general refactor, move more classes under Database namespace

src/Database/TenantDatabaseManagers/PostgreSQLDatabaseManager.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Database\TenantDatabaseManagers;
+
+use Illuminate\Database\Connection;
+use Illuminate\Support\Facades\DB;
+use Stancl\Tenancy\Database\Contracts\TenantDatabaseManager;
+use Stancl\Tenancy\Database\Contracts\TenantWithDatabase;
+use Stancl\Tenancy\Database\Exceptions\NoConnectionSetException;
+
+class PostgreSQLDatabaseManager implements TenantDatabaseManager
+{
+    /** @var string */
+    protected $connection;
+
+    protected function database(): Connection
+    {
+        if ($this->connection === null) {
+            throw new NoConnectionSetException(static::class);
+        }
+
+        return DB::connection($this->connection);
+    }
+
+    public function setConnection(string $connection): void
+    {
+        $this->connection = $connection;
+    }
+
+    public function createDatabase(TenantWithDatabase $tenant): bool
+    {
+        return $this->database()->statement("CREATE DATABASE \"{$tenant->database()->getName()}\" WITH TEMPLATE=template0");
+    }
+
+    public function deleteDatabase(TenantWithDatabase $tenant): bool
+    {
+        return $this->database()->statement("DROP DATABASE \"{$tenant->database()->getName()}\"");
+    }
+
+    public function databaseExists(string $name): bool
+    {
+        return (bool) $this->database()->select("SELECT datname FROM pg_database WHERE datname = '$name'");
+    }
+
+    public function makeConnectionConfig(array $baseConfig, string $databaseName): array
+    {
+        $baseConfig['database'] = $databaseName;
+
+        return $baseConfig;
+    }
+}