How you can enable particular extensions and file measurement to wp_mail attachment?

I’m making an attempt to create a type with an attachment possibility that might be despatched to an e-mail when the shape is submitted on a wordpress web site.

My codes work tremendous and it sends e-mail in a HTMKL desk format to my e-mail handle. Additionally I’m able to ship attachment utilizing the codes. The difficulty arises once I think about the attachment file extensions and file measurement. I have no idea that how one can limit massive measurement of recordsdata and set attachments for some allowed extensions solely.

My code is:

<?php
//Setup an empty array.
$errors = array(); 
    if($_POST["submit"]) {
    $to = "myemail@gmail.com";
    $topic = "New reservations request";
    $resort = $_POST["hotel_url"];
    $sender = $_POST["sendername"];
    $senderEmail = $_POST["senderEmail"];

    //Examine the identify and ensure that it is not a clean/empty string.
    if(empty($sender)){
        //Clean string, add error to $errors array.        
        $errors['sendername'] = "Please enter your identify!";
    }

    /*  attachment */   
    move_uploaded_file($_FILES["attachment"]["tmp_name"],WP_CONTENT_DIR .'/uploads/'.basename($_FILES['attachment']['name']));
    $attachments = array(WP_CONTENT_DIR ."/uploads/".$_FILES["attachment"]["name"]);    

    if(empty($errors)){

        $mailBody = "<desk border='1'>
                       <tr>
                        <th>No</td>
                        <th>Merchandise</td>
                        <th>Description</td>
                       </tr>
                       <tr>
                        <td>01</td>
                        <td>Lodge</td>
                        <td>$resort</td>
                       </tr>
                       <tr>
                        <td>02</td>
                        <td>Title</td>
                        <td>$sender</td>
                       </tr>
                       <tr>
                        <td>03</td>
                        <td>E-Mail</td>
                        <td>$senderEmail</td>
                       </tr>
                    </desk>";  

            $headers = array('From: '.$_POST['sendername'].' <'.$_POST['senderEmail'].'>');

            $mail_sent = wp_mail( $to, $topic, $mailBody, $headers, $attachments );   
        }
    }

    if ($mail_sent) {
?>
    <p>Request despatched</p>

<?php 
} else {
?>

<type id="" identify="" motion="<?php echo get_permalink(); ?>" methodology="submit" enctype="multipart/form-data">
<enter sort="hidden" identify="hotel_url" worth="<?php echo get_permalink();?>" />

    <div class="section-heading"><h6>Your Particulars</h6></div>    
    <div class="label-input-wrapper">
        <div class="form-label">Title</div>
        <div class="form-input">
            <enter sort="textual content" identify="sendername"/>
            <?php if(isset($errors['sendername'])) { echo '<span type="colour: pink">'.$errors['sendername'].'</span>'; } ?>
        </div>
    </div>

    <div class="label-input-wrapper">
        <div class="form-label">E-Mail</div>
            <div class="form-input">
                <enter sort="e-mail" identify="senderEmail" sample="[a-z0-9._%+-]+@[a-z0-9.-]+.[a-z]{2,4}$" required worth="<?PHP if(!empty($errors)) { echo $senderEmail;} ?>"/>
            </div>
    </div>  

    <label for='uploaded_file'>Choose A File To Add:</label>
    <enter sort="file" identify="attachment">

    <enter sort="submit" worth="Submit" identify="submit">
</type>

<?php
}
?>

The above code ship the attachment to my mail and it saves the file into my uploads dirctory.
I do know I’ve to do one thing round this space /* attachment */ to permit particular extensions and measurement of the file. however how to try this?
eg: if I’ve to permit .png, .jpg, .pdf solely and the utmost file is 1mb how can I do this? the place and what code I’ve to amend into the above codes?