From a9cb7b0e893cabee8213858beada1ba82e15c555 Mon Sep 17 00:00:00 2001
From: Alex Baker <alex@tasks.org>
Date: Sun, 17 Sep 2023 12:48:50 -0500
Subject: [PATCH] Fix default reminders for remote icalendar tasks

---
 .../main/java/org/tasks/caldav/iCalendar.kt   | 12 +++++---
 .../java/org/tasks/caldav/iCalendarTest.kt    | 29 +++++++++++++++++++
 2 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 app/src/test/java/org/tasks/caldav/iCalendarTest.kt

diff --git a/app/src/main/java/org/tasks/caldav/iCalendar.kt b/app/src/main/java/org/tasks/caldav/iCalendar.kt
index 970420a13..cfde1c3f4 100644
--- a/app/src/main/java/org/tasks/caldav/iCalendar.kt
+++ b/app/src/main/java/org/tasks/caldav/iCalendar.kt
@@ -24,7 +24,6 @@ import net.fortuna.ical4j.model.property.DateProperty
 import net.fortuna.ical4j.model.property.DtStart
 import net.fortuna.ical4j.model.property.Due
 import net.fortuna.ical4j.model.property.Geo
-import net.fortuna.ical4j.model.property.ProdId
 import net.fortuna.ical4j.model.property.RelatedTo
 import net.fortuna.ical4j.model.property.Status
 import net.fortuna.ical4j.model.property.XProperty
@@ -65,6 +64,7 @@ import java.io.ByteArrayOutputStream
 import java.io.StringReader
 import java.text.ParseException
 import java.util.TimeZone
+import java.util.regex.Pattern
 import javax.inject.Inject
 import kotlin.math.max
 import kotlin.math.min
@@ -239,7 +239,7 @@ class iCalendar @Inject constructor(
             isNew &&
             remote.reminders.isEmpty() &&
             !calendar.ctag.isNullOrBlank() && // not initial sync
-            !remote.prodId().supportsReminders() // other client doesn't support reminder sync
+            vtodo?.prodId()?.supportsReminders() != true // other client doesn't support reminder sync
         ) {
             task.setDefaultReminders(preferences)
             alarmService.synchronizeAlarms(task.id, task.getDefaultAlarms().toMutableSet())
@@ -284,6 +284,7 @@ class iCalendar @Inject constructor(
         private const val MOZ_SNOOZE_TIME = "X-MOZ-SNOOZE-TIME"
         private const val MOZ_LASTACK = "X-MOZ-LASTACK"
         private const val HIDE_SUBTASKS = "1"
+        private val PRODID_MATCHER = ".*?PRODID:(.*?)\n.*".toPattern(Pattern.DOTALL)
         // VALARM extensions: https://datatracker.ietf.org/doc/html/rfc9074
         private val IGNORE_ALARM = DateTime("19760401T005545Z")
         private val IS_PARENT = { r: RelatedTo ->
@@ -326,8 +327,11 @@ class iCalendar @Inject constructor(
             }
 
         // this isn't necessarily the task originator but its the best we can do
-        fun ProdId.supportsReminders(): Boolean =
-            CLIENTS_WITH_REMINDER_SYNC.any { value.contains(it) }
+        fun String.supportsReminders(): Boolean =
+            CLIENTS_WITH_REMINDER_SYNC.any { contains(it) }
+
+        fun String.prodId(): String? =
+            PRODID_MATCHER.matcher(this).takeIf { it.matches() }?.group(1)
 
         private val CLIENTS_WITH_REMINDER_SYNC = listOf(
             "tasks.org",
diff --git a/app/src/test/java/org/tasks/caldav/iCalendarTest.kt b/app/src/test/java/org/tasks/caldav/iCalendarTest.kt
new file mode 100644
index 000000000..653d3544e
--- /dev/null
+++ b/app/src/test/java/org/tasks/caldav/iCalendarTest.kt
@@ -0,0 +1,29 @@
+package org.tasks.caldav
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.tasks.TestUtilities
+import org.tasks.caldav.iCalendar.Companion.prodId
+import org.tasks.caldav.iCalendar.Companion.supportsReminders
+
+class iCalendarTest {
+    @Test
+    fun parseProdId() {
+        assertEquals(
+            "-//Mozilla.org/NONSGML Mozilla Calendar V1.1//EN",
+            TestUtilities.readFile("thunderbird/basic_due_date.txt").prodId()
+        )
+    }
+
+    @Test
+    fun thunderbirdSupportsReminderSync() {
+        assertTrue(TestUtilities.readFile("thunderbird/basic_due_date.txt").supportsReminders())
+    }
+
+    @Test
+    fun nextcloudDoesNotSupportReminderSync() {
+        assertFalse(TestUtilities.readFile("nextcloud/basic_due_date.txt").supportsReminders())
+    }
+}
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