Fix multi agent system

src/primaite/game/environment.py

@@ -1,7 +1,8 @@
-from typing import Any, Dict, Optional, SupportsFloat, Tuple
+from typing import Any, Dict, Final, Optional, SupportsFloat, Tuple
 
 import gymnasium
 from gymnasium.core import ActType, ObsType
+from ray.rllib.env.multi_agent_env import MultiAgentEnv
 
 from primaite.game.agent.interface import ProxyAgent
 from primaite.game.game import PrimaiteGame
@@ -86,3 +87,76 @@ class PrimaiteRayEnv(gymnasium.Env):
     def step(self, action: ActType) -> Tuple[ObsType, SupportsFloat, bool, bool, Dict]:
         """Perform a step in the environment."""
         return self.env.step(action)
+
+
+class PrimaiteRayMARLEnv(MultiAgentEnv):
+    """Ray Environment that inherits from MultiAgentEnv to allow training MARL systems."""
+
+    def __init__(self, env_config: Optional[Dict] = None) -> None:
+        """Initialise the environment.
+
+        :param env_config: A dictionary containing the environment configuration. It must contain a single key, `game`
+            which is the PrimaiteGame instance.
+        :type env_config: Dict[str, PrimaiteGame]
+        """
+        self.game: PrimaiteGame = env_config["game"]
+        """Reference to the primaite game"""
+        self.agents: Final[Dict[str, ProxyAgent]] = {agent.agent_name: agent for agent in self.game.rl_agents}
+        """List of all possible agents in the environment. This list should not change!"""
+        self._agent_ids = list(self.agents.keys())
+
+        self.terminateds = set()
+        self.truncateds = set()
+        self.observation_space = gymnasium.spaces.Dict(
+            {name: agent.observation_manager.space for name, agent in self.agents.items()}
+        )
+        self.action_space = gymnasium.spaces.Dict(
+            {name: agent.action_manager.space for name, agent in self.agents.items()}
+        )
+        super().__init__()
+
+    def reset(self, *, seed: int = None, options: dict = None) -> Tuple[ObsType, Dict]:
+        """Reset the environment."""
+        self.game.reset()
+        state = self.game.get_sim_state()
+        self.game.update_agents(state)
+        next_obs = self._get_obs()
+        info = {}
+        return next_obs, info
+
+    def step(
+        self, actions: Dict[str, ActType]
+    ) -> Tuple[Dict[str, ObsType], Dict[str, SupportsFloat], Dict[str, bool], Dict[str, bool], Dict]:
+        """Perform a step in the environment. Adherent to Ray MultiAgentEnv step API.
+
+        :param actions: Dict of actions. The key is agent identifier and the value is a gymnasium action instance.
+        :type actions: Dict[str, ActType]
+        :return: Observations, rewards, terminateds, truncateds, and info. Each one is a dictionary keyed by agent
+            identifier.
+        :rtype: Tuple[Dict[str,ObsType], Dict[str, SupportsFloat], Dict[str,bool], Dict[str,bool], Dict]
+        """
+        # 1. Perform actions
+        for agent_name, action in actions.items():
+            self.agents[agent_name].store_action(action)
+        self.game.apply_agent_actions()
+
+        # 2. Advance timestep
+        self.game.advance_timestep()
+
+        # 3. Get next observations
+        state = self.game.get_sim_state()
+        self.game.update_agents(state)
+        next_obs = self._get_obs()
+
+        # 4. Get rewards
+        rewards = {name: agent.reward_function.current_reward for name, agent in self.agents.items()}
+        terminateds = {name: False for name, _ in self.agents.items()}
+        truncateds = {name: self.game.calculate_truncated() for name, _ in self.agents.items()}
+        infos = {}
+        terminateds["__all__"] = len(self.terminateds) == len(self.agents)
+        truncateds["__all__"] = self.game.calculate_truncated()
+        return next_obs, rewards, terminateds, truncateds, infos
+
+    def _get_obs(self) -> Dict[str, ObsType]:
+        """Return the current observation."""
+        return {name: agent.observation_manager.current_observation for name, agent in self.agents.items()}