Extract DatabaseConfig class with validation

src/Install/DatabaseConfig.php

@@ -0,0 +1,98 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Install;
+
+class DatabaseConfig
+{
+    private $driver;
+    private $host;
+    private $port;
+    private $database;
+    private $username;
+    private $password;
+    private $prefix;
+
+    public function __construct($driver, $host, $port, $database, $username, $password, $prefix)
+    {
+        $this->driver = $driver;
+        $this->host = $host;
+        $this->port = $port;
+        $this->database = $database;
+        $this->username = $username;
+        $this->password = $password;
+        $this->prefix = $prefix;
+
+        $this->validate();
+    }
+
+    public function getConfig(): array
+    {
+        return [
+            'driver'    => $this->driver,
+            'host'      => $this->host,
+            'port'      => $this->port,
+            'database'  => $this->database,
+            'username'  => $this->username,
+            'password'  => $this->password,
+            'charset'   => 'utf8mb4',
+            'collation' => 'utf8mb4_unicode_ci',
+            'prefix'    => $this->prefix,
+            'strict'    => false,
+            'engine'    => 'InnoDB',
+        ];
+    }
+
+    private function validate()
+    {
+        if (empty($this->driver)) {
+            throw new ValidationFailed('Please specify a database driver.');
+        }
+
+        if ($this->driver !== 'mysql') {
+            throw new ValidationFailed('Currently, only MySQL/MariaDB is supported.');
+        }
+
+        if (empty($this->host)) {
+            throw new ValidationFailed('Please specify the hostname of your database server.');
+        }
+
+        if (! is_int($this->port) || $this->port < 1 || $this->port > 65535) {
+            throw new ValidationFailed('Please provide a valid port number between 1 and 65535.');
+        }
+
+        if (empty($this->database)) {
+            throw new ValidationFailed('Please specify the database name.');
+        }
+
+        if (! is_string($this->database)) {
+            throw new ValidationFailed('The database name must be a non-empty string.');
+        }
+
+        if (empty($this->username)) {
+            throw new ValidationFailed('Please specify the username for accessing the database.');
+        }
+
+        if (! is_string($this->database)) {
+            throw new ValidationFailed('The username must be a non-empty string.');
+        }
+
+        if (! empty($this->prefix)) {
+            if (! preg_match('/^[\pL\pM\pN_-]+$/u', $this->prefix)) {
+                throw new ValidationFailed('The prefix may only contain characters, dashes and underscores.');
+            }
+
+            if (strlen($this->prefix) > 10) {
+                throw new ValidationFailed('The prefix should be no longer than 10 characters.');
+            }
+        }
+    }
+}