allow string values for count instruction in sequential schedules (#2741)

* allow string values for count instruction in sequential schedules

* fix potential div by zero

CHANGELOG.md

@@ -62,6 +62,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix high CPU when errors are displayed; errors will now work ahead before throttling to realtime, similar to primary content
 - Fix startup error caused by duplicate smart collection names (and no longer allow duplicate smart collection names)
 - Fix erroneous downgrade health check failure with some installations that use MariaDB
+- Sequential schedules: fix `count` instruction validation to accept integer (constant) or string (expression)
 
 ### Changed
 - No longer round framerate to nearest integer when normalizing framerate

ErsatzTV.Core/Scheduling/YamlScheduling/Handlers/YamlPlayoutCountHandler.cs

@@ -43,7 +43,7 @@ public class YamlPlayoutCountHandler(EnumeratorCache enumeratorCache) : YamlPlay
                 e.Result = name switch
                 {
                     "count" => enumeratorCount,
-                    "random" => random.Next() % enumeratorCount,
+                    "random" => enumeratorCount > 0 ? random.Next() % enumeratorCount : 0,
                     _ => e.Result
                 };
             };

ErsatzTV/Resources/sequential-schedule-import.schema.json

@@ -191,7 +191,7 @@
       "countInstruction": {
         "type": "object",
         "properties": {
-          "count": { "type": "integer" },
+          "count": { "type": ["integer", "string"] },
           "content": { "type": "string" },
           "custom_title": { "type": "string" },
           "filler_kind": { "$ref": "#/$defs/enums/filler_kind" },

ErsatzTV/Resources/sequential-schedule.schema.json

@@ -242,7 +242,7 @@
       "countInstruction": {
         "type": "object",
         "properties": {
-          "count": { "type": "integer" },
+          "count": { "type": ["integer", "string"] },
           "content": { "type": "string" },
           "custom_title": { "type": "string" },
           "filler_kind": { "$ref": "#/$defs/enums/filler_kind" },