req, res: Res) => {
  const txId = parseInt(req.params.transactionId, 10);
  if (!Number.isInteger(txId)) {
    throw ValidationError('transactionId must be an integer');
  }

  const db = getDb();
  const tx = db
    .prepare('SELECT * FROM transactions WHERE id = ? AND user_id = ?')
    .get(txId, req.user.id);
  if (!tx) throw NotFoundError('Transaction not found');
  if (tx.match_status !== 'matched') {
    throw ConflictError('Transaction is not matched', undefined, 'NOT_MATCHED');
  }

  try {
    db.exec('BEGIN');
    const matchedPayments = db
      .prepare(
        `
      SELECT *
      FROM payments
      WHERE transaction_id = ? AND payment_source = 'transaction_match' AND deleted_at IS NULL
    `,
      )
      .all(txId);
    for (const payment of matchedPayments) {
      reactivatePaymentsOverriddenBy(db, payment.id);
    }
    db.prepare(
      `
      UPDATE payments SET deleted_at = datetime('now'), updated_at = datetime('now')
      WHERE transaction_id = ? AND payment_source = 'transaction_match' AND deleted_at IS NULL
    `,
    ).run(txId);
    markUnmatched(db, req.user.id, txId);
    db.exec('COMMIT');
    res.json({ ok: true });
  } catch (err) {
    try {
      db.exec('ROLLBACK');
    } catch {}
    throw toMatchError(err);
  }
});

module.exports = router;