Mon bouton supprime ne supprime pas et ça function non pu !

<?php

    if(admin()!=1){
        header("Location:index.php?page=dashboard");
    }

    // post func get
    $post = get_post();
    if($post == false){
        header("Location:index.php?page=error");
    } 


?>
</div>
    <div class="parallax-container">
        <div class="parallax">
            <img src="../img/posts/<?= $post->image ?>" alt="<?= $post->title ?>"/>
        </div>
    </div>
<div class="container">

    <?php
        // si submite press
        if(isset($_POST['submit'])){
            $title = htmlspecialchars(trim($_POST['title']));
            $content = htmlspecialchars(trim($_POST['content']));
            $posted = isset($_POST['public']) ? "1" : "0";
            $errors = [];

            // si vide
            if(empty($title) || empty($content)){
                $errors['empty'] = "Veuillez remplir tous les champs";
            }

            if(!empty($errors)){
                ?>
                <div class="card red">
                    <div class="card-content white-text">
                        <?php
                        foreach($errors as $error){
                            echo $error."<br/>";
                        }
                        ?>
                    </div>
                </div>
                <?php
            }else{
                // edite 
                edit($title,$content,$posted,$_GET['id']);
                if(isset($_POST['submit'])){
                          }
                ?>
                    <script>
                        // redirection
                        window.location.replace("index.php?page=post&id=<?= $_GET['id'] ?>");
                    </script>
                <?php
            }
    }
            
         // si supri et press
         if(isset($_POST['supri'])) {
            delete($title,$content,$posted,$date,$image,$writer,$_GET['id']);
         }
    ?>




   <!-- contenue article-->
    <form method="post">
        <div class="row">
            <div class="input-field col s12">
                <input type="text" name="title" id="title" value="<?= $post->title ?>"/>
                <label for="title">Titre de l'article</label>
            </div>
            <div class="input-field col s12">
                <textarea id="content" name="content" class="materialize-textarea"><?= $post->content ?></textarea>
                <label for="content">Contenu de l'article</label>
            </div>

            <div class="col s6">
                <p>Public</p>
                <div class="switch">
                    <label>
                        Non
                        <input type="checkbox" name="public" <?php echo ($post->posted == "1")?"checked" : "" ?>/>
                        <span class="lever"></span>
                        Oui
                    </label>
                </div>
            </div>

            <div class="col s6 right-align">
                <br/><br/>
                 <!--boutton admin  sup-->
                 <button type="surpi" class="btn" name="supri" >Supprime</button>
                 <!-- boutton modif -->
                 <button type="submit" class="btn" name="submit" >Modifier l'article</button>

            </div>

        </div>



    </form>

<?php

function get_post(){

    global $db;

    $req = $db->query("
        SELECT  posts.id,
                posts.title,
                posts.image,
                posts.date,
                posts.content,
                posts.posted,
                admins.name
        FROM posts
        JOIN admins
        ON posts.writer = admins.email
        WHERE posts.id = '{$_GET['id']}'
    ");

    $result = $req->fetchObject();
    return $result;
}

// Permet d'édit un article
function edit($title,$content,$posted,$id){

    // connexion a la bd
    global $db;

    // tableau pour la requête
    $e = [
        'title'     => $title,
        'content'   => $content,
        'posted'    => $posted,
        'id'        => $id
    ];

    // la requpete 
    $sql = "UPDATE posts SET title=:title, content=:content, date=NOW(),posted=:posted WHERE id=:id";
    $req = $db->prepare($sql);
    $req->execute($e);

}


// Permet delete un article
function delete($title,$content,$posted,$date,$image,$writer,$id){

    // connexion a la bd
    global $db;

    // tableau pour la requête
    $e = [
        'title'     => $title,
        'content'   => $content,
        'posted'    => $posted,
        'id'        => $id,
        'date'      => $date,
        'image'     => $image,
        'writer'    => $writer

    ];

    // la requpete 
    $sql = "DELETE FROM posts WHERE id=:id";
    $req = $db->prepare($sql);
    $req->execute($e);
}