Finish moving gen into game.

game/runways.py

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+"""Runway information and selection."""
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from typing import Iterator, Optional, TYPE_CHECKING
+
+from dcs.terrain.terrain import Airport
+
+from game.airfields import AirfieldData
+from game.radio.radios import RadioFrequency
+from game.radio.tacan import TacanChannel
+from game.utils import Heading
+from game.weather import Conditions
+
+if TYPE_CHECKING:
+    from game.theater import ConflictTheater
+
+
+@dataclass(frozen=True)
+class RunwayData:
+    airfield_name: str
+    runway_heading: Heading
+    runway_name: str
+    atc: Optional[RadioFrequency] = None
+    tacan: Optional[TacanChannel] = None
+    tacan_callsign: Optional[str] = None
+    ils: Optional[RadioFrequency] = None
+    icls: Optional[int] = None
+
+    @classmethod
+    def for_airfield(
+        cls,
+        theater: ConflictTheater,
+        airport: Airport,
+        runway_heading: Heading,
+        runway_name: str,
+    ) -> RunwayData:
+        """Creates RunwayData for the given runway of an airfield.
+
+        Args:
+            theater: The theater the airport is in.
+            airport: The airfield the runway belongs to.
+            runway_heading: Heading of the runway.
+            runway_name: Identifier of the runway to use. e.g. "03" or "20L".
+        """
+        atc: Optional[RadioFrequency] = None
+        tacan: Optional[TacanChannel] = None
+        tacan_callsign: Optional[str] = None
+        ils: Optional[RadioFrequency] = None
+        try:
+            airfield = AirfieldData.for_airport(theater, airport)
+            if airfield.atc is not None:
+                atc = airfield.atc.uhf
+            else:
+                atc = None
+            tacan = airfield.tacan
+            tacan_callsign = airfield.tacan_callsign
+            ils = airfield.ils_freq(runway_name)
+        except KeyError:
+            logging.warning(f"No airfield data for {airport.name} ({airport.id}")
+        return cls(
+            airfield_name=airport.name,
+            runway_heading=runway_heading,
+            runway_name=runway_name,
+            atc=atc,
+            tacan=tacan,
+            tacan_callsign=tacan_callsign,
+            ils=ils,
+        )
+
+    @classmethod
+    def for_pydcs_airport(
+        cls, theater: ConflictTheater, airport: Airport
+    ) -> Iterator[RunwayData]:
+        for runway in airport.runways:
+            runway_number = runway.heading // 10
+            runway_side = ["", "L", "R"][runway.leftright]
+            runway_name = f"{runway_number:02}{runway_side}"
+            yield cls.for_airfield(
+                theater, airport, Heading.from_degrees(runway.heading), runway_name
+            )
+
+            # pydcs only exposes one runway per physical runway, so to expose
+            # both sides of the runway we need to generate the other.
+            heading = Heading.from_degrees(runway.heading).opposite
+            runway_number = heading.degrees // 10
+            runway_side = ["", "R", "L"][runway.leftright]
+            runway_name = f"{runway_number:02}{runway_side}"
+            yield cls.for_airfield(theater, airport, heading, runway_name)
+
+
+class RunwayAssigner:
+    def __init__(self, conditions: Conditions):
+        self.conditions = conditions
+
+    def angle_off_headwind(self, runway: RunwayData) -> Heading:
+        wind = Heading.from_degrees(self.conditions.weather.wind.at_0m.direction)
+        ideal_heading = wind.opposite
+        return runway.runway_heading.angle_between(ideal_heading)
+
+    def get_preferred_runway(
+        self, theater: ConflictTheater, airport: Airport
+    ) -> RunwayData:
+        """Returns the preferred runway for the given airport.
+
+        Right now we're only selecting runways based on whether or not
+        they have
+        ILS, but we could also choose based on wind conditions, or which
+        direction flight plans should follow.
+        """
+        runways = list(RunwayData.for_pydcs_airport(theater, airport))
+
+        # Find the runway with the best headwind first.
+        best_runways = [runways[0]]
+        best_angle_off_headwind = self.angle_off_headwind(best_runways[0])
+        for runway in runways[1:]:
+            angle_off_headwind = self.angle_off_headwind(runway)
+            if angle_off_headwind == best_angle_off_headwind:
+                best_runways.append(runway)
+            elif angle_off_headwind < best_angle_off_headwind:
+                best_runways = [runway]
+                best_angle_off_headwind = angle_off_headwind
+
+        for runway in best_runways:
+            # But if there are multiple runways with the same heading,
+            # prefer
+            # and ILS capable runway.
+            if runway.ils is not None:
+                return runway
+
+        # Otherwise the only difference between the two is the distance from
+        # parking, which we don't know, so just pick the first one.
+        return best_runways[0]