simplify period deactivation logic, refactor advance_state logic into check_not_finished wrapper

bot/models.py

@@ -1,5 +1,6 @@
 import datetime
 import enum
+import functools
 
 from sqlalchemy import Boolean, Column, DateTime, Enum, ForeignKey, Integer, Text
 from sqlalchemy.ext.declarative import declarative_base
@@ -36,7 +37,7 @@ class Guild(Base):
     submission_channel = Column(Integer, nullable=True)  # The channel being scanned for messages by this particular guild.
 
     current_period = Column(Integer, ForeignKey('period.id'), nullable=True)  # The period currently active for this guild.
-    all_periods = relationship("Period", back_populates="guild")  # All periods ever started inside this guild
+    periods = relationship("Period", back_populates="guild")  # All periods ever started inside this guild
 
     active = Column(Boolean, default=True)  # Whether or not the bot is active inside the given Guild. Used for better querying.
     joined = Column(DateTime, default=datetime.datetime.utcnow)  # The initial join time for this bot to a particular Discord.
@@ -73,15 +74,24 @@ class Period(Base):
     voting_time = Column(DateTime, nullable=True)  # When this period switched to the Voting state.
     finished_time = Column(DateTime, nullable=True)  # When this period switched to the Finished state.
 
+    def check_not_finished(self, func):
+        """
+        Throws `FinishedPeriod` if the period has already completed, is inactive, or is in it's Finished State.
+        """
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            if self.state is PeriodStates.FINISHED: raise FinishedPeriod(f"Period is in it's Finished state.")
+            elif not self.active: raise FinishedPeriod("Period is no longer active.")
+            elif self.completed: raise FinishedPeriod("Period is already completed.")
+            func(*args, **kwargs)
+
+        return wrapper
+
+    @check_not_finished
     def advance_state(self) -> PeriodStates:
         """
         Advances the current recorded state of this Period, recording timestamps as needed.
-
-        Throws FinishedPeriod if the period has already completed.
         """
-        if self.state is PeriodStates.FINISHED: raise FinishedPeriod(f"Period is in it's Finished state.")
-        elif not self.active: raise FinishedPeriod("Period is no longer active.")
-
         next_state = PeriodStates(int(self.state) + 1)
         if self.state == PeriodStates.READY:
             self.submissions_time = datetime.datetime.utcnow()
@@ -95,3 +105,13 @@ class Period(Base):
             self.active = False
 
         return next_state
+
+    @check_not_finished
+    def deactivate(self) -> None:
+        """
+        Deactivates the period, setting it as inactive.
+
+        Use `advance_state` if you want to properly advance the state.
+        """
+        self.finished_time = datetime.datetime.utcnow()
+        self.active = False