<?php

require_once __DIR__ . '/db.php';
require_once __DIR__ . '/transaction_service.php';

function apply_recurring_transactions_for_month(int $userId, string $ym, bool $skipDuplicates = true): int
{
    $pdo = db();

    $stmt = $pdo->prepare("
        SELECT *
        FROM recurring_transactions
        WHERE user_id = ?
          AND is_active = 1
          AND (last_applied_ym IS NULL OR last_applied_ym <> ?)
        ORDER BY id ASC
    ");
    $stmt->execute([$userId, $ym]);
    $items = $stmt->fetchAll();

    $count = 0;
    $lastDay = (int)date('t', strtotime($ym . '-01'));

    foreach ($items as $item) {
        $day = min((int)$item['day_of_month'], $lastDay);
        $date = sprintf('%s-%02d', $ym, $day);

        $inserted = create_transaction([
            'user_id' => $userId,
            'account_id' => (int)$item['account_id'],
            'category_id' => (int)$item['category_id'],
            'transaction_type' => $item['transaction_type'],
            'amount' => (float)$item['amount'],
            'transaction_date' => $date,
            'merchant_name' => $item['merchant_name'],
            'description' => $item['description'],
            'related_account_id' => $item['related_account_id'] ? (int)$item['related_account_id'] : null,
        ], $skipDuplicates);

        $stmt2 = $pdo->prepare("UPDATE recurring_transactions SET last_applied_ym = ? WHERE id = ?");
        $stmt2->execute([$ym, $item['id']]);

        if ($inserted) {
            $count++;
        }
    }

    return $count;
}