Upgrade translation mechanism

Currently, defining translations is quite cumbersome, and the translator
callback is passed to the constructor of multiple classes, which makes
it quite ugly and could make translations inconsistent.

This commit completely changes how translations are done in Validation.
Instead of using a callback, it uses a specific class, and `Validator`
will pass that object through the objects that render the messages.

docs/04-message-translation.md

@@ -1,17 +1,52 @@
 # Message translation
 
-You're also able to translate your message to another language with Validation.
-The only thing one must do is to define the param `translator` as a callable that
-will handle the translation overwriting the default factory:
+You're able to translate message templates with Validation.
 
 ```php
-Factory::setDefaultInstance(
-    (new Factory())->withTranslator('gettext')
-);
+use Respect\Validation\Message\Translator\GettextTranslator;
+use Respect\Validation\ValidatorDefaults;
+
+ValidatorDefaults::setTranslator(new GettextTranslator());
+```
+
+After that, if you call the methods `getMessage()`, `getMessages()`, or `getFullMessage()` from the `ValidationException`, the messages will be translated. The example above will work if you have `gettext` properly configured.
+
+For non-static usage, pass the translator directly to the `Validator` constructor:
+
+```php
+use Respect\Validation\Factory;
+use Respect\Validation\Message\StandardFormatter;
+use Respect\Validation\Message\Translator\GettextTranslator;
+use Respect\Validation\Validator;
+
+$translator = new GettextTranslator();
+
+$validator = new Validator(new Factory(), new StandardFormatter(), $translator);
 ```
 
-The example above uses `gettext()` but you can use any other callable value, like
-`[$translator, 'trans']` or `you_custom_function()`.
+## Supported translators
 
-After that, if you call `getMessage()`, `getMessages()`, or `getFullMessage()`,
-the message will be translated.
+- `ArrayTranslator`: Translates messages using an array of messages.
+- `GettextTranslator`: Translates messages using the `gettext` extension.
+
+## Custom translators
+
+You can implement custom translators by creating a class that implements the `Translator` interface. Here's an example using the `stichoza/google-translate-php` package:
+
+```php
+use Respect\Validation\Message\Translator;
+use Stichoza\GoogleTranslate\GoogleTranslate;
+
+final class MyTranslator implements Translator
+{
+    public function __construct(
+        private readonly GoogleTranslate $googleTranslate
+    ) {
+    }
+
+    public function translate(string $message): string
+    {
+        return $this->googleTranslate->translate($message);
+    }
+}
+```

library/Factory.php

@@ -13,10 +13,6 @@
 use ReflectionException;
 use Respect\Validation\Exceptions\ComponentException;
 use Respect\Validation\Exceptions\InvalidClassException;
-use Respect\Validation\Message\Parameter\Processor;
-use Respect\Validation\Message\Parameter\Raw;
-use Respect\Validation\Message\Parameter\Stringify;
-use Respect\Validation\Message\Parameter\Trans;
 use Respect\Validation\Transformers\Aliases;
 use Respect\Validation\Transformers\DeprecatedAge;
 use Respect\Validation\Transformers\DeprecatedAttribute;
@@ -42,22 +38,8 @@ final class Factory
      */
     private array $rulesNamespaces = ['Respect\\Validation\\Rules'];
 
-    /**
-     * @var callable
-     */
-    private $translator;
-
-    private Processor $processor;
-
-    private Transformer $transformer;
-
-    private static Factory $defaultInstance;
-
-    public function __construct()
-    {
-        $this->translator = static fn (string $message) => $message;
-        $this->processor = new Raw(new Trans($this->translator, new Stringify()));
-        $this->transformer = new DeprecatedAttribute(
+    public function __construct(
+        private readonly Transformer $transformer = new DeprecatedAttribute(
             new DeprecatedKey(
                 new DeprecatedKeyValue(
                     new DeprecatedMinAndMax(
@@ -67,16 +49,8 @@ public function __construct()
                     )
                 )
             )
-        );
-    }
-
-    public static function getDefaultInstance(): self
-    {
-        if (!isset(self::$defaultInstance)) {
-            self::$defaultInstance = new self();
-        }
-
-        return self::$defaultInstance;
+        )
+    ) {
     }
 
     public function withRuleNamespace(string $rulesNamespace): self
@@ -87,33 +61,6 @@ public function withRuleNamespace(string $rulesNamespace): self
         return $clone;
     }
 
-    public function withTranslator(callable $translator): self
-    {
-        $clone = clone $this;
-        $clone->translator = $translator;
-        $clone->processor = new Raw(new Trans($translator, new Stringify()));
-
-        return $clone;
-    }
-
-    public function withParameterProcessor(Processor $processor): self
-    {
-        $clone = clone $this;
-        $clone->processor = $processor;
-
-        return $clone;
-    }
-
-    public function getTranslator(): callable
-    {
-        return $this->translator;
-    }
-
-    public function getParameterProcessor(): Processor
-    {
-        return $this->processor;
-    }
-
     /**
      * @param mixed[] $arguments
      */
@@ -122,11 +69,6 @@ public function rule(string $ruleName, array $arguments = []): Validatable
         return $this->createRuleSpec($this->transformer->transform(new RuleSpec($ruleName, $arguments)));
     }
 
-    public static function setDefaultInstance(self $defaultInstance): void
-    {
-        self::$defaultInstance = $defaultInstance;
-    }
-
     private function createRuleSpec(RuleSpec $ruleSpec): Validatable
     {
         $rule = $this->createRule($ruleSpec->name, $ruleSpec->arguments);

library/Message/Formatter.php

@@ -16,17 +16,17 @@ interface Formatter
     /**
      * @param array<string, mixed> $templates
      */
-    public function main(Result $result, array $templates): string;
+    public function main(Result $result, array $templates, Translator $translator): string;
 
     /**
      * @param array<string, mixed> $templates
      */
-    public function full(Result $result, array $templates, int $depth = 0): string;
+    public function full(Result $result, array $templates, Translator $translator, int $depth = 0): string;
 
     /**
      * @param array<string, mixed> $templates
      *
      * @return array<string, mixed>
      */
-    public function array(Result $result, array $templates): array;
+    public function array(Result $result, array $templates, Translator $translator): array;
 }

library/Message/Renderer.php

@@ -13,5 +13,5 @@
 
 interface Renderer
 {
-    public function render(Result $result, ?string $template = null): string;
+    public function render(Result $result, Translator $translator, ?string $template = null): string;
 }

library/Message/StandardFormatter.php

@@ -29,29 +29,29 @@
 final class StandardFormatter implements Formatter
 {
     public function __construct(
-        private readonly Renderer $renderer,
+        private readonly Renderer $renderer = new StandardRenderer(),
     ) {
     }
 
     /**
      * @param array<string, mixed> $templates
      */
-    public function main(Result $result, array $templates): string
+    public function main(Result $result, array $templates, Translator $translator): string
     {
         $selectedTemplates = $this->selectTemplates($result, $templates);
         if (!$this->isFinalTemplate($result, $selectedTemplates)) {
             foreach ($this->extractDeduplicatedChildren($result) as $child) {
-                return $this->main($child, $selectedTemplates);
+                return $this->main($child, $selectedTemplates, $translator);
             }
         }
 
-        return $this->renderer->render($this->getTemplated($result, $selectedTemplates));
+        return $this->renderer->render($this->getTemplated($result, $selectedTemplates), $translator);
     }
 
     /**
      * @param array<string, mixed> $templates
      */
-    public function full(Result $result, array $templates, int $depth = 0): string
+    public function full(Result $result, array $templates, Translator $translator, int $depth = 0): string
     {
         $selectedTemplates = $this->selectTemplates($result, $templates);
         $isFinalTemplate = $this->isFinalTemplate($result, $selectedTemplates);
@@ -62,14 +62,14 @@ public function full(Result $result, array $templates, int $depth = 0): string
             $rendered .= sprintf(
                 '%s- %s' . PHP_EOL,
                 $indentation,
-                $this->renderer->render($this->getTemplated($result, $selectedTemplates)),
+                $this->renderer->render($this->getTemplated($result, $selectedTemplates), $translator),
             );
             $depth++;
         }
 
         if (!$isFinalTemplate) {
             foreach ($this->extractDeduplicatedChildren($result) as $child) {
-                $rendered .= $this->full($child, $selectedTemplates, $depth);
+                $rendered .= $this->full($child, $selectedTemplates, $translator, $depth);
                 $rendered .= PHP_EOL;
             }
         }
@@ -82,17 +82,23 @@ public function full(Result $result, array $templates, int $depth = 0): string
      *
      * @return array<string, mixed>
      */
-    public function array(Result $result, array $templates): array
+    public function array(Result $result, array $templates, Translator $translator): array
     {
         $selectedTemplates = $this->selectTemplates($result, $templates);
         $deduplicatedChildren = $this->extractDeduplicatedChildren($result);
         if (count($deduplicatedChildren) === 0 || $this->isFinalTemplate($result, $selectedTemplates)) {
-            return [$result->id => $this->renderer->render($this->getTemplated($result, $selectedTemplates))];
+            return [
+                $result->id => $this->renderer->render($this->getTemplated($result, $selectedTemplates), $translator),
+            ];
         }
 
         $messages = [];
         foreach ($deduplicatedChildren as $child) {
-            $messages[$child->id] = $this->array($child, $this->selectTemplates($child, $selectedTemplates));
+            $messages[$child->id] = $this->array(
+                $child,
+                $this->selectTemplates($child, $selectedTemplates),
+                $translator
+            );
             if (count($messages[$child->id]) !== 1) {
                 continue;
             }
@@ -101,7 +107,9 @@ public function array(Result $result, array $templates): array
         }
 
         if (count($messages) > 1) {
-            $self = ['__root__' => $this->renderer->render($this->getTemplated($result, $selectedTemplates))];
+            $self = [
+                '__root__' => $this->renderer->render($this->getTemplated($result, $selectedTemplates), $translator),
+            ];
 
             return $self + $messages;
         }