Fix notifying about old "new" streams

app/src/androidTest/java/org/schabi/newpipe/database/FeedDAOTest.kt

@@ -0,0 +1,124 @@
+package org.schabi.newpipe.database
+
+import android.content.Context
+import androidx.room.Room
+import androidx.test.core.app.ApplicationProvider
+import io.reactivex.rxjava3.core.Single
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Before
+import org.junit.Test
+import org.schabi.newpipe.database.feed.dao.FeedDAO
+import org.schabi.newpipe.database.feed.model.FeedEntity
+import org.schabi.newpipe.database.feed.model.FeedGroupEntity
+import org.schabi.newpipe.database.stream.StreamWithState
+import org.schabi.newpipe.database.stream.dao.StreamDAO
+import org.schabi.newpipe.database.stream.model.StreamEntity
+import org.schabi.newpipe.database.subscription.SubscriptionDAO
+import org.schabi.newpipe.database.subscription.SubscriptionEntity
+import org.schabi.newpipe.extractor.ServiceList
+import org.schabi.newpipe.extractor.channel.ChannelInfo
+import org.schabi.newpipe.extractor.stream.StreamType
+import java.io.IOException
+import java.time.OffsetDateTime
+import kotlin.streams.toList
+
+class FeedDAOTest {
+    private lateinit var db: AppDatabase
+    private lateinit var feedDAO: FeedDAO
+    private lateinit var streamDAO: StreamDAO
+    private lateinit var subscriptionDAO: SubscriptionDAO
+
+    private val serviceId = ServiceList.YouTube.serviceId
+
+    private val stream1 = StreamEntity(1, serviceId, "https://youtube.com/watch?v=1", "stream 1", StreamType.VIDEO_STREAM, 1000, "channel-1", "https://youtube.com/channel/1", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-01-01", OffsetDateTime.parse("2023-01-01T00:00:00Z"))
+    private val stream2 = StreamEntity(2, serviceId, "https://youtube.com/watch?v=2", "stream 2", StreamType.VIDEO_STREAM, 1000, "channel-1", "https://youtube.com/channel/1", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-01-02", OffsetDateTime.parse("2023-01-02T00:00:00Z"))
+    private val stream3 = StreamEntity(3, serviceId, "https://youtube.com/watch?v=3", "stream 3", StreamType.LIVE_STREAM, 1000, "channel-1", "https://youtube.com/channel/1", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-01-03", OffsetDateTime.parse("2023-01-03T00:00:00Z"))
+    private val stream4 = StreamEntity(4, serviceId, "https://youtube.com/watch?v=4", "stream 4", StreamType.VIDEO_STREAM, 1000, "channel-2", "https://youtube.com/channel/2", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-08-10", OffsetDateTime.parse("2023-08-10T00:00:00Z"))
+    private val stream5 = StreamEntity(5, serviceId, "https://youtube.com/watch?v=5", "stream 5", StreamType.VIDEO_STREAM, 1000, "channel-2", "https://youtube.com/channel/2", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-08-20", OffsetDateTime.parse("2023-08-20T00:00:00Z"))
+    private val stream6 = StreamEntity(6, serviceId, "https://youtube.com/watch?v=6", "stream 6", StreamType.VIDEO_STREAM, 1000, "channel-3", "https://youtube.com/channel/3", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-09-01", OffsetDateTime.parse("2023-09-01T00:00:00Z"))
+    private val stream7 = StreamEntity(7, serviceId, "https://youtube.com/watch?v=7", "stream 7", StreamType.VIDEO_STREAM, 1000, "channel-4", "https://youtube.com/channel/4", "https://i.ytimg.com/vi/1/hqdefault.jpg", 100, "2023-08-10", OffsetDateTime.parse("2023-08-10T00:00:00Z"))
+
+    private val allStreams = listOf(
+        stream1, stream2, stream3, stream4, stream5, stream6, stream7
+    )
+
+    @Before
+    fun createDb() {
+        val context = ApplicationProvider.getApplicationContext<Context>()
+        db = Room.inMemoryDatabaseBuilder(
+            context, AppDatabase::class.java
+        ).build()
+        feedDAO = db.feedDAO()
+        streamDAO = db.streamDAO()
+        subscriptionDAO = db.subscriptionDAO()
+    }
+
+    @After
+    @Throws(IOException::class)
+    fun closeDb() {
+        db.close()
+    }
+
+    @Test
+    fun testUnlinkStreamsOlderThan_KeepOne() {
+        setupUnlinkDelete("2023-08-15T00:00:00Z")
+        val streams = feedDAO.getStreams(
+            FeedGroupEntity.GROUP_ALL_ID, includePlayed = true, includePartiallyPlayed = true, null
+        )
+            .blockingGet()
+        val allowedStreams = listOf(stream3, stream5, stream6, stream7)
+        assertEqual(streams, allowedStreams)
+    }
+
+    @Test
+    fun testUnlinkStreamsOlderThan_KeepMultiple() {
+        setupUnlinkDelete("2023-08-01T00:00:00Z")
+        val streams = feedDAO.getStreams(
+            FeedGroupEntity.GROUP_ALL_ID, includePlayed = true, includePartiallyPlayed = true, null
+        )
+            .blockingGet()
+        val allowedStreams = listOf(stream3, stream4, stream5, stream6, stream7)
+        assertEqual(streams, allowedStreams)
+    }
+
+    private fun assertEqual(streams: List<StreamWithState>?, allowedStreams: List<StreamEntity>) {
+        assertNotNull(streams)
+        assertEquals(allowedStreams, streams!!.stream().map { it.stream }.toList().sortedBy { it.uid })
+    }
+
+    private fun setupUnlinkDelete(time: String) {
+        clearAndFillTables()
+        Single.fromCallable {
+            feedDAO.unlinkStreamsOlderThan(OffsetDateTime.parse(time))
+        }.blockingSubscribe()
+        Single.fromCallable {
+            streamDAO.deleteOrphans()
+        }.blockingSubscribe()
+    }
+
+    private fun clearAndFillTables() {
+        db.clearAllTables()
+        streamDAO.insertAll(allStreams)
+        subscriptionDAO.insertAll(
+            listOf(
+                SubscriptionEntity.from(ChannelInfo(serviceId, "1", "https://youtube.com/channel/1", "https://youtube.com/channel/1", "channel-1")),
+                SubscriptionEntity.from(ChannelInfo(serviceId, "2", "https://youtube.com/channel/2", "https://youtube.com/channel/2", "channel-2")),
+                SubscriptionEntity.from(ChannelInfo(serviceId, "3", "https://youtube.com/channel/3", "https://youtube.com/channel/3", "channel-3")),
+                SubscriptionEntity.from(ChannelInfo(serviceId, "4", "https://youtube.com/channel/4", "https://youtube.com/channel/4", "channel-4")),
+            )
+        )
+        feedDAO.insertAll(
+            listOf(
+                FeedEntity(1, 1),
+                FeedEntity(2, 1),
+                FeedEntity(3, 1),
+                FeedEntity(4, 2),
+                FeedEntity(5, 2),
+                FeedEntity(6, 3),
+                FeedEntity(7, 4),
+            )
+        )
+    }
+}

app/src/main/java/org/schabi/newpipe/database/feed/dao/FeedDAO.kt

@@ -93,18 +93,28 @@ abstract class FeedDAO {
         uploadDateBefore: OffsetDateTime?
     ): Maybe<List<StreamWithState>>
 
+    /**
+     * Remove links to streams that are older than the given date
+     * **but keep at least one stream per uploader**.
+     *
+     * One stream per uploader is kept because it is needed as reference
+     * when fetching new streams to check if they are new or not.
+     * @param offsetDateTime the newest date to keep, older streams are removed
+     */
     @Query(
         """
-        DELETE FROM feed WHERE
-
-        feed.stream_id IN (
-            SELECT s.uid FROM streams s
-
-            INNER JOIN feed f
-            ON s.uid = f.stream_id
-
-            WHERE s.upload_date < :offsetDateTime
-        )
+        DELETE FROM feed
+        WHERE feed.stream_id IN (SELECT uid from (
+              SELECT s.uid,
+              (SELECT MAX(upload_date)
+                    FROM streams
+                    WHERE uploader_url = s.uploader_url) max_upload_date
+              FROM streams s
+              INNER JOIN feed f
+              ON s.uid = f.stream_id
+
+              WHERE s.upload_date < :offsetDateTime
+              AND   s.upload_date <> max_upload_date))
         """
     )
     abstract fun unlinkStreamsOlderThan(offsetDateTime: OffsetDateTime)