Add more tenant key generators (#36)

* Add RandomHexGenerator, create new namespace

* phpstan ignore

* add base64 generator

* add note about base64 being case sensitive

* docblock updates

* replace old UUIDGenerator with a class that throws an exception

* replace base64 generator with a random string generator

* Fix namespace

* Fix code style (php-cs-fixer)

* add test for the deprecated uuid generator

* update comments

---------

Co-authored-by: PHP CS Fixer <phpcsfixer@example.com>

src/UniqueIdentifierGenerators/RandomHexGenerator.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\UniqueIdentifierGenerators;
+
+use Illuminate\Database\Eloquent\Model;
+use Stancl\Tenancy\Contracts\UniqueIdentifierGenerator;
+
+/**
+ * Generates a cryptographically secure random hex string for the tenant key.
+ *
+ * To customize the byte length, change the static `bytes` property.
+ * The produced string length is 2 * byte length.
+ * The number of unique combinations is 2 ^ (8 * byte length).
+ */
+class RandomHexGenerator implements UniqueIdentifierGenerator
+{
+    public static int $bytes = 6;
+
+    public static function generate(Model $model): string
+    {
+        return bin2hex(random_bytes(static::$bytes));
+    }
+}

src/UniqueIdentifierGenerators/RandomStringGenerator.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\UniqueIdentifierGenerators;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Str;
+use Stancl\Tenancy\Contracts\UniqueIdentifierGenerator;
+
+/**
+ * Generates a cryptographically secure random string for the tenant key.
+ *
+ * To customize the string length, change the static `$length` property.
+ * The number of unique combinations is 36 ^ string length.
+ */
+class RandomStringGenerator implements UniqueIdentifierGenerator
+{
+    public static int $length = 8;
+
+    public static function generate(Model $model): string
+    {
+        return Str::random(static::$length);
+    }
+}

src/UniqueIdentifierGenerators/UUIDGenerator.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\UniqueIdentifierGenerators;
+
+use Illuminate\Database\Eloquent\Model;
+use Ramsey\Uuid\Uuid;
+use Stancl\Tenancy\Contracts\UniqueIdentifierGenerator;
+
+/**
+ * Generates a UUID for the tenant key.
+ */
+class UUIDGenerator implements UniqueIdentifierGenerator
+{
+    public static function generate(Model $model): string
+    {
+        return Uuid::uuid4()->toString();
+    }
+}