Add campaign property for campaign start time.

This field is optional. Omitting the field (or using only a date instead
of a full timestamp) will use the old behavior of picking a random
daylight hour to start the campaign.

This doesn't include any UI in the new game wizard yet. This is only a
campaign yaml option.

https://github.com/dcs-liberation/dcs_liberation/issues/2400

game/campaignloader/campaign.py

@@ -1,12 +1,11 @@
 from __future__ import annotations
 
 import datetime
-import json
 import logging
 from collections.abc import Iterator
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Dict, Optional, Tuple
+from typing import Any, Dict, Tuple
 
 import yaml
 from packaging.version import Version
@@ -49,7 +48,8 @@ class Campaign:
 
     recommended_player_faction: str
     recommended_enemy_faction: str
-    recommended_start_date: Optional[datetime.date]
+    recommended_start_date: datetime.date | None
+    recommended_start_time: datetime.time | None
 
     recommended_player_money: int
     recommended_enemy_money: int
@@ -64,10 +64,7 @@ class Campaign:
     @classmethod
     def from_file(cls, path: Path) -> Campaign:
         with path.open() as campaign_file:
-            if path.suffix.lower() == ".yaml":
-                data = yaml.safe_load(campaign_file)
-            else:
-                data = json.load(campaign_file)
+            data = yaml.safe_load(campaign_file)
 
         sanitized_theater = data["theater"].replace(" ", "")
         version_field = data.get("version", "0")
@@ -80,14 +77,15 @@ class Campaign:
             version = Version(str(version_field))
 
         start_date_raw = data.get("recommended_start_date")
-
-        # YAML automatically parses dates, but while we still support JSON campaigns we
-        # need to be able to handle parsing dates from strings ourselves as well.
-        start_date: Optional[datetime.date]
-        if isinstance(start_date_raw, str):
-            start_date = datetime.date.fromisoformat(start_date_raw)
+        # YAML automatically parses dates.
+        start_date: datetime.date | None
+        start_time: datetime.time | None = None
+        if isinstance(start_date_raw, datetime.datetime):
+            start_date = start_date_raw.date()
+            start_time = start_date_raw.time()
         elif isinstance(start_date_raw, datetime.date):
             start_date = start_date_raw
+            start_time = None
         elif start_date_raw is None:
             start_date = None
         else:
@@ -104,6 +102,7 @@ class Campaign:
             data.get("recommended_player_faction", "USA 2005"),
             data.get("recommended_enemy_faction", "Russia 1990"),
             start_date,
+            start_time,
             data.get("recommended_player_money", DEFAULT_BUDGET),
             data.get("recommended_enemy_money", DEFAULT_BUDGET),
             data.get("recommended_player_income_multiplier", 1.0),