feat: Improve announcements API (#192)

Announcements can have tags now instead of being grouped into a single channel. You can get an announcement using its ID. You can page announcements and filter them by tags and whether they are archived. You can see a list of all available tags. Some route API overhaul.

Author: oSumAtrIX

README.md

@@ -75,7 +75,7 @@ with updates and ReVanced Patches.
 
 Some of the features ReVanced API include:
 
-- 📢 **Announcements**: Post and get announcements grouped by channels
+- 📢 **Announcements**: Post and get announcements
 - ℹ️ **About**: Get more information such as a description, ways to donate to, 
 and links of the hoster of ReVanced API
 - 🧩 **Patches**: Get the latest updates of ReVanced Patches, directly from ReVanced API

build.gradle.kts

@@ -48,6 +48,12 @@ kotlin {
     }
 }
 
+tasks {
+    test {
+        useJUnitPlatform()
+    }
+}
+
 repositories {
     mavenCentral()
     google()
@@ -98,6 +104,8 @@ dependencies {
     implementation(libs.caffeine)
     implementation(libs.bouncy.castle.provider)
     implementation(libs.bouncy.castle.pgp)
+
+    testImplementation(kotlin("test"))
 }
 
 // The maven-publish plugin is necessary to make signing work.

src/main/kotlin/app/revanced/api/configuration/repository/AnnouncementRepository.kt

@@ -1,10 +1,10 @@
 package app.revanced.api.configuration.repository
 
-import app.revanced.api.configuration.schema.APIAnnouncement
-import app.revanced.api.configuration.schema.APIResponseAnnouncement
-import app.revanced.api.configuration.schema.APIResponseAnnouncementId
+import app.revanced.api.configuration.schema.ApiAnnouncement
+import app.revanced.api.configuration.schema.ApiAnnouncementTag
+import app.revanced.api.configuration.schema.ApiResponseAnnouncement
+import app.revanced.api.configuration.schema.ApiResponseAnnouncementId
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.awaitAll
 import kotlinx.coroutines.runBlocking
 import kotlinx.datetime.*
 import org.jetbrains.exposed.dao.IntEntity
@@ -15,126 +15,175 @@ import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.kotlin.datetime.CurrentDateTime
 import org.jetbrains.exposed.sql.kotlin.datetime.datetime
 import org.jetbrains.exposed.sql.transactions.experimental.newSuspendedTransaction
-import org.jetbrains.exposed.sql.transactions.experimental.suspendedTransactionAsync
+import java.time.LocalDateTime
 
 internal class AnnouncementRepository {
-    // This is better than doing a maxByOrNull { it.id }.
+    // This is better than doing a maxByOrNull { it.id } on every request.
     private var latestAnnouncement: Announcement? = null
-    private val latestAnnouncementByChannel = mutableMapOf<String, Announcement>()
-
-    private fun updateLatestAnnouncement(new: Announcement) {
-        if (latestAnnouncement?.id?.value == new.id.value) {
-            latestAnnouncement = new
-            latestAnnouncementByChannel[new.channel ?: return] = new
-        }
-    }
+    private val latestAnnouncementByTag = mutableMapOf<Int, Announcement>()
 
     init {
         runBlocking {
             transaction {
-                SchemaUtils.create(Announcements, Attachments)
+                SchemaUtils.create(
+                    Announcements,
+                    Attachments,
+                    Tags,
+                    AnnouncementTags,
+                )
 
-                // Initialize the latest announcement.
-                latestAnnouncement = Announcement.all().onEach {
-                    latestAnnouncementByChannel[it.channel ?: return@onEach] = it
-                }.maxByOrNull { it.id } ?: return@transaction
+                initializeLatestAnnouncements()
             }
         }
     }
 
