<?php

use App\Services\SiteDataService;

/**
 * Get or set site data values.
 *
 * When called without arguments, returns the SiteDataService instance.
 * When called with a key, retrieves the value for that key.
 * When called with a key and value, sets the value and returns it.
 *
 * @param  string|null  $key  The site data key to get or set
 * @param  mixed  $value  The value to set (optional)
 * @return mixed The SiteDataService instance, retrieved value, or set value
 *
 * @throws \InvalidArgumentException If the key is not defined in configuration
 *
 * @example
 * siteData() // Returns SiteDataService instance
 * siteData('concertClinicDates') // Returns the value
 * siteData('concertClinicDates', '2025-03-15') // Sets and returns the value
 */
function siteData(?string $key = null, mixed $value = null): mixed
{
    $dataService = app(SiteDataService::class);

    if (is_null($key)) {
        return $dataService;
    }

    if (func_num_args() === 1) {
        return $dataService->get($key);
    }

    $dataService->set($key, $value);

    return $value;
}