ref #6: [feat] add impl in memory session repository

usecase/sandbox.py

@@ -1,5 +1,6 @@
 from dataclasses import dataclass
 from datetime import timedelta
+from uuid import uuid4
 
 from domain.sandbox import SandboxSession
 from usecase.interface import Clock, Logger, SandboxRuntime, SandboxSessionRepository
@@ -26,7 +27,47 @@ class CreateSandbox:
         self._ttl = ttl
 
     def execute(self, command: CreateSandboxCommand) -> SandboxSession:
-        raise NotImplementedError
+        now = self._clock.now()
+        session = self._repository.get_active_by_chat_id(command.chat_id)
+
+        if session is not None and session.expires_at > now:
+            self._logger.info(
+                'sandbox_reused',
+                attrs={
+                    'chat_id': command.chat_id,
+                    'session_id': session.session_id,
+                    'container_id': session.container_id,
+                },
+            )
+            return session
+
+        if session is not None:
+            self._logger.info(
+                'sandbox_replaced',
+                attrs={
+                    'chat_id': command.chat_id,
+                    'session_id': session.session_id,
+                    'container_id': session.container_id,
+                },
+            )
+            self._runtime.stop(session.container_id)
+            self._repository.delete(session.session_id)
+
+        new_session = self._runtime.create(
+            session_id=_new_session_id(),
+            chat_id=command.chat_id,
+            expires_at=now + self._ttl,
+        )
+        self._repository.save(new_session)
+        self._logger.info(
+            'sandbox_created',
+            attrs={
+                'chat_id': command.chat_id,
+                'session_id': new_session.session_id,
+                'container_id': new_session.container_id,
+            },
+        )
+        return new_session
 
 
 class CleanupExpiredSandboxes:
@@ -44,3 +85,7 @@ class CleanupExpiredSandboxes:
 
     def execute(self) -> list[SandboxSession]:
         raise NotImplementedError
+
+
+def _new_session_id() -> str:
+    return uuid4().hex