From 1e4744a7cba4f6be3f4d5d897268bf1f1bed2059 Mon Sep 17 00:00:00 2001
From: Cliff Hill <xlorep@darkhelm.org>
Date: Thu, 30 Sep 2021 12:25:40 -0400
Subject: [PATCH] Making settings a little neater.

Signed-off-by: Cliff Hill <xlorep@darkhelm.org>
---
 src/playlist/data/settings.py | 17 ++++++++++++-----
 src/playlist/plex/server.py   | 36 +++++++++++++++++++++++++++--------
 2 files changed, 40 insertions(+), 13 deletions(-)

diff --git a/src/playlist/data/settings.py b/src/playlist/data/settings.py
index a4b6963..0f15284 100644
--- a/src/playlist/data/settings.py
+++ b/src/playlist/data/settings.py
@@ -1,6 +1,8 @@
 """Define and control the Settings object for the playlist app."""
 from __future__ import annotations
 
+import collections.abc
+import contextlib
 import dataclasses
 import datetime
 import functools
@@ -12,7 +14,7 @@ import yaml
 from playlist.data import base
 from playlist.data import const
 
-__all__ = ["get", "write"]
+__all__ = ["get", "modify"]
 
 
 @dataclasses.dataclass
@@ -131,7 +133,12 @@ def get() -> Settings:  # pragma: no cover
     return instance
 
 
-def write() -> None:  # pragma: no cover
-    """Write the Settings object instance."""
-    filepath = const.PATHS.CONFIG / const.SETTINGS_FILENAME
-    get().yaml_write(filepath)
+@contextlib.contextmanager
+def modify() -> collections.abc.Generator[Settings, None, None]:  # pragma: no cover
+    """Provide the Settings object to make a modification and automatically save it."""
+    s = get()
+    try:
+        yield s
+    finally:
+        filepath = const.PATHS.CONFIG / const.SETTINGS_FILENAME
+        s.yaml_write(filepath)
diff --git a/src/playlist/plex/server.py b/src/playlist/plex/server.py
index 28f0c9d..d1295be 100644
--- a/src/playlist/plex/server.py
+++ b/src/playlist/plex/server.py
@@ -19,6 +19,32 @@ __all__ = ["gen_tracks", "total_track_count", "get_creds"]
 throttle = asyncio.BoundedSemaphore(const.MAX_PROCESSES)
 
 
+def calc_delay(times: list[float], weights: list[float]) -> None:
+    """Calculate the process delay.
+
+    This is based on a weighted harmonic mean of the times the processes took in
+    the last run.
+    """
+    with settings.modify() as s:
+        avg_time_per_batch = utils.harmonic_mean(times, weights=weights)
+        delay = avg_time_per_batch / const.MAX_PROCESSES
+        s.download.process_delay = round(delay, ndigits=6)
+
+
+def calc_duration(durations: list[int]) -> None:
+    """Calculate the average duration and max tracks to play each day.
+
+    This is based on the geometric mean of the durations of every track loaded from
+    Plex.  The maximum tracks to load for a day is based on the average duration calculated
+    and the amount of time that the system was played the previous day.
+    """
+    with settings.modify() as s:
+        avg_track_duration = statistics.geometric_mean(durations)
+        s.track.duration = round(avg_track_duration, ndigits=6)
+        playtime_seconds = settings.get().playlist.playtime.total_seconds()
+        s.playlist.max_tracks = int(playtime_seconds / avg_track_duration)
+
+
 async def gen_tracks(
     *,
     batch_size: int = settings.get().download.batch_size,
@@ -50,14 +76,8 @@ async def gen_tracks(
             durations.append(track.duration)
             yield track
 
-    avg_time_per_batch = utils.harmonic_mean(times, weights=weights)
-    avg_track_duration = statistics.geometric_mean(durations)
-    delay = avg_time_per_batch / const.MAX_PROCESSES
-    settings.get().download.process_delay = round(delay, ndigits=6)
-    settings.get().track.duration = round(avg_track_duration, ndigits=6)
-    playtime_seconds = settings.get().playlist.playtime.total_seconds()
-    settings.get().playlist.max_tracks = int(playtime_seconds / avg_track_duration)
-    settings.write()
+    calc_delay(times, weights)
+    calc_duration(durations)
 
 
 async def total_track_count() -> int: