37: Add re-armable CROSSING alarm trigger

README_alarm.md

@@ -140,7 +140,7 @@ Supported column values:
 - `ID`: integer alarm identifier. IDs should be unique. Action files use this ID to select alarms.
 - `ASSET`: `SOL`, `ETH`, or `BTC`.
 - `CONDITION`: a comparison or range expression. It must be one token with no whitespace.
-- `TRIGGER`: `ONETIME`, `PERSISTENT`, or `PERSISTENT:<seconds>`.
+- `TRIGGER`: `ONETIME`, `CROSSING`, `PERSISTENT`, or `PERSISTENT:<seconds>`.
 
 A trailing comment is allowed after a variable value or trigger.
 
@@ -210,7 +210,7 @@ At exactly `LIQ+1%`, only the first condition matches. The corresponding short-p
 
 ## Trigger behavior
 
-On the first accepted oracle price after startup or reconnect, an already-satisfied alarm can trigger immediately.
+On the first accepted oracle price after startup, an already-satisfied `ONETIME` or `PERSISTENT` alarm can trigger immediately. A `CROSSING` alarm only establishes its initial state.
 
 ### `ONETIME`
 
@@ -219,6 +219,23 @@ On the first accepted oracle price after startup or reconnect, an already-satisf
 - Leaving and re-entering the condition does not re-arm it.
 - Restarting the application re-arms it because alarm state is held only in memory.
 
+### `CROSSING`
+
+- Triggers when the condition changes from not satisfied to satisfied.
+- The first accepted price establishes the initial state and never triggers the alarm.
+- Remaining inside the condition does not trigger again.
+- Leaving the condition re-arms the alarm, so the next entry triggers again.
+- A grace period is not supported; `CROSSING:<seconds>` is rejected.
+
+The condition determines the crossing direction. For example:
+
+```text
+19  SOL  >={{SOL_LONG_ENTRY_PRICE}}  CROSSING
+20  SOL  <{{SOL_LONG_ENTRY_PRICE}}   CROSSING
+```
+
+Alarm 19 triggers when the price enters the profitable side from below. Alarm 20 triggers when it enters the losing side from above. With a range condition, `CROSSING` triggers whenever the price enters the range from either side.
+
 ### `PERSISTENT`
 
 - Triggers immediately on the first accepted matching price.

src/main/tjava/com/r35157/jupiterperpsalarm/impl/ref/AlarmConfigurationParser.tjava

@@ -94,6 +94,10 @@ public final class AlarmConfigurationParser {
             return new TriggerConfiguration(AlarmTrigger.ONETIME, 0);
         }
 
+        if (normalized.equals("CROSSING")) {
+            return new TriggerConfiguration(AlarmTrigger.CROSSING, 0);
+        }
+
         if (normalized.equals("PERSISTENT")) {
             return new TriggerConfiguration(AlarmTrigger.PERSISTENT, 0);
         }
@@ -128,6 +132,10 @@ public final class AlarmConfigurationParser {
             throw new IllegalArgumentException("ONETIME cannot have a grace period: " + triggerText);
         }
 
+        if (normalized.startsWith("CROSSING:")) {
+            throw new IllegalArgumentException("CROSSING cannot have a grace period: " + triggerText);
+        }
+
         throw new IllegalArgumentException("Unknown trigger: " + triggerText);
     }
 

src/main/tjava/com/r35157/jupiterperpsalarm/impl/ref/AlarmTrigger.tjava

@@ -2,5 +2,6 @@ package com.r35157.jupiterperpsalarm.impl.ref;
 
 public enum AlarmTrigger {
     ONETIME,
+    CROSSING,
     PERSISTENT
 }

src/main/tjava/com/r35157/jupiterperpsalarm/impl/ref/PriceAlarm.tjava

@@ -41,6 +41,10 @@ public final class PriceAlarm {
                 ? reached
                 : reached && !previousReached;
 
+        boolean crossedIntoTriggeredSide = previousReached != null
+                && reached
+                && !previousReached;
+
         previousReached = reached;
 
         if (!reached) {
@@ -57,6 +61,13 @@ public final class PriceAlarm {
             return;
         }
 
+        if (definition.trigger() == AlarmTrigger.CROSSING) {
+            if (crossedIntoTriggeredSide) {
+                trigger(price, condition);
+            }
+            return;
+        }
+
         if (definition.trigger() == AlarmTrigger.PERSISTENT) {
             if (lastTriggeredAt == null || persistentGracePeriodHasPassed()) {
                 trigger(price, condition);