refactor: Use Date type for scheduled post date / times (#1032)

Previous code accepted the `scheduledAt` value as a String, and kept it
as a String (including when serialising as part of a draft). Then it was
converted to an actual Date for display.

Refactor to keep it as a Date for as long as possible. Moshi decodes
Dates correctly over the network, and the database is configured to
serialise Dates as Longs.

This necessitates two migration steps to preserve any existing
`scheduledAt` values for drafts. The first step adds a new column to
store the date as a Long and copies over existing data. The second step
replaces the old column with the new column.

app/src/main/java/app/pachli/components/compose/ComposeActivity.kt

@@ -121,6 +121,7 @@ import com.mikepenz.iconics.utils.sizeDp
 import dagger.hilt.android.AndroidEntryPoint
 import java.io.File
 import java.io.IOException
+import java.util.Date
 import java.util.Locale
 import javax.inject.Inject
 import kotlin.math.max
@@ -292,8 +293,8 @@ class ComposeActivity :
             binding.composeEditField.setText(statusContent)
         }
 
-        if (!composeOptions?.scheduledAt.isNullOrEmpty()) {
+        composeOptions?.scheduledAt?.let {
-            binding.composeScheduleView.setDateTime(composeOptions?.scheduledAt)
+            binding.composeScheduleView.setDateTime(it)
         }
 
         setupLanguageSpinner(getInitialLanguages(composeOptions?.language, activeAccount))
@@ -314,7 +315,7 @@ class ComposeActivity :
                 viewModel.showContentWarningChanged(this)
             }
 
-            it.getString(KEY_SCHEDULED_TIME)?.let { time ->
+            (it.getSerializable(KEY_SCHEDULED_TIME) as? Date)?.let { time ->
                 viewModel.updateScheduledAt(time)
             }
         }
@@ -717,7 +718,7 @@ class ComposeActivity :
         outState.putParcelable(KEY_PHOTO_UPLOAD_URI, photoUploadUri)
         outState.putSerializable(KEY_VISIBILITY, viewModel.statusVisibility.value)
         outState.putBoolean(KEY_CONTENT_WARNING_VISIBLE, viewModel.showContentWarning.value)
-        outState.putString(KEY_SCHEDULED_TIME, viewModel.scheduledAt.value)
+        outState.putSerializable(KEY_SCHEDULED_TIME, viewModel.scheduledAt.value)
         super.onSaveInstanceState(outState)
     }
 
@@ -783,7 +784,7 @@ class ComposeActivity :
             // Can't reschedule a published status
             enableButton(binding.composeScheduleButton, clickable = false, colorActive = false)
         } else {
-            val attr = if (binding.composeScheduleView.time == null) {
+            val attr = if (viewModel.scheduledAt.value == null) {
                 android.R.attr.colorControlNormal
             } else {
                 android.R.attr.colorPrimary
@@ -970,7 +971,7 @@ class ComposeActivity :
     }
 
     private fun verifyScheduledTime(): Boolean {
-        return binding.composeScheduleView.verifyScheduledTime(binding.composeScheduleView.getDateTime(viewModel.scheduledAt.value))
+        return binding.composeScheduleView.verifyScheduledTime(viewModel.scheduledAt.value)
     }
 
     private fun onSendClicked() = lifecycleScope.launch {
@@ -1410,7 +1411,7 @@ class ComposeActivity :
         }
     }
 
-    override fun onTimeSet(time: String?) {
+    override fun onTimeSet(time: Date?) {
         viewModel.updateScheduledAt(time)
         if (verifyScheduledTime()) {
             scheduleBehavior.state = BottomSheetBehavior.STATE_HIDDEN

app/src/main/java/app/pachli/components/compose/ComposeViewModel.kt

@@ -58,6 +58,7 @@ import com.github.michaelbull.result.mapBoth
 import com.github.michaelbull.result.mapError
 import dagger.hilt.android.lifecycle.HiltViewModel
 import io.github.z4kn4fein.semver.constraints.toConstraint
+import java.util.Date
 import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.channels.BufferOverflow
@@ -138,7 +139,7 @@ class ComposeViewModel @Inject constructor(
     val showContentWarning = _showContentWarning.asStateFlow()
     private val _poll: MutableStateFlow<NewPoll?> = MutableStateFlow(null)
     val poll = _poll.asStateFlow()
-    private val _scheduledAt: MutableStateFlow<String?> = MutableStateFlow(null)
+    private val _scheduledAt: MutableStateFlow<Date?> = MutableStateFlow(null)
     val scheduledAt = _scheduledAt.asStateFlow()
 
     private val _media: MutableStateFlow<List<QueuedMedia>> = MutableStateFlow(emptyList())
@@ -637,7 +638,7 @@ class ComposeViewModel @Inject constructor(
         setupComplete = true
     }
 
