Add play/pause features to the sim.

There's no UI feedback for this yet other than the log messages.

https://github.com/dcs-liberation/dcs_liberation/issues/1704

game/sim/gameloop.py

@@ -0,0 +1,73 @@
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+from typing import Callable, TYPE_CHECKING
+
+from .gamelooptimer import GameLoopTimer
+from .missionsimulation import MissionSimulation, SimulationAlreadyCompletedError
+from .simspeedsetting import SimSpeedSetting
+
+if TYPE_CHECKING:
+    from game import Game
+    from game.debriefing import Debriefing
+
+
+class GameLoop:
+    def __init__(self, game: Game, on_complete: Callable[[], None]) -> None:
+        self.game = game
+        self.on_complete = on_complete
+        self.timer = GameLoopTimer(self.tick)
+        self.sim = MissionSimulation(self.game)
+        self.started = False
+        self.completed = False
+
+    def start(self) -> None:
+        if self.started:
+            raise RuntimeError("Cannot start game loop because it has already started")
+        self.started = True
+        self.sim.begin_simulation()
+
+    def pause(self) -> None:
+        self.set_simulation_speed(SimSpeedSetting.PAUSED)
+
+    def set_simulation_speed(self, simulation_speed: SimSpeedSetting) -> None:
+        self.timer.stop()
+        if simulation_speed != self.timer.simulation_speed:
+            logging.info(f"Speed changed to {simulation_speed}")
+        if not self.started:
+            self.start()
+        self.timer.set_speed(simulation_speed)
+
+    def run_to_first_contact(self) -> None:
+        self.pause()
+        logging.info("Running sim to first contact")
+        while not self.completed:
+            self.tick()
+
+    def pause_and_generate_miz(self, output: Path) -> None:
+        self.pause()
+        self.sim.generate_miz(output)
+
+    def pause_and_debrief(self, state_path: Path, force_end: bool) -> Debriefing:
+        self.pause()
+        return self.sim.debrief_current_state(state_path, force_end)
+
+    def complete_with_results(self, debriefing: Debriefing) -> None:
+        self.pause()
+        self.sim.process_results(debriefing)
+        self.completed = True
+
+    def tick(self) -> None:
+        if not self.started:
+            raise RuntimeError("Attempted to tick game loop before initialization")
+        try:
+            self.completed = self.sim.tick()
+            if self.completed:
+                self.pause()
+                logging.info(f"Simulation completed at {self.sim.time}")
+                self.on_complete()
+            else:
+                logging.info(f"Simulation continued at {self.sim.time}")
+        except SimulationAlreadyCompletedError:
+            logging.exception("Attempted to tick already completed sim")