prepare("
SELECT
i.*,
a.account_name,
a.institution_name,
t.transaction_date,
t.merchant_name,
t.description,
COALESCE(SUM(CASE WHEN s.is_billed = 0 THEN s.principal_amount ELSE 0 END), 0) AS remaining_principal,
COALESCE(SUM(CASE WHEN s.is_billed = 0 THEN s.interest_amount ELSE 0 END), 0) AS remaining_interest,
COALESCE(SUM(CASE WHEN s.is_billed = 0 THEN s.total_amount ELSE 0 END), 0) AS remaining_total,
COALESCE(SUM(CASE WHEN s.is_billed = 1 THEN s.total_amount ELSE 0 END), 0) AS billed_total,
COALESCE(MIN(CASE WHEN s.is_billed = 0 THEN s.cycle_no ELSE NULL END), 0) AS next_cycle
FROM installments i
JOIN accounts a ON a.id = i.account_id
JOIN transactions t ON t.id = i.transaction_id
LEFT JOIN installment_schedules s ON s.installment_id = i.id
WHERE i.id = ?
AND i.user_id = ?
GROUP BY
i.id, i.user_id, i.transaction_id, i.account_id,
i.principal_amount, i.interest_total, i.total_billed_amount,
i.installment_months, i.annual_interest_rate, i.start_year_month,
i.interest_type, i.current_cycle, i.is_completed,
i.prepaid_principal_amount, i.prepaid_interest_amount,
i.created_at, i.updated_at,
a.account_name, a.institution_name,
t.transaction_date, t.merchant_name, t.description
");
$stmt->execute([$installmentId, $uid]);
$installment = $stmt->fetch();
if (!$installment) {
require __DIR__ . '/../app/views/header.php';
?>