-    fun updateScheduledAt(newScheduledAt: String?) {
+    fun updateScheduledAt(newScheduledAt: Date?) {
         if (newScheduledAt != scheduledAt.value) {
             scheduledTimeChanged = true
         }

app/src/main/java/app/pachli/components/compose/view/ComposeScheduleView.kt

@@ -33,11 +33,9 @@ import com.google.android.material.datepicker.DateValidatorPointForward
 import com.google.android.material.datepicker.MaterialDatePicker
 import com.google.android.material.timepicker.MaterialTimePicker
 import com.google.android.material.timepicker.TimeFormat
-import java.text.ParseException
 import java.text.SimpleDateFormat
 import java.util.Calendar
 import java.util.Date
-import java.util.Locale
 import java.util.TimeZone
 
 class ComposeScheduleView
@@ -47,7 +45,7 @@ class ComposeScheduleView
     defStyleAttr: Int = 0,
 ) : ConstraintLayout(context, attrs, defStyleAttr) {
     interface OnTimeSetListener {
-        fun onTimeSet(time: String?)
+        fun onTimeSet(time: Date?)
     }
 
     private var binding = ViewComposeScheduleBinding.inflate(
@@ -57,12 +55,6 @@ class ComposeScheduleView
     private var listener: OnTimeSetListener? = null
     private var dateFormat = SimpleDateFormat.getDateInstance()
     private var timeFormat = SimpleDateFormat.getTimeInstance()
-    private var iso8601 = SimpleDateFormat(
-        "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
-        Locale.getDefault(),
-    ).apply {
-        timeZone = TimeZone.getTimeZone("UTC")
-    }
 
     /** The date/time the user has chosen to schedule the status, in UTC */
     private var scheduleDateTimeUtc: Calendar? = null
@@ -190,20 +182,9 @@ class ComposeScheduleView
         picker.show((context as AppCompatActivity).supportFragmentManager, "time_picker")
     }
 
-    fun getDateTime(scheduledAt: String?): Date? {
+    fun setDateTime(scheduledAt: Date) {
-        scheduledAt?.let {
-            try {
-                return iso8601.parse(it)
-            } catch (_: ParseException) {
-            }
-        }
-        return null
-    }
-
-    fun setDateTime(scheduledAt: String?) {
-        val date = getDateTime(scheduledAt) ?: return
         initializeSuggestedTime()
-        scheduleDateTimeUtc!!.time = date
+        scheduleDateTimeUtc!!.time = scheduledAt
         updateScheduleUi()
     }
 
@@ -238,12 +219,9 @@ class ComposeScheduleView
         scheduleDateTimeUtc?.set(Calendar.HOUR_OF_DAY, hourOfDay)
         scheduleDateTimeUtc?.set(Calendar.MINUTE, minute)
         updateScheduleUi()
-        listener?.onTimeSet(time)
+        listener?.onTimeSet(scheduleDateTimeUtc?.time)
     }
 
-    val time: String?
-        get() = scheduleDateTimeUtc?.time?.let { iso8601.format(it) }
-
     private fun initializeSuggestedTime() {
         if (scheduleDateTimeUtc == null) {
             scheduleDateTimeUtc = calendar().apply {

app/src/main/java/app/pachli/components/drafts/DraftHelper.kt

@@ -63,7 +63,7 @@ class DraftHelper @Inject constructor(
         poll: NewPoll?,
         failedToSend: Boolean,
         failedToSendAlert: Boolean,
-        scheduledAt: String?,
+        scheduledAt: Date?,
         language: String?,
         statusId: String?,
     ) = withContext(Dispatchers.IO) {

app/src/main/java/app/pachli/service/SendStatusService.kt

@@ -40,6 +40,7 @@ import at.connyduck.calladapter.networkresult.fold
 import com.github.michaelbull.result.getOrElse
 import dagger.hilt.android.AndroidEntryPoint
 import java.io.IOException
+import java.util.Date
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.TimeUnit
 import javax.inject.Inject
@@ -247,30 +248,33 @@ class SendStatusService : Service() {
                 )
             }
 
-            sendResult.fold({ sentStatus ->
+            sendResult.fold(
-                statusesToSend.remove(statusId)
+                { sentStatus ->
-                // If the status was loaded from a draft, delete the draft and associated media files.
+                    statusesToSend.remove(statusId)
-                if (statusToSend.draftId != 0) {
+                    // If the status was loaded from a draft, delete the draft and associated media files.
-                    draftHelper.deleteDraftAndAttachments(statusToSend.draftId)
+                    if (statusToSend.draftId != 0) {
-                }
+                        draftHelper.deleteDraftAndAttachments(statusToSend.draftId)
+                    }
 
