<?php

declare(strict_types=1);

function json_response(array $payload, int $status = 200): void
{
    http_response_code($status);
    header('Content-Type: application/json');
    echo json_encode($payload);
    exit;
}

function read_json_body(): array
{
    $raw = file_get_contents('php://input');
    if ($raw === false || $raw === '') {
        return [];
    }

    $decoded = json_decode($raw, true);
    if (!is_array($decoded)) {
        json_response(['error' => 'Invalid JSON body'], 400);
    }

    return $decoded;
}

function require_business_date(?string $value): string
{
    if (!$value || !preg_match('/^\d{4}-\d{2}-\d{2}$/', $value)) {
        json_response(['error' => 'businessDate must be YYYY-MM-DD'], 400);
    }

    return $value;
}