-    suspend fun all() = transaction {
-        Announcement.all().map { it.toApi() }
+    private fun initializeLatestAnnouncements() {
+        latestAnnouncement = Announcement.all().orderBy(Announcements.id to SortOrder.DESC).firstOrNull()
+
+        Tag.all().map { it.id.value }.forEach(::updateLatestAnnouncementForTag)
     }
 
-    suspend fun all(channel: String) = transaction {
-        Announcement.find { Announcements.channel eq channel }.map { it.toApi() }
+    private fun updateLatestAnnouncement(new: Announcement) {
+        if (latestAnnouncement == null || latestAnnouncement!!.id.value <= new.id.value) {
+            latestAnnouncement = new
+            new.tags.forEach { tag -> latestAnnouncementByTag[tag.id.value] = new }
+        }
     }
 
-    suspend fun delete(id: Int) = transaction {
-        val announcement = Announcement.findById(id) ?: return@transaction
+    private fun updateLatestAnnouncementForTag(tag: Int) {
+        val latestAnnouncementForTag = AnnouncementTags.select(AnnouncementTags.announcement)
+            .where { AnnouncementTags.tag eq tag }
+            .map { it[AnnouncementTags.announcement] }
+            .mapNotNull { Announcement.findById(it) }
+            .maxByOrNull { it.id }
 
-        announcement.delete()
+        latestAnnouncementForTag?.let { latestAnnouncementByTag[tag] = it }
+    }
 
-        // In case the latest announcement was deleted, query the new latest announcement again.
-        if (latestAnnouncement?.id?.value == id) {
-            latestAnnouncement = Announcement.all().maxByOrNull { it.id }
+    suspend fun latest() = transaction {
+        latestAnnouncement.toApiResponseAnnouncement()
+    }
 
-            // If no latest announcement was found, remove it from the channel map.
-            if (latestAnnouncement == null) {
-                latestAnnouncementByChannel.remove(announcement.channel)
-            } else {
-                latestAnnouncementByChannel[latestAnnouncement!!.channel ?: return@transaction] = latestAnnouncement!!
-            }
-        }
+    suspend fun latest(tags: Set<Int>) = transaction {
+        tags.mapNotNull { tag -> latestAnnouncementByTag[tag] }.toApiAnnouncement()
     }
 
-    fun latest() = latestAnnouncement?.toApi()
+    fun latestId() = latestAnnouncement?.id?.value.toApiResponseAnnouncementId()
 
-    fun latest(channel: String) = latestAnnouncementByChannel[channel]?.toApi()
+    fun latestId(tags: Set<Int>) =
+        tags.map { tag -> latestAnnouncementByTag[tag]?.id?.value }.toApiResponseAnnouncementId()
 
-    fun latestId() = latest()?.id?.toApi()
+    suspend fun paged(cursor: Int, count: Int, tags: Set<Int>?, archived: Boolean) = transaction {
+        Announcement.find {
+            fun idLessEq() = Announcements.id lessEq cursor
+            fun archivedAtIsNull() = Announcements.archivedAt.isNull()
+            fun archivedAtGreaterNow() = Announcements.archivedAt greater LocalDateTime.now().toKotlinLocalDateTime()
+
+            if (tags == null) {
+                if (archived) {
+                    idLessEq()
+                } else {
+                    idLessEq() and (archivedAtIsNull() or archivedAtGreaterNow())
+                }
+            } else {
+                fun archivedAtGreaterOrNullOrTrue() = if (archived) {
+                    Op.TRUE
+                } else {
+                    archivedAtIsNull() or archivedAtGreaterNow()
+                }
 
-    fun latestId(channel: String) = latest(channel)?.id?.toApi()
+                fun hasTags() = tags.mapNotNull { Tag.findById(it)?.id }.let { tags ->
+                    Announcements.id inSubQuery Announcements.leftJoin(AnnouncementTags)
+                        .select(AnnouncementTags.announcement)
+                        .where { AnnouncementTags.tag inList tags }
+                        .withDistinct()
+                }
 
