<?php

namespace App\Classes\Tools;

interface DatabaseInterface
{
	public static function getInstance();

	public function getConnexion();
}

• src\Classes\Tools\Database.php

<?php

namespace App\Classes\Tools;

use App\Classes\Tools\DatabaseInterface;
use PDO;

class Database implements DatabaseInterface
{
    private static $instance = false;

    protected $connexion;

    private function __construct()
    {
        $this->connexion = new PDO(PDO_DSN, USER, PASSWD);
        $this->connexion->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }

    private function __clone()
    {
    }

    public static function getInstance()
    {
        if (self::$instance === false) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    public function getConnexion()
    {
        return $this->connexion;
    }
}

<?php

namespace App\Classes\Album;

use App\Classes\Tools\DatabaseInterface;
use App\Classes\Music\Music;
use PDO;

class Repository
{
    private $database;

    public function __construct(DatabaseInterface $database)
    {
        $this->database = $database;
    }

    public static function read($id)
    {
        $db = $this->database::getInstance()->getConnexion();
        $sth = $db->prepare('SELECT * FROM albums WHERE id=:id');

        $data = array('id' => $id);
        $sth->execute($data);
        $line = $sth->fetch(PDO::FETCH_ASSOC);

        return Album::initialize($line);
    }

    public static function getPlayList($id)
    {
        $db = $this->database::getInstance()->getConnexion();

        $sth = $db->prepare('SELECT * FROM songs WHERE id_album=:id_album');

        $data = array('id_album' => $id);

        $sth->execute($data);

        $lignes = $sth->fetchAll(PDO::FETCH_ASSOC);
        $musiques = array();
        foreach ($lignes as $ligne) {
            $musiques[] = Music::initialize($ligne);
        }

        return $musiques;
    }

    public static function new(Album $album)
    {
        $db = $this->database::getInstance()->getConnexion();
        $sth = $db->prepare('insert into albums set id=:id,title=:title, author=:author, file=:file, created_at=:created_at');

        $sth->execute([
            'id' => $album->getId(),
            'title' => $album->getTitle(),
            'author' => $album->getAuthor(),
            'created_at' => $album->getCreatedAt(),
            'file' => $album->getFile(),
        ]);
    }

    public static function update(Album $album)
    {
        $db = $this->database::getInstance()->getConnexion();

        $sth = $db->prepare('update albums set title=:title, author=:author, file=:file where id =:id');

        $sth->execute([
            'id' => $album->getId(),
            'title' => $album->getTitle(),
            'author' => $album->getAuthor(),
            'file' => $album->getFile(),
        ]);
    }

    public static function delete(Album $album)
    {
        $db = $this->database::getInstance()->getConnexion();
        $sth = $db->prepare('delete from albums where id=:id');

        $sth->execute(['id' => $album->getId()]);
    }

    public static function getListAlbums($limit)
    {
        $db = $this->database::getInstance()->getConnexion();

        $sth = $db->query("SELECT * FROM albums LIMIT $limit");

        $rawAlbums = $sth->fetchAll(PDO::FETCH_ASSOC);
        $albums = [];
        foreach ($rawAlbums as $rawAlbum) {
            $albums[] = Album::initialize($rawAlbum);
        }

        return $albums;
    }

    public static function getAllAlbums()
    {
        $db = $this->database::getInstance()->getConnexion();

        $sth = $db->query('SELECT * FROM albums');

        $rawAlbums = $sth->fetchAll(PDO::FETCH_ASSOC);
        $albums = [];
        foreach ($rawAlbums as $rawAlbum) {
            $albums[] = Album::initialize($rawAlbum);
        }

        return $albums;
    }
}

• src/public/index.php

<?php

require_once '../config/config.php';
require_once '../config/config_db.php';
require_once '../vendor/autoload.php';

use App\Classes\Album\Repository as AlbumRepository;
use App\Classes\Album\Collection as AlbumCollection;
use App\Controllers\PublicController;
use App\Classes\Tools\View;
use App\Classes\Album\Ui as AlbumUi;
use App\Classes\Music\Ui as MusicUi;

use App\Classes\Tools\Database;

// initialisation des variables
$title = '';
$c = '';
$header = file_get_contents('../ui/fragments/header.frg.html');
$footer = file_get_contents('../ui/fragments/footer.frg.html');
$skeleton = '../ui/pages/galerie.html.php';
$controller = new PublicController();
$database = Database::getInstance();

try {
    $getRequest = $_GET;
    $action = isset($getRequest['a']) ? $getRequest['a'] : '';

    switch ($action) {
        case 'ecouter':
            $title = "Ecoute de l'album";
            if (isset($getRequest['id'])) {
                $albumId = $getRequest['id'];
                $ListOfMusics = AlbumRepository($database)::getPlayList($albumId);
                if (count($ListOfMusics) == 0) {
                    $c = 'Album vide, Ajoutez des pistes';
                } else {
                    $i = 0;
                    foreach ($ListOfMusics as $Music) {
                        $ui = MusicUi::factory($Music);
                        if ($i < 1) {
                            $c = '<section id="album_view" class="span6">' . $ui->makePlayer();
                            $c .= '<ol>';

                            $c .= '<li class="playing">' . $ui->makeHtml() . '</li>';
                            $i = 1;
                        } else {
                            $c .= '<li>' . $ui->makeHtml() . '</li>';
                        }
                    }
                    $c .= '</ol></section>';
                }

                $album = AlbumRepository($database)::read($albumId);
                $albumUi = new AlbumUi($album);
                $c .= $albumUi->displayAlbumInfos();
            }
            break;

        case 'aide':
            return View::sendHttpResponse($controller->help());
            break;

        default:
            $title = 'Les derniers Albums enregistrés';
            $selectionOfAlbums = AlbumRepository($database)::getListAlbums(20);
            $selectionOfAlbums = new AlbumCollection($selectionOfAlbums);
            $c = $selectionOfAlbums->viewHtml();

            $allAlbums = AlbumRepository($database)::getAllAlbums();
            $allAlbums = new AlbumCollection($allAlbums);
            $c .= $allAlbums->viewTable();
    }
} catch (Exception $e) {
    $c = $e->getMessage();
    $c .= "<pre>{$e->getTraceAsString()}</pre>";
}

ob_start();
  require_once $skeleton;
  $html = ob_get_contents();
ob_end_clean();
echo $html;