feat: Google structured output (#354)

Author: valtzu

examples/google/structured-output-clock.php

@@ -0,0 +1,50 @@
+<?php
+
+use PhpLlm\LlmChain\Chain\Chain;
+use PhpLlm\LlmChain\Chain\StructuredOutput\ChainProcessor as StructuredOutputProcessor;
+use PhpLlm\LlmChain\Chain\Toolbox\ChainProcessor as ToolProcessor;
+use PhpLlm\LlmChain\Chain\Toolbox\Tool\Clock;
+use PhpLlm\LlmChain\Chain\Toolbox\Toolbox;
+use PhpLlm\LlmChain\Platform\Bridge\Google\Gemini;
+use PhpLlm\LlmChain\Platform\Bridge\Google\PlatformFactory;
+use PhpLlm\LlmChain\Platform\Message\Message;
+use PhpLlm\LlmChain\Platform\Message\MessageBag;
+use Symfony\Component\Clock\Clock as SymfonyClock;
+use Symfony\Component\Dotenv\Dotenv;
+
+require_once dirname(__DIR__, 2).'/vendor/autoload.php';
+(new Dotenv())->loadEnv(dirname(__DIR__, 2).'/.env');
+
+if (empty($_ENV['GOOGLE_API_KEY'])) {
+    echo 'Please set the GOOGLE_API_KEY environment variable.'.\PHP_EOL;
+    exit(1);
+}
+
+$platform = PlatformFactory::create($_ENV['GOOGLE_API_KEY']);
+$model = new Gemini(Gemini::GEMINI_1_5_FLASH);
+
+$clock = new Clock(new SymfonyClock());
+$toolbox = Toolbox::create($clock);
+$toolProcessor = new ToolProcessor($toolbox);
+$structuredOutputProcessor = new StructuredOutputProcessor();
+$chain = new Chain($platform, $model, [$toolProcessor, $structuredOutputProcessor], [$toolProcessor, $structuredOutputProcessor]);
+
+$messages = new MessageBag(Message::ofUser('What date and time is it?'));
+$response = $chain->call($messages, ['response_format' => [
+    'type' => 'json_schema',
+    'json_schema' => [
+        'name' => 'clock',
+        'strict' => true,
+        'schema' => [
+            'type' => 'object',
+            'properties' => [
+                'date' => ['type' => 'string', 'description' => 'The current date in the format YYYY-MM-DD.'],
+                'time' => ['type' => 'string', 'description' => 'The current time in the format HH:MM:SS.'],
+            ],
+            'required' => ['date', 'time'],
+            'additionalProperties' => false,
+        ],
+    ],
+]]);
+
+dump($response->getContent());

examples/google/structured-output-math.php

@@ -0,0 +1,31 @@
+<?php
+
+use PhpLlm\LlmChain\Chain\Chain;
+use PhpLlm\LlmChain\Chain\StructuredOutput\ChainProcessor;
+use PhpLlm\LlmChain\Platform\Bridge\Google\Gemini;
+use PhpLlm\LlmChain\Platform\Bridge\Google\PlatformFactory;
+use PhpLlm\LlmChain\Platform\Message\Message;
+use PhpLlm\LlmChain\Platform\Message\MessageBag;
+use PhpLlm\LlmChain\Tests\Fixture\StructuredOutput\MathReasoning;
+use Symfony\Component\Dotenv\Dotenv;
+
+require_once dirname(__DIR__, 2).'/vendor/autoload.php';
+(new Dotenv())->loadEnv(dirname(__DIR__, 2).'/.env');
+
+if (empty($_ENV['GOOGLE_API_KEY'])) {
+    echo 'Please set the GOOGLE_API_KEY environment variable.'.\PHP_EOL;
+    exit(1);
+}
+
+$platform = PlatformFactory::create($_ENV['GOOGLE_API_KEY']);
+$model = new Gemini(Gemini::GEMINI_1_5_FLASH);
+
+$processor = new ChainProcessor();
+$chain = new Chain($platform, $model, [$processor], [$processor]);
+$messages = new MessageBag(
+    Message::forSystem('You are a helpful math tutor. Guide the user through the solution step by step.'),
+    Message::ofUser('how can I solve 8x + 7 = -23'),
+);
+$response = $chain->call($messages, ['output_structure' => MathReasoning::class]);
+
+dump($response->getContent());

src/Platform/Bridge/Google/Gemini.php

@@ -29,6 +29,7 @@ public function __construct(string $name = self::GEMINI_2_PRO, array $options =
             Capability::INPUT_AUDIO,
             Capability::INPUT_PDF,
             Capability::OUTPUT_STREAMING,
+            Capability::OUTPUT_STRUCTURED,
             Capability::TOOL_CALLING,
         ];
 

src/Platform/Bridge/Google/ModelHandler.php

@@ -54,6 +54,12 @@ public function request(Model $model, array|string $payload, array $options = []
             $options['stream'] ?? false ? 'streamGenerateContent' : 'generateContent',
         );
 
+        if (isset($options['response_format']['json_schema']['schema'])) {
+            $options['responseMimeType'] = 'application/json';
+            $options['responseJsonSchema'] = $options['response_format']['json_schema']['schema'];
+            unset($options['response_format']);
+        }
+
         $generationConfig = ['generationConfig' => $options];
         unset($generationConfig['generationConfig']['stream']);
         unset($generationConfig['generationConfig']['tools']);