-    suspend fun archive(
-        id: Int,
-        archivedAt: LocalDateTime?,
-    ) = transaction {
-        Announcement.findByIdAndUpdate(id) {
-            it.archivedAt = archivedAt ?: java.time.LocalDateTime.now().toKotlinLocalDateTime()
-        }?.also(::updateLatestAnnouncement)
+                idLessEq() and archivedAtGreaterOrNullOrTrue() and hasTags()
+            }
+        }.orderBy(Announcements.id to SortOrder.DESC).limit(count).toApiAnnouncement()
     }
 
-    suspend fun unarchive(id: Int) = transaction {
-        Announcement.findByIdAndUpdate(id) {
-            it.archivedAt = null
-        }?.also(::updateLatestAnnouncement)
+    suspend fun get(id: Int) = transaction {
+        Announcement.findById(id).toApiResponseAnnouncement()
     }
 
-    suspend fun new(new: APIAnnouncement) = transaction {
+    suspend fun new(new: ApiAnnouncement) = transaction {
         Announcement.new {
             author = new.author
             title = new.title
             content = new.content
-            channel = new.channel
             archivedAt = new.archivedAt
             level = new.level
-        }.also { newAnnouncement ->
-            new.attachmentUrls.map { newUrl ->
-                suspendedTransactionAsync {
-                    Attachment.new {
-                        url = newUrl
-                        announcement = newAnnouncement
-                    }
+            tags = SizedCollection(
+                new.tags.map { tag -> Tag.find { Tags.name eq tag }.firstOrNull() ?: Tag.new { name = tag } },
+            )
+        }.apply {
+            new.attachments.map { attachmentUrl ->
+                Attachment.new {
+                    url = attachmentUrl
+                    announcement = this@apply
                 }
-            }.awaitAll()
-        }.also(::updateLatestAnnouncement)
+            }
+        }.let(::updateLatestAnnouncement)
     }
 
-    suspend fun update(id: Int, new: APIAnnouncement) = transaction {
+    suspend fun update(id: Int, new: ApiAnnouncement) = transaction {
         Announcement.findByIdAndUpdate(id) {
             it.author = new.author
             it.title = new.title
             it.content = new.content
-            it.channel = new.channel
             it.archivedAt = new.archivedAt
             it.level = new.level
-        }?.also { newAnnouncement ->
-            newAnnouncement.attachments.map {
-                suspendedTransactionAsync {
-                    it.delete()
-                }
-            }.awaitAll()
-
-            new.attachmentUrls.map { newUrl ->
-                suspendedTransactionAsync {
-                    Attachment.new {
-                        url = newUrl
-                        announcement = newAnnouncement
-                    }
+
+            // Get the old tags, create new tags if they don't exist,
+            // and delete tags that are not in the new tags, after updating the announcement.
+            val oldTags = it.tags.toList()
+            val updatedTags = new.tags.map { name ->
+                Tag.find { Tags.name eq name }.firstOrNull() ?: Tag.new { this.name = name }
+            }
+            it.tags = SizedCollection(updatedTags)
+            oldTags.forEach { tag ->
+                if (tag in updatedTags || !tag.announcements.empty()) return@forEach
+                tag.delete()
+            }
+
+            // Delete old attachments and create new attachments.
+            it.attachments.forEach { attachment -> attachment.delete() }
+            new.attachments.map { attachment ->
+                Attachment.new {
+                    url = attachment
+                    announcement = it
                 }
-            }.awaitAll()
-        }?.also(::updateLatestAnnouncement)
+            }
+        }?.let(::updateLatestAnnouncement) ?: Unit
+    }
+
+    suspend fun delete(id: Int) = transaction {
+        val announcement = Announcement.findById(id) ?: return@transaction
+
+        // Delete the tag if no other announcements are referencing it.
+        // One count means that the announcement is the only one referencing the tag.
+        announcement.tags.filter { tag -> tag.announcements.count() == 1L }.forEach { tag ->
+            latestAnnouncementByTag -= tag.id.value
+            tag.delete()
+        }
+
+        announcement.delete()
+
+        // If the deleted announcement is the latest announcement, set the new latest announcement.
+        if (latestAnnouncement?.id?.value == id) {
+            latestAnnouncement = Announcement.all().orderBy(Announcements.id to SortOrder.DESC).firstOrNull()
+        }
+
+        // The new announcement may be the latest for a specific tag. Set the new latest announcement for that tag.
+        latestAnnouncementByTag.keys.forEach { tag ->
+            updateLatestAnnouncementForTag(tag)
+        }
+    }
+
+    suspend fun tags() = transaction {
+        Tag.all().toList().toApiTag()
     }
 
     private suspend fun <T> transaction(statement: suspend Transaction.() -> T) =
@@ -144,7 +193,6 @@ internal class AnnouncementRepository {
         val author = varchar("author", 32).nullable()
         val title = varchar("title", 64)
         val content = text("content").nullable()
-        val channel = varchar("channel", 16).nullable()
         val createdAt = datetime("createdAt").defaultExpression(CurrentDateTime)
         val archivedAt = datetime("archivedAt").nullable()
         val level = integer("level")
@@ -155,14 +203,27 @@ internal class AnnouncementRepository {
         val announcement = reference("announcement", Announcements, onDelete = ReferenceOption.CASCADE)
     }
 
+    private object Tags : IntIdTable() {
+        val name = varchar("name", 16).uniqueIndex()
+    }
+
+    private object AnnouncementTags : Table() {
+        val tag = reference("tag", Tags, onDelete = ReferenceOption.CASCADE)
+        val announcement = reference("announcement", Announcements, onDelete = ReferenceOption.CASCADE)
+
+        init {
+            uniqueIndex(tag, announcement)
+        }
+    }
+
     class Announcement(id: EntityID<Int>) : IntEntity(id) {
         companion object : IntEntityClass<Announcement>(Announcements)
 
         var author by Announcements.author
         var title by Announcements.title
         var content by Announcements.content
         val attachments by Attachment referrersOn Attachments.announcement
-        var channel by Announcements.channel
+        var tags by Tag via AnnouncementTags
         var createdAt by Announcements.createdAt
         var archivedAt by Announcements.archivedAt
         var level by Announcements.level
@@ -175,17 +236,32 @@ internal class AnnouncementRepository {
         var announcement by Announcement referencedOn Attachments.announcement
     }
 
-    private fun Announcement.toApi() = APIResponseAnnouncement(
-        id.value,
-        author,
-        title,
-        content,
-        attachments.map { it.url },
-        channel,
-        createdAt,
-        archivedAt,
-        level,
-    )
+    class Tag(id: EntityID<Int>) : IntEntity(id) {
+        companion object : IntEntityClass<Tag>(Tags)
+
+        var name by Tags.name
+        var announcements by Announcement via AnnouncementTags
+    }
+
+    private fun Announcement?.toApiResponseAnnouncement() = this?.let {
+        ApiResponseAnnouncement(
+            id.value,
+            author,
+            title,
+            content,
+            attachments.map { it.url },
+            tags.map { it.id.value },
+            createdAt,
+            archivedAt,
+            level,
+        )
+    }
+
+    private fun Iterable<Announcement>.toApiAnnouncement() = map { it.toApiResponseAnnouncement()!! }
+
+    private fun Iterable<Tag>.toApiTag() = map { ApiAnnouncementTag(it.id.value, it.name) }
+
+    private fun Int?.toApiResponseAnnouncementId() = this?.let { ApiResponseAnnouncementId(this) }
 
-    private fun Int.toApi() = APIResponseAnnouncementId(this)
+    private fun Iterable<Int?>.toApiResponseAnnouncementId() = map { it.toApiResponseAnnouncementId() }
 }