From c49f244ca2c2490c7f0e4caea21a07a6f7cb1455 Mon Sep 17 00:00:00 2001
From: Richard Frith-Macdonald <rfm@gnu.org>
Date: Sun, 19 Dec 2021 11:02:02 +0000
Subject: [PATCH] Allow lookup for a recent match of an alarm

---
 ChangeLog            |  7 +++++++
 EcAlarmDestination.h |  8 ++++++++
 EcAlarmDestination.m | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index cfe94e4..2480c45 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2021-12-19 Richard Frith-Macdonald <rfm@gnu.org>
+
+	* EcAlarmDestination.h:
+	* EcAlarmDestination.m:
+	Add (-latest:) method to find the most recent match for an alarm
+	in the queue/active/cleared data structures.
+
 2021-12-16 Richard Frith-Macdonald <rfm@gnu.org>
 
 	* EcCommand.m:
diff --git a/EcAlarmDestination.h b/EcAlarmDestination.h
index f4b4e3f..cd5224f 100644
--- a/EcAlarmDestination.h
+++ b/EcAlarmDestination.h
@@ -184,6 +184,14 @@
  */
 - (BOOL) isRunning;
 
+/** Finds and returns the most recent alarm in the system which matches
+ * (is equal to) toFind.  This searches the queue of alarms to be processed,
+ * the set of active alarms, and the set of cleared alarms (in that order)
+ * returning the first match found.  If no match is found the method
+ * returns nil.
+ */
+- (EcAlarm*) latest: (EcAlarm*)toFind;
+
 /** Returns an array containing the known managed objects.
  */
 - (NSArray*) managed;
diff --git a/EcAlarmDestination.m b/EcAlarmDestination.m
index b934835..9a3bc36 100644
--- a/EcAlarmDestination.m
+++ b/EcAlarmDestination.m
@@ -374,6 +374,39 @@
   return result;
 }
 
+- (EcAlarm*) latest: (EcAlarm*)toFind
+{
+  EcAlarm	*found = nil;
+  NSUInteger	index;
+
+  [_alarmLock lock];
+  /* First try to find the most recent match in the queue
+   */
+  index = [_alarmQueue count];
+  while (index-- > 0)
+    {
+      EcAlarm	*a = [_alarmQueue objectAtIndex: index];
+
+      if ([a isEqual: toFind])
+	{
+	  found = RETAIN(a);
+	  break;
+	}
+    }
+  if (nil == found)
+    {
+      /* Not in queue ... try active alarms or clears
+       */
+      found = RETAIN([_alarmsActive member: toFind]);
+      if (nil == found)
+	{
+	  found = RETAIN([_alarmsCleared member: toFind]);
+	}
+    }
+  [_alarmLock unlock];
+  return AUTORELEASE(found);  
+}
+
 - (NSArray*) managed
 {
   NSArray	*a;