-                mediaUploader.cancelUploadScope(*statusToSend.media.map { it.localId }.toIntArray())
+                    mediaUploader.cancelUploadScope(*statusToSend.media.map { it.localId }.toIntArray())
 
-                val scheduled = !statusToSend.scheduledAt.isNullOrEmpty()
+                    val scheduled = statusToSend.scheduledAt != null
 
-                if (scheduled) {
+                    if (scheduled) {
-                    eventHub.dispatch(StatusScheduledEvent)
+                        eventHub.dispatch(StatusScheduledEvent)
-                } else if (!isNew) {
+                    } else if (!isNew) {
-                    eventHub.dispatch(StatusEditedEvent(statusToSend.statusId!!, sentStatus as Status))
+                        eventHub.dispatch(StatusEditedEvent(statusToSend.statusId!!, sentStatus as Status))
-                } else {
+                    } else {
-                    eventHub.dispatch(StatusComposedEvent(sentStatus as Status))
+                        eventHub.dispatch(StatusComposedEvent(sentStatus as Status))
-                }
+                    }
 
-                notificationManager.cancel(statusId)
+                    notificationManager.cancel(statusId)
-            }, { throwable ->
+                },
-                Timber.w(throwable, "failed sending status")
+                { throwable ->
-                failOrRetry(throwable, statusId)
+                    Timber.w(throwable, "failed sending status")
-            })
+                    failOrRetry(throwable, statusId)
+                },
+            )
             stopSelfWhenDone()
         }
     }
@@ -475,7 +479,7 @@ data class StatusToSend(
     val visibility: String,
     val sensitive: Boolean,
     val media: List<MediaToSend>,
-    val scheduledAt: String?,
+    val scheduledAt: Date?,
     val inReplyToId: String?,
     val poll: NewPoll?,
     val replyingStatusContent: String?,

core/database/src/main/kotlin/app/pachli/core/database/AppDatabase.kt

@@ -17,11 +17,17 @@
 
 package app.pachli.core.database
 
+import android.annotation.SuppressLint
+import android.content.ContentValues
+import android.database.sqlite.SQLiteDatabase.CONFLICT_ABORT
+import androidx.core.database.getStringOrNull
 import androidx.room.AutoMigration
 import androidx.room.Database
 import androidx.room.DeleteColumn
+import androidx.room.RenameColumn
 import androidx.room.RoomDatabase
 import androidx.room.migration.AutoMigrationSpec
+import androidx.sqlite.db.SupportSQLiteDatabase
 import app.pachli.core.database.dao.AccountDao
 import app.pachli.core.database.dao.ConversationsDao
 import app.pachli.core.database.dao.DraftDao
@@ -40,6 +46,9 @@ import app.pachli.core.database.model.StatusViewDataEntity
 import app.pachli.core.database.model.TimelineAccountEntity
 import app.pachli.core.database.model.TimelineStatusEntity
 import app.pachli.core.database.model.TranslatedStatusEntity
+import java.text.SimpleDateFormat
+import java.util.Locale
+import java.util.TimeZone
 
 @Suppress("ClassName")
 @Database(
@@ -55,13 +64,15 @@ import app.pachli.core.database.model.TranslatedStatusEntity
         TranslatedStatusEntity::class,
         LogEntryEntity::class,
     ],
-    version = 6,
+    version = 8,
     autoMigrations = [
         AutoMigration(from = 1, to = 2, spec = AppDatabase.MIGRATE_1_2::class),
         AutoMigration(from = 2, to = 3),
         AutoMigration(from = 3, to = 4),
         AutoMigration(from = 4, to = 5),
         AutoMigration(from = 5, to = 6),
+        AutoMigration(from = 6, to = 7, spec = AppDatabase.MIGRATE_6_7::class),
+        AutoMigration(from = 7, to = 8, spec = AppDatabase.MIGRATE_7_8::class),
     ],
 )
 abstract class AppDatabase : RoomDatabase() {
@@ -78,4 +89,54 @@ abstract class AppDatabase : RoomDatabase() {
     @DeleteColumn("TimelineStatusEntity", "contentCollapsed")
     @DeleteColumn("TimelineStatusEntity", "contentShowing")
     class MIGRATE_1_2 : AutoMigrationSpec
+
+    /**
+     * Part one of migrating [DraftEntity.scheduledAt] from String to Long.
+     *
+     * Copies existing data from `scheduledAt` into `scheduledAtLong`.
+     */
+    class MIGRATE_6_7 : AutoMigrationSpec {
+        @SuppressLint("ConstantLocale")
+        private val iso8601 = SimpleDateFormat(
+            "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
+            Locale.getDefault(),
+        ).apply {
+            timeZone = TimeZone.getTimeZone("UTC")
+        }
+
+        override fun onPostMigrate(db: SupportSQLiteDatabase) {
+            db.beginTransaction()
+
+            val draftCursor = db.query("SELECT id, scheduledAt FROM DraftEntity")
+            with(draftCursor) {
+                while (moveToNext()) {
+                    val scheduledAt = getStringOrNull(1) ?: continue
+
+                    // Parse the string representation to a Date. Ignore errors, they
+                    // shouldn't be possible.
+                    val scheduledDate = runCatching { iso8601.parse(scheduledAt) }.getOrNull()
+                        ?: continue
+
+                    // Dates are stored as Long, see Converters.dateToLong.
+                    val values = ContentValues().apply {
+                        put("scheduledAtLong", scheduledDate.time)
+                    }
+
+                    val draftId = getInt(0)
+                    db.update("DraftEntity", CONFLICT_ABORT, values, "id = ?", arrayOf(draftId))
+                }
+            }
+
+            db.setTransactionSuccessful()
+            db.endTransaction()
+        }
+    }
+
+    /**
+     * Completes the migration started in [MIGRATE_6_7]. SQLite on Android can't
+     * drop/rename columns, so use Room's annotations to generate the code to do this.
+     */
+    @DeleteColumn("DraftEntity", "scheduledAt")
+    @RenameColumn("DraftEntity", "scheduledAtLong", "scheduledAt")
+    class MIGRATE_7_8 : AutoMigrationSpec
 }

core/database/src/main/kotlin/app/pachli/core/database/model/DraftEntity.kt

@@ -29,6 +29,7 @@ import app.pachli.core.network.model.NewPoll
 import app.pachli.core.network.model.Status
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import java.util.Date
 import kotlinx.parcelize.Parcelize
 
 @Entity
@@ -45,7 +46,7 @@ data class DraftEntity(
     val poll: NewPoll?,
     val failedToSend: Boolean,
     val failedToSendNew: Boolean,
-    val scheduledAt: String?,
+    val scheduledAt: Date?,
     val language: String?,
     val statusId: String?,
 )

core/navigation/src/main/kotlin/app/pachli/core/navigation/Navigation.kt

@@ -38,6 +38,7 @@ import app.pachli.core.network.model.NewPoll
 import app.pachli.core.network.model.Notification
 import app.pachli.core.network.model.Status
 import com.gaelmarhic.quadrant.QuadrantConstants
+import java.util.Date
 import kotlinx.parcelize.Parcelize
 
 private const val EXTRA_PACHLI_ACCOUNT_ID = "app.pachli.EXTRA_PACHLI_ACCOUNT_ID"
@@ -147,7 +148,7 @@ class ComposeActivityIntent(context: Context) : Intent() {
         val replyingStatusContent: String? = null,
         val mediaAttachments: List<Attachment>? = null,
         val draftAttachments: List<DraftAttachment>? = null,
-        val scheduledAt: String? = null,
+        val scheduledAt: Date? = null,
         val sensitive: Boolean? = null,
         val poll: NewPoll? = null,
         val modifiedInitialState: Boolean? = null,

core/network/src/main/kotlin/app/pachli/core/network/model/NewStatus.kt

@@ -19,6 +19,7 @@ package app.pachli.core.network.model
 import android.os.Parcelable
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import java.util.Date
 import kotlinx.parcelize.Parcelize
 
 @JsonClass(generateAdapter = true)
@@ -30,7 +31,7 @@ data class NewStatus(
     val sensitive: Boolean,
     @Json(name = "media_ids") val mediaIds: List<String>?,
     @Json(name = "media_attributes") val mediaAttributes: List<MediaAttribute>?,
-    @Json(name = "scheduled_at") val scheduledAt: String?,
+    @Json(name = "scheduled_at") val scheduledAt: Date?,
     val poll: NewPoll?,
     val language: String?,
 )

core/network/src/main/kotlin/app/pachli/core/network/model/ScheduledStatus.kt

@@ -18,11 +18,12 @@ package app.pachli.core.network.model
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import java.util.Date
 
 @JsonClass(generateAdapter = true)
 data class ScheduledStatus(
     val id: String,
-    @Json(name = "scheduled_at") val scheduledAt: String,
+    @Json(name = "scheduled_at") val scheduledAt: Date,
     val params: StatusParams,
     @Json(name = "media_attachments") val mediaAttachments: List<Attachment>,
 )