From f1f09bd4cb3f0144421177a248c4bd3c5f1565b0 Mon Sep 17 00:00:00 2001
From: Jason Dove <jason@jasondove.me>
Date: Wed, 8 Sep 2021 22:12:47 -0500
Subject: [PATCH] fix sorting episodes without metadata (#353)

---
 CHANGELOG.md                                           | 2 ++
 ErsatzTV.Core/Scheduling/ChronologicalMediaComparer.cs | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9dcdd2451..c9b40900b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Properly order elements
   - Omit channels with no programmes
   - Properly identify channels using the format number.etv like `15.etv`
+- Fix sorting episodes without episode metadata
+  - This bug prevented playouts from building and was most often seen when grouping multi-part episodes, as shows are sorted chronologically before checking for multi-part episodes
 
 ## [0.0.55-alpha] - 2021-09-03
 ### Fixed
diff --git a/ErsatzTV.Core/Scheduling/ChronologicalMediaComparer.cs b/ErsatzTV.Core/Scheduling/ChronologicalMediaComparer.cs
index 22331d2e7..3c6add122 100644
--- a/ErsatzTV.Core/Scheduling/ChronologicalMediaComparer.cs
+++ b/ErsatzTV.Core/Scheduling/ChronologicalMediaComparer.cs
@@ -66,13 +66,17 @@ namespace ErsatzTV.Core.Scheduling
 
             int episode1 = x switch
             {
-                Episode e => e.EpisodeMetadata.Max(em => em.EpisodeNumber),
+                Episode e => e.EpisodeMetadata.HeadOrNone().Match(
+                    em => em.EpisodeNumber,
+                    () => int.MaxValue),
                 _ => int.MaxValue
             };
 
             int episode2 = y switch
             {
-                Episode e => e.EpisodeMetadata.Max(em => em.EpisodeNumber),
+                Episode e => e.EpisodeMetadata.HeadOrNone().Match(
+                    em => em.EpisodeNumber,
+                    () => int.MaxValue),
                 _ => int.MaxValue
             };