feat: add initial xplatform backup serialization

This commit introduces a new multiplatform backup feature including export and import capabilities. It adds data classes, serialization, tests, and Gradle dependencies to support cross-platform backup data handling, including proper ProtoBuf serialization.

backup/build.gradle.kts

@@ -77,36 +77,42 @@ kotlin {
         val androidMain by getting {
             dependsOn(nonJsMain)
         }
+        val androidInstrumentedTest by getting {
+            dependsOn(nonJsTest)
+        }
         val jvmMain by getting {
             dependsOn(nonJsMain)
         }
-
-        val iosX64Main by getting {
+        val jvmTest by getting {
+            dependsOn(nonJsTest)
+        }
+        val appleMain by getting {
             dependsOn(nonJsMain)
+        }
+        val appleTest by getting {
+            dependsOn(nonJsTest)
+        }
+        val iosX64Main by getting {
             dependencies {
                 implementation(libs.pbandk.runtime.iosX64)
             }
         }
         val iosArm64Main by getting {
-            dependsOn(nonJsMain)
             dependencies {
                 implementation(libs.pbandk.runtime.iosArm64)
             }
         }
         val iosSimulatorArm64Main by getting {
-            dependsOn(nonJsMain)
             dependencies {
                 implementation(libs.pbandk.runtime.iosSimulatorArm64)
             }
         }
         val macosX64Main by getting {
-            dependsOn(nonJsMain)
             dependencies {
                 implementation(libs.pbandk.runtime.macX64)
             }
         }
         val macosArm64Main by getting {
-            dependsOn(nonJsMain)
             dependencies {
                 implementation(libs.pbandk.runtime.macArm64)
             }

backup/src/commonMain/kotlin/com/wire/backup/MPBackup.kt

@@ -0,0 +1,25 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+package com.wire.backup
+
+import kotlin.js.JsExport
+
+@JsExport
+object MPBackup {
+    const val ZIP_ENTRY_DATA = "data.wmbu"
+}

backup/src/commonMain/kotlin/com/wire/backup/data/BackupData.kt

@@ -0,0 +1,105 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+@file:OptIn(ExperimentalObjCRefinement::class, ExperimentalObjCName::class)
+
+package com.wire.backup.data
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlin.experimental.ExperimentalObjCName
+import kotlin.experimental.ExperimentalObjCRefinement
+import kotlin.js.JsExport
+import kotlin.native.ObjCName
+import kotlin.native.ShouldRefineInSwift
+
+@JsExport
+class BackupData(
+    val metadata: BackupMetadata,
+    @ShouldRefineInSwift
+    val users: Array<BackupUser>,
+    @ShouldRefineInSwift
+    val conversations: Array<BackupConversation>,
+    @ShouldRefineInSwift
+    val messages: Array<BackupMessage>
+) {
+    @ObjCName("users")
+    val userList: List<BackupUser> get() = users.toList()
+
+    @ObjCName("conversations")
+    val conversationList: List<BackupConversation> get() = conversations.toList()
+
+    @ObjCName("messages")
+    val messageList: List<BackupMessage> get() = messages.toList()
+}
+
+@JsExport
+@Serializable
+data class BackupQualifiedId(
+    @SerialName("id")
+    val id: String,
+    @SerialName("domain")
+    val domain: String,
+) {
+    override fun toString() = "$id@$domain"
+
+    companion object {
+        private const val QUALIFIED_ID_COMPONENT_COUNT = 2
+
+        fun fromEncodedString(id: String): BackupQualifiedId? {
+            val components = id.split("@")
+            if (components.size != QUALIFIED_ID_COMPONENT_COUNT) return null
+            return BackupQualifiedId(components[0], components[1])
+        }
+    }
+}
+
+@JsExport
+data class BackupUser(
+    val id: BackupQualifiedId,
+    val name: String,
+    val handle: String,
+)
+
+@JsExport
+data class BackupConversation(
+    val id: BackupQualifiedId,
+    val name: String,
+)
+
+@JsExport
+data class BackupMessage(
+    val id: String,
+    val conversationId: BackupQualifiedId,
+    val senderUserId: BackupQualifiedId,
+    val senderClientId: String,
+    val creationDate: BackupDateTime,
+    val content: BackupMessageContent
+)
+
+expect class BackupDateTime
+
+expect fun BackupDateTime(timestampMillis: Long): BackupDateTime
+expect fun BackupDateTime.toLongMilliseconds(): Long
+
+@JsExport
+sealed class BackupMessageContent {
+    data class Text(val text: String) : BackupMessageContent()
+
+    // TODO: Not _yet_ implemented
+    data class Asset(val todo: String) : BackupMessageContent()
+}

backup/src/commonMain/kotlin/com/wire/backup/data/BackupMetadata.kt

@@ -0,0 +1,29 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+
+package com.wire.backup.data
+
+import kotlin.js.JsExport
+
+@JsExport
+data class BackupMetadata(
+    val version: String,
+    val userId: BackupQualifiedId,
+    val creationTime: BackupDateTime,
+    val clientId: String?
+)

backup/src/commonMain/kotlin/com/wire/backup/data/Mapping.kt

@@ -0,0 +1,23 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+package com.wire.backup.data
+
+import com.wire.kalium.protobuf.backup.ExportedQualifiedId
+
+internal fun BackupQualifiedId.toProtoModel() = ExportedQualifiedId(id, domain)
+internal fun ExportedQualifiedId.toModel() = BackupQualifiedId(value, domain)

backup/src/commonMain/kotlin/com/wire/backup/dump/MPBackupExporter.kt

@@ -0,0 +1,113 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+package com.wire.backup.dump
+
+import com.wire.backup.data.BackupConversation
+import com.wire.backup.data.BackupMessage
+import com.wire.backup.data.BackupMessageContent
+import com.wire.backup.data.BackupQualifiedId
+import com.wire.backup.data.BackupUser
+import com.wire.backup.data.toLongMilliseconds
+import com.wire.backup.data.toProtoModel
+import com.wire.kalium.protobuf.backup.BackupData
+import com.wire.kalium.protobuf.backup.BackupInfo
+import com.wire.kalium.protobuf.backup.ExportUser
+import com.wire.kalium.protobuf.backup.ExportedConversation
+import com.wire.kalium.protobuf.backup.ExportedMessage
+import com.wire.kalium.protobuf.backup.ExportedText
+import kotlinx.datetime.Clock
+import pbandk.encodeToByteArray
+import kotlin.experimental.ExperimentalObjCName
+import kotlin.experimental.ExperimentalObjCRefinement
+import kotlin.js.JsExport
+import kotlin.native.ObjCName
+import kotlin.native.ShouldRefineInSwift
+
+/**
+ * Entity able to serialize [BackupData] entities, like [BackupMessage], [BackupConversation], [BackupUser]
+ * into a cross-platform [BackupData] format.
+ */
+@OptIn(ExperimentalObjCName::class, ExperimentalObjCRefinement::class)
+@JsExport
+abstract class CommonMPBackupExporter(
+    private val selfUserId: BackupQualifiedId
+) {
+    private val allUsers = mutableListOf<BackupUser>()
+    private val allConversations = mutableListOf<BackupConversation>()
+    private val allMessages = mutableListOf<BackupMessage>()
+
+    // TODO: Replace `ObjCName` with `JsName` in the future and flip it around.
+    //       Unfortunately the IDE doesn't understand this right now and
+    //       keeps complaining if making the other way around
+    @ObjCName("add")
+    fun addUser(user: BackupUser) {
+        allUsers.add(user)
+    }
+
+    @ObjCName("add")
+    fun addConversation(conversation: BackupConversation) {
+        allConversations.add(conversation)
+    }
+
+    @ObjCName("add")
+    fun addMessage(message: BackupMessage) {
+        allMessages.add(message)
+    }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    @ShouldRefineInSwift // Hidden in Swift
+    fun serialize(): ByteArray {
+        val backupData = BackupData(
+            BackupInfo(
+                platform = "Common",
+                version = "1.0",
+                userId = selfUserId.toProtoModel(),
+                creationTime = Clock.System.now().toEpochMilliseconds(),
+                clientId = "lol"
+            ),
+            allConversations.map { ExportedConversation(it.id.toProtoModel(), it.name) },
+            allMessages.map {
+                ExportedMessage(
+                    id = it.id,
+                    timeIso = it.creationDate.toLongMilliseconds(),
+                    senderUserId = it.senderUserId.toProtoModel(),
+                    senderClientId = it.senderClientId,
+                    conversationId = it.conversationId.toProtoModel(),
+                    content = when (val content = it.content) {
+                        is BackupMessageContent.Asset ->
+                            ExportedMessage.Content.Text(ExportedText("FAKE ASSET")) // TODO: Support assets
+                        is BackupMessageContent.Text ->
+                            ExportedMessage.Content.Text(ExportedText(content.text))
+                    }
+                )
+            },
+            allUsers.map {
+                ExportUser(
+                    id = it.id.toProtoModel(),
+                    name = it.name,
+                    handle = it.handle
+                )
+            },
+        )
+        return backupData.encodeToByteArray().also {
+            println("XPlatform Backup POC. Exported data bytes: ${it.toHexString()}")
+        }
+    }
+}
+
+expect class MPBackupExporter : CommonMPBackupExporter

backup/src/commonMain/kotlin/com/wire/backup/ingest/BackupImportResult.kt

@@ -0,0 +1,27 @@
+/*
+ * Wire
+ * Copyright (C) 2024 Wire Swiss GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+package com.wire.backup.ingest
+
+import com.wire.backup.data.BackupData
+import kotlin.js.JsExport
+
+@JsExport
+sealed class BackupImportResult {
+    data object ParsingFailure : BackupImportResult()
+    data class Success(val backupData: BackupData) : BackupImportResult()
+}