Get the position number of a file in the $_FILES array - php

Question

I have an image manager with preview and I need to know the position number of the image in the $_FILES array so I can know which one I have to delete and upload the new one. The images names are just numbers (i.e. 1.jpg, 2.jpg, etc).
For example, I have 6 images in preview (6 inputs) and I need to replace some of them so I click the remove buttom for those to replace and then I drag and drop the new ones. When I click upload I need to know how many inputs are filled with an image and the position of them in the $_FILES array so I don't delete the wrong ones.
If one of the previews are removed and are not replaced I have to delete the file from server, I'm thinking on using hidden inputs with a value of 0/1 to know if the user wants to remove the image, these values are set by the remove image button (each input have it's own). I'm having some trouble thinking how to get this done.
This is what I already have:
$file_count = count($_FILES['file']['tmp_name']);
$id = isset($_GET['id']) && $_GET['id'] != '' ? (int) $_GET['id'] : 0;
if ($id !== 0) {
$path = realpath('/home/aet/websites/images/property/' . $id . '/');
if ( FALSE !== $path && is_dir($path) ) {
$url = [];
for($i = 0; $i < $file_count; $i++) {
if ($_FILES['file']['name'][$i] != '') {
$path = $path . (++$i) . '.jpg';
if (file_exists($path)) unlink($path);
if (move_uploaded_file($file_count[$i], $path)) {
$url[] = 'http://static.website.com/images/property/' . $id . '/' . (++$i) . '.jpg';
} else die('Error uploading image (' . (++$i) . ')' );
} else {
// first we have to check if the user requested the file deletion
// (no image preview in the html)
//unlink($path);
}
}
if ( !empty($url) ) {
$mysqli = $staff->aet->getAetSql();
$mysqli->set_charset('utf8');
$mysqli->autocommit(FALSE);
$value = NULL;
if ($stmt = $mysqli->prepare('INSERT INTO img (path, property) VALUES (?, ?)')) {
$stmt->bind_param('si', $value, $id);
foreach ($url as $key => $value) {
$stmt->execute();
}
if ( $mysqli->commit() ) {
header('Location: /property');
} else die('DB Error.');
}
}
} else die('Error (path does not exist)');
}