1 files changed, 88 insertions, 0 deletions
diff --git a/kennel/engine/systems/network.py b/kennel/engine/systems/network.py
new file mode 100644
index 0000000..7df8088
--- /dev/null
+++ b/kennel/engine/systems/network.py
@@ -0,0 +1,88 @@
+from enum import Enum
+from kennel.engine.entities.entity import EntityManager
+from .system import System, SystemType
+from abc import abstractmethod
+import asyncio
+
+
+class EventType(str, Enum):
+    ENTITY_BORN = "ENTITY_BORN"
+    ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE"
+    ENTITY_DEATH = "ENTITY_DEATH"
+
+
+class Event:
+    def __init__(self, event_type: EventType, data: dict):
+        self.event_type = event_type
+        self.data = data
+
+    def __str__(self):
+        return f"Event({self.event_type}, {self.data})"
+
+    def dict(self):
+        return {"event_type": self.event_type, "data": self.data}
+
+    @staticmethod
+    def from_dict(data: dict):
+        return Event(EventType(data["event_type"]), data["data"])
+
+
+class Publishable:
+    @abstractmethod
+    async def publish(self, event: Event):
+        pass
+
+
+class ClientEventTransformer:
+    @abstractmethod
+    def apply(self, event: Event) -> Event:
+        pass
+
+
+class EventProcessor:
+    @abstractmethod
+    def accept(self, entity_manager: EntityManager, event: Event) -> None:
+        pass
+
+
+class NetworkSystem(System):
+    def __init__(
+        self,
+        event_processor: EventProcessor,
+        client_event_transformer: ClientEventTransformer,
+    ):
+        super().__init__(SystemType.NETWORK)
+        self.event_processor = event_processor
+        self.client_event_transformer = client_event_transformer
+
+        self.events = []
+        self.clients = {}
+
+    async def update(self, entity_manager: EntityManager, delta_time: float) -> None:
+        for event in self.events:
+            self.event_processor.accept(entity_manager, event)
+        client_events = [
+            self.client_event_transformer.apply(entity_manager, event)
+            for event in self.events
+        ]
+        await asyncio.gather(
+            *[
+                client.publish(event)
+                for client in self.clients.values()
+                for event in client_events
+            ]
+        )
+        self.events = []
+
+    def client_event(self, client_id: str, event: Event) -> None:
+        event.data["client_id"] = client_id
+        self.events.append(event)
+
+    def add_event(self, event: Event) -> None:
+        self.events.append(event)
+
+    def add_client(self, client_id: str, client: Publishable) -> None:
+        self.clients[client_id] = client
+
+    def remove_client(self, client_id: str) -> None:
+        del self.clients[client_id]