Create tool (call) normalizers for Responses API

Since we're migration from chat completions to Responses, which has a
differnt data structure for function calls

Author: paulinevos

src/platform/src/Bridge/OpenAi/Contract/Gpt/ToolCallNormalizer.php

@@ -0,0 +1,50 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Bridge\OpenAi\Contract\Gpt;
+
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt;
+use Symfony\AI\Platform\Contract\Normalizer\ModelContractNormalizer;
+use Symfony\AI\Platform\Model;
+use Symfony\AI\Platform\Result\ToolCall;
+
+final class ToolCallNormalizer extends ModelContractNormalizer
+{
+    /**
+     * @param ToolCall $data
+     *
+     * @return array{
+     *     arguments: string,
+     *     call_id: string,
+     *     name: string,
+     *     type: 'function_call'
+     * }
+     */
+    public function normalize(mixed $data, ?string $format = null, array $context = []): array
+    {
+        return [
+            'arguments' => json_encode($data->getArguments()),
+            'call_id' => $data->getId(),
+            'name' => $data->getName(),
+            'type' => 'function_call',
+        ];
+    }
+
+    protected function supportedDataClass(): string
+    {
+        return ToolCall::class;
+    }
+
+    protected function supportsModel(Model $model): bool
+    {
+        return $model instanceof Gpt;
+    }
+}

src/platform/src/Bridge/OpenAi/Contract/Gpt/ToolNormalizer.php

@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Platform\Bridge\OpenAi\Contract\Gpt;
+
+use Symfony\AI\Platform\Bridge\OpenAi\Gpt;
+use Symfony\AI\Platform\Contract\JsonSchema\Factory;
+use Symfony\AI\Platform\Contract\Normalizer\ModelContractNormalizer;
+use Symfony\AI\Platform\Model;
+use Symfony\AI\Platform\Tool\Tool;
+
+/**
+ * @phpstan-import-type JsonSchema from Factory
+ *
+ * @author Christopher Hertel <[email protected]>
+ */
+class ToolNormalizer extends ModelContractNormalizer
+{
+    public function supportsNormalization(mixed $data, ?string $format = null, array $context = []): bool
+    {
+        return $data instanceof Tool;
+    }
+
+    /**
+     * @param Tool $data
+     *
+     * @return array{
+     *     type: 'function',
+     *     name: string,
+     *     description: string,
+     *     parameters?: JsonSchema
+     * }
+     */
+    public function normalize(mixed $data, ?string $format = null, array $context = []): array
+    {
+        $function = [
+            'type' => 'function',
+            'name' => $data->getName(),
+            'description' => $data->getDescription(),
+        ];
+
+        if (null !== $data->getParameters()) {
+            $function['parameters'] = $data->getParameters();
+        }
+
+        return $function;
+    }
+
+    protected function supportedDataClass(): string
+    {
+        return Tool::class;
+    }
+
+    protected function supportsModel(Model $model): bool
+    {
+        return $model instanceof Gpt;
+    }
+}