[jtx] Add RecurrenceFieldsBuilder (#388)

Author: cketti

lib/src/main/kotlin/at/bitfire/synctools/mapping/jtx/JtxItemBuilder.kt

@@ -11,6 +11,7 @@ import android.content.Entity
 import at.bitfire.synctools.icalendar.AssociatedComponents
 import at.bitfire.synctools.mapping.jtx.builder.CollectionIdBuilder
 import at.bitfire.synctools.mapping.jtx.builder.DescriptionBuilder
+import at.bitfire.synctools.mapping.jtx.builder.RecurrenceFieldsBuilder
 import at.bitfire.synctools.mapping.jtx.builder.JtxEntityBuilder
 import at.bitfire.synctools.mapping.jtx.builder.SyncPropertiesBuilder
 import at.bitfire.synctools.storage.jtx.JtxItemAndExceptions
@@ -33,7 +34,8 @@ class JtxItemBuilder(
         CollectionIdBuilder(collectionId),
         SyncPropertiesBuilder(fileName, eTag, scheduleTag, flags),
 
-        DescriptionBuilder()
+        DescriptionBuilder(),
+        RecurrenceFieldsBuilder()
     )
 
     fun build(component: AssociatedComponents<CalendarComponent>): JtxItemAndExceptions {

lib/src/main/kotlin/at/bitfire/synctools/mapping/jtx/builder/RecurrenceFieldsBuilder.kt

@@ -0,0 +1,136 @@
+/*
+ * This file is part of bitfireAT/synctools which is released under GPLv3.
+ * Copyright © All Contributors. See the LICENSE and AUTHOR files in the root directory for details.
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package at.bitfire.synctools.mapping.jtx.builder
+
+import android.content.Entity
+import at.bitfire.synctools.icalendar.DatePropertyTzMapper.normalizedDate
+import at.bitfire.synctools.icalendar.DatePropertyTzMapper.normalizedDates
+import at.bitfire.synctools.icalendar.recurrenceId
+import at.bitfire.synctools.util.AndroidTimeUtils.toTimestamp
+import at.techbee.jtx.JtxContract
+import net.fortuna.ical4j.model.Property
+import net.fortuna.ical4j.model.component.CalendarComponent
+import net.fortuna.ical4j.model.property.DateListProperty
+import net.fortuna.ical4j.model.property.RRule
+import java.time.Instant
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.ZoneOffset
+import java.time.ZonedDateTime
+import java.time.temporal.Temporal
+import java.util.logging.Logger
+
+class RecurrenceFieldsBuilder : JtxEntityBuilder {
+
+    private val logger
+        get() = Logger.getLogger(javaClass.name)
+
+    override fun build(from: CalendarComponent, main: CalendarComponent, to: Entity) {
+        if (from === main) {
+            buildMainItem(main, to)
+        } else {
+            buildExceptionItem(from, to)
+        }
+    }
+
+    private fun buildMainItem(main: CalendarComponent, to: Entity) {
+        to.entityValues.putNull(JtxContract.JtxICalObject.RECURID)
+        to.entityValues.putNull(JtxContract.JtxICalObject.RECURID_TIMEZONE)
+
+        buildRRule(main, to)
+        buildRDate(main, to)
+        buildExDate(main, to)
+    }
+
+    private fun buildRRule(main: CalendarComponent, to: Entity) {
+        val rRules = main.getProperties<RRule<*>>(Property.RRULE)
+        if (rRules.isEmpty()) {
+            to.entityValues.putNull(JtxContract.JtxICalObject.RRULE)
+            return
+        }
+
+        // Note: All but the last RRULE property are ignored.
+        val rrule = rRules.last().value
+        to.entityValues.put(JtxContract.JtxICalObject.RRULE, rrule)
+    }
+
+    private fun buildRDate(main: CalendarComponent, to: Entity) {
+        // Note: RDATE properties with a PERIOD value are currently not supported and ignored.
+        buildDateList(main, to, Property.RDATE, JtxContract.JtxICalObject.RDATE)
+    }
+
+    private fun buildExDate(main: CalendarComponent, to: Entity) {
+        buildDateList(main, to, Property.EXDATE, JtxContract.JtxICalObject.EXDATE)
+    }
+
+    private fun buildDateList(
+        main: CalendarComponent,
+        to: Entity,
+        propertyName: String,
+        columnName: String
+    ) {
+        val dateListProperties = main.getProperties<DateListProperty<*>>(propertyName)
+        if (dateListProperties.isEmpty()) {
+            to.entityValues.putNull(columnName)
+            return
+        }
+
+        val timestampListString = dateListProperties
+            .flatMap { it.normalizedDates() }
+            .map { it.toTimestamp() }
+            .joinToString(separator = ",")
+            .takeIf { it.isNotEmpty() }
+
+        if (timestampListString == null) {
+            to.entityValues.putNull(columnName)
+        } else {
+            to.entityValues.put(columnName, timestampListString)
+        }
+    }
+
+    private fun buildExceptionItem(exception: CalendarComponent, to: Entity) {
+        buildRecurrenceId(exception, to)
+
+        to.entityValues.putNull(JtxContract.JtxICalObject.RRULE)
+        to.entityValues.putNull(JtxContract.JtxICalObject.RDATE)
+        to.entityValues.putNull(JtxContract.JtxICalObject.EXDATE)
+    }
+
+    private fun buildRecurrenceId(exception: CalendarComponent, to: Entity) {
+        val recurrenceId = exception.recurrenceId
+        if (recurrenceId == null) {
+            to.entityValues.putNull(JtxContract.JtxICalObject.RECURID)
+            to.entityValues.putNull(JtxContract.JtxICalObject.RECURID_TIMEZONE)
+            return
+        }
+
+        to.entityValues.put(JtxContract.JtxICalObject.RECURID, recurrenceId.value)
+        val timeZoneId = recurrenceId.normalizedDate().getTimeZoneId()
+        to.entityValues.put(JtxContract.JtxICalObject.RECURID_TIMEZONE, timeZoneId)
+    }
+
+    private fun Temporal.getTimeZoneId(): String? = when (this) {
+        is ZonedDateTime -> {
+            this.zone.id
+        }
+        is Instant -> {
+            ZoneOffset.UTC.id
+        }
+        is LocalDateTime -> {
+            // Timezone unknown => floating time
+            null
+        }
+        is LocalDate -> {
+            // Without time, it is considered all-day
+            JtxContract.JtxICalObject.TZ_ALLDAY
+        }
+        else -> {
+            logger.warning("Ignoring unsupported temporal type: ${this::class}")
+            null
+        }
+    }
+}