<?php
header('Content-Type: application/json');
require_once __DIR__ . '/db/config.php';

$response = ['success' => false, 'error' => 'Invalid request'];

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $projectId = $_POST['projectId'] ?? null;
    $month = $_POST['month'] ?? null;
    $amount = $_POST['amount'] ?? null;

    if ($projectId && $month && $amount !== null) {
        try {
            $pdo = db();
            $stmt = $pdo->prepare("UPDATE expensesMonthly SET amount = :amount WHERE projectId = :projectId AND month = :month");
            $stmt->execute([
                ':amount' => $amount,
                ':projectId' => $projectId,
                ':month' => $month
            ]);

            if ($stmt->rowCount() > 0) {
                $response['success'] = true;
                unset($response['error']);
            } else {
                $response['error'] = 'No record found to update.';
            }
        } catch (PDOException $e) {
            $response['error'] = 'Database error: ' . $e->getMessage();
        }
    } else {
        $response['error'] = 'Missing required fields.';
    }
}

echo json_encode($response);