feat: implement CustomerSupport agent and add SendMessageRequest for chat handling

Author: estefanoquiriconi

app/Ai/Agents/CustomerSupport.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Ai\Agents;
+
+use Laravel\Ai\Attributes\Provider;
+use Laravel\Ai\Concerns\RemembersConversations;
+use Laravel\Ai\Contracts\Agent;
+use Laravel\Ai\Contracts\Conversational;
+use Laravel\Ai\Promptable;
+use Stringable;
+
+#[Provider('gemini')]
+class CustomerSupport implements Agent, Conversational
+{
+    use Promptable, RemembersConversations;
+
+    /**
+     * Get the instructions that the agent should follow.
+     */
+    public function instructions(): Stringable|string
+    {
+        return <<<'PROMPT'
+        You are a friendly and professional customer support agent. Your role is to:
+
+        - Answer customer questions clearly and concisely.
+        - Help resolve issues with empathy and patience.
+        - Escalate complex problems when you cannot resolve them directly.
+        - Always maintain a polite and helpful tone.
+
+        If you don't know the answer, be honest and suggest the customer contact a human agent for further assistance.
+        PROMPT;
+    }
+}

app/Http/Controllers/ChatController.php

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+<?php
+
+namespace App\Http\Controllers;
+
+use App\Ai\Agents\CustomerSupport;
+use App\Http\Requests\Chat\SendMessageRequest;
+use Generator;
+use Illuminate\Support\Facades\DB;
+use Laravel\Ai\Streaming\Events\TextDelta;
+use Symfony\Component\HttpFoundation\StreamedResponse;
+
+class ChatController extends Controller
+{
+    /**
+     * Stream a chat response from the CustomerSupport agent.
+     */
+    public function stream(SendMessageRequest $request): StreamedResponse
+    {
+        $user = $request->user();
+        $message = $request->validated('message');
+        $conversationId = $request->validated('conversation_id');
+
+        $agent = new CustomerSupport;
+
+        if ($conversationId) {
+            $conversationRecord = DB::table('agent_conversations')
+                ->where('id', $conversationId)
+                ->where('user_id', $user->id)
+                ->first();
+
+            abort_unless($conversationRecord, 403);
+
+            $stream = $agent->continue($conversationId, as: $user)->stream($message);
+        } else {
+            $stream = $agent->forUser($user)->stream($message);
+        }
+
+        return response()->stream(function () use ($stream): Generator {
+            foreach ($stream as $event) {
+                if ($event instanceof TextDelta) {
+                    yield $event->delta;
+                }
+            }
+
+            yield "\n<<conversation:{$stream->conversationId}>>";
+        });
+    }
+}

app/Http/Requests/Chat/SendMessageRequest.php

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+<?php
+
+namespace App\Http\Requests\Chat;
+
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Foundation\Http\FormRequest;
+
+class SendMessageRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'message' => ['required', 'string', 'max:5000'],
+            'conversation_id' => ['nullable', 'string', 'uuid'],
+        ];
+    }
+}