The loop goes through several times, where is the error?

Question

PHP

There is an API code

<?php
$cache_ttl = 21600; // время жизни кэша в секундах
$cache_file_airlines = "tmp/ish.data";
$cache_file_products = "tmp/ish1.data";
$map = function ($array, $from, $to)
{
$result = [];
if (!empty($array) && is_array($array))
{
foreach ($array as $element)
{
$key = $element[$from] ? : null;
$value = $element[$to] ? : null;
if ($key && $value)
{
$result[$key] = $value;
}
}
}
return $result;
};
if (file_exists($cache_file_airlines) && (time() - filemtime($cache_file_airlines)) < $cache_ttl)
{
// берём кэшированные данные
$get_airlines = file_get_contents($cache_file_airlines);
}
else
{
$get_airlines = file_get_contents('https://site.ru/json/airlines.json');
file_put_contents($cache_file_airlines, $get_airlines);
}
$airlines = array_column($data, 'name','iata');

if (file_exists($cache_file_products) && (time() - filemtime($cache_file_products)) < $cache_ttl)
{
// берём кэшированные данные
$response = file_get_contents($cache_file_products);
}
else
{
$ch = curl_init();
curl_setopt(
  $ch,
  CURLOPT_URL,
  "https://api.travelpayouts.com/aviasales/v3/prices_for_dates?origin=MOW&destination=AER&token=****&departure_at=" . date('Y-m-d') );
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
"X-Access-Token: *****"
));
$response = curl_exec($ch);
curl_close($ch);

file_put_contents($cache_file_products, $response);
}
$products = json_decode($response, true);
$replace_value = function ($key, $val) use ($airlines)
{
$response = $val;
switch ($key)
{
case 'airline':
$response = $airlines[$val];
break;
}
return $response;
} ?>
 <div id="sochi" class="container" style="margin-top: 20px;">
<div style="margin: 0px auto;padding: 10px;text-align: center;"><h2>Билеты из Москвы в Адлер</h2><br><span style="font-size: 15px!important; font-weight: 400; color: #777777!important; font-weight: 300;"></span>
</div>
<div class="table-responsive" style="overflow-x:hidden;background: var(--responsiv-color)!important; display: flex; flex-direction: column; width: 100%;margin-left: auto; margin-right: auto; list-style-type: none;overflow-y:hidden;">

<?php
if (isset($products['data']) && is_array($products['data']))
{
foreach ($products['data'] as $key => $data)
{
foreach ($data as $destination => $key)
{
if (preg_match('/[A-Z]{3}/i', $key))
{
?>
<ul class="ticket">
    <li class="tickets_name"><p style="color:black;">Москва Сочи (Адлер)</p> <span class="tickets_span">Рейс: <?=$data['flight_number'] ?>  MOW-AER</span></li>
<li class="li"><p><img width="100" height="50" alt="авиакомпания на рейс Москва - Адлер" src="//img.io/100/40/<?=$data['airline'] ?>.jpg" class="lazyload air"/></p><span class="tickets_span"> Количество пересадок: <?=$data['transfers'] ?></span></li>
<li class="li_span"><p style="color:black;"><?php echo $replace_value('departure_at', substr($data['departure_at'], 0, 10)); ?></p><span class="tickets_span">Туда</span></li>
<a class="tickets_link" rel="nofollow" role="button" alt="авиабилеты Москва <?php echo $replace_value('destination', $key); ?>" title="Москва <?php echo $replace_value('destination', $key); ?>" href="https://site.ru/flights/?origin_iata=MOW&destination_iata=<?=$data['destination'] ?>&depart_date=<?=substr($data['departure_at'], 0, 10) ?>&marker=87111&with_request=true&search_id=<?=$data['search_id']?>&signature=<?=$data['signature']?>"><li>Билеты от <?php echo $replace_value('price', $data['price']); ?> р. </li></a>
</ul>
<?php
}
}
}
}
?>

When you go to the request link, you can see the following response

{"success":true,"data":[{"origin":"MOW","destination":"AER","price":2699,"airline":"DP","flight_number":"121","departure_at":"2021-07-21T14:35:00+03:00","search_id":"324813fa-a7a3-4acc-b321-285767bca79b","signature":"f6afb19d9382744abec928d70c224e3a","transfers":0,"return_transfers":0}],"currency":"rub"}

And after executing this loop

<?php
if (isset($products['data']) && is_array($products['data']))
{
foreach ($products['data'] as $key => $data)
{
foreach ($data as $destination => $key)
{
if (preg_match('/[A-Z]{3}/i', $key))
{
?>

Duplicate answers appear, maybe 4.5, 3 answers and all are the same.

The cycle is broken, I can't figure it out

Answer 1

Judging by your JSON received from the service, you do not need two foreach loops, the second one is superfluous, you can simply delete it.

Answer 2

you will have at least 2 pregmatch strings, in your case "origin": " MOW ", "destination": " AER ", so there will most likely always be duplicates.