feat: introduce new pns models and wire kotlinx serialization to apply in libsession

libsession/build.gradle

@@ -1,6 +1,7 @@
 plugins {
     id 'com.android.library'
     id 'kotlin-android'
+    id 'kotlinx-serialization'
 }
 
 android {
@@ -41,6 +42,7 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
     implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlinVersion"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutinesVersion"
+    implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:$kotlinxJsonVersion"
     implementation "nl.komponents.kovenant:kovenant:$kovenantVersion"
     testