feat: chat + message store

composer.json

@@ -39,6 +39,7 @@
         "symfony/dotenv": "^6.4 || ^7.1",
         "symfony/event-dispatcher": "^6.4 || ^7.1",
         "symfony/finder": "^6.4 || ^7.1",
+        "symfony/http-foundation": "^6.4 || ^7.1",
         "symfony/process": "^6.4 || ^7.1",
         "symfony/var-dumper": "^6.4 || ^7.1"
     },
@@ -50,7 +51,8 @@
         "mongodb/mongodb": "For using MongoDB Atlas as retrieval vector store.",
         "probots-io/pinecone-php": "For using the Pinecone as retrieval vector store.",
         "symfony/css-selector": "For using the YouTube transcription tool.",
-        "symfony/dom-crawler": "For using the YouTube transcription tool."
+        "symfony/dom-crawler": "For using the YouTube transcription tool.",
+        "symfony/http-foundation": "For using the SessionStore as message store."
     },
     "autoload": {
         "psr-4": {

examples/persistent-chat.php

@@ -0,0 +1,34 @@
+<?php
+
+use PhpLlm\LlmChain\Bridge\OpenAI\GPT;
+use PhpLlm\LlmChain\Bridge\OpenAI\PlatformFactory;
+use PhpLlm\LlmChain\Chain;
+use PhpLlm\LlmChain\Chat;
+use PhpLlm\LlmChain\Chat\MessageStore\InMemoryStore;
+use PhpLlm\LlmChain\Model\Message\Message;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+use Symfony\Component\Dotenv\Dotenv;
+
+require_once dirname(__DIR__).'/vendor/autoload.php';
+(new Dotenv())->loadEnv(dirname(__DIR__).'/.env');
+
+if (empty($_ENV['OPENAI_API_KEY'])) {
+    echo 'Please set the OPENAI_API_KEY environment variable.'.PHP_EOL;
+    exit(1);
+}
+
+$platform = PlatformFactory::create($_ENV['OPENAI_API_KEY']);
+$llm = new GPT(GPT::GPT_4O_MINI);
+
+$chain = new Chain($platform, $llm);
+$chat = new Chat($chain, new InMemoryStore());
+
+$messages = new MessageBag(
+    Message::forSystem('You are a helpful assistant. You only answer with short sentences.'),
+);
+
+$chat->start($messages);
+$chat->submit(Message::ofUser('My name is Christopher.'));
+$message = $chat->submit(Message::ofUser('What is my name?'));
+
+echo $message->content.PHP_EOL;

src/Chat.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain;
+
+use PhpLlm\LlmChain\Chat\MessageStoreInterface;
+use PhpLlm\LlmChain\Model\Message\AssistantMessage;
+use PhpLlm\LlmChain\Model\Message\Message;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+use PhpLlm\LlmChain\Model\Message\UserMessage;
+use PhpLlm\LlmChain\Model\Response\TextResponse;
+
+final readonly class Chat implements ChatInterface
+{
+    public function __construct(
+        private ChainInterface $chain,
+        private MessageStoreInterface $store,
+    ) {
+    }
+
+    public function start(MessageBag $messages): void
+    {
+        $this->store->clear();
+        $this->store->save($messages);
+    }
+
+    public function submit(UserMessage $message): AssistantMessage
+    {
+        $messages = $this->store->load();
+
+        $messages->add($message);
+        $response = $this->chain->call($messages);
+
+        assert($response instanceof TextResponse);
+
+        $assistantMessage = Message::ofAssistant($response->getContent());
+        $messages->add($assistantMessage);
+
+        $this->store->save($messages);
+
+        return $assistantMessage;
+    }
+}

src/Chat/MessageStore/InMemoryStore.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Chat\MessageStore;
+
+use PhpLlm\LlmChain\Chat\MessageStoreInterface;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+
+final class InMemoryStore implements MessageStoreInterface
+{
+    private MessageBag $messages;
+
+    public function save(MessageBag $messages): void
+    {
+        $this->messages = $messages;
+    }
+
+    public function load(): MessageBag
+    {
+        return $this->messages ?? new MessageBag();
+    }
+
+    public function clear(): void
+    {
+        $this->messages = new MessageBag();
+    }
+}

src/Chat/MessageStore/SessionStore.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Chat\MessageStore;
+
+use PhpLlm\LlmChain\Chat\MessageStoreInterface;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
+
+final readonly class SessionStore implements MessageStoreInterface
+{
+    private SessionInterface $session;
+
+    public function __construct(
+        RequestStack $requestStack,
+        private string $sessionKey = 'messages',
+    ) {
+        $this->session = $requestStack->getSession();
+    }
+
+    public function save(MessageBag $messages): void
+    {
+        $this->session->set($this->sessionKey, $messages);
+    }
+
+    public function load(): MessageBag
+    {
+        return $this->session->get($this->sessionKey, new MessageBag());
+    }
+
+    public function clear(): void
+    {
+        $this->session->remove($this->sessionKey);
+    }
+}

src/Chat/MessageStoreInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain\Chat;
+
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+
+interface MessageStoreInterface
+{
+    public function save(MessageBag $messages): void;
+
+    public function load(): MessageBag;
+
+    public function clear(): void;
+}

src/ChatInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpLlm\LlmChain;
+
+use PhpLlm\LlmChain\Model\Message\AssistantMessage;
+use PhpLlm\LlmChain\Model\Message\MessageBag;
+use PhpLlm\LlmChain\Model\Message\UserMessage;
+
+interface ChatInterface
+{
+    public function start(MessageBag $messages): void;
+
+    public function submit(UserMessage $message): AssistantMessage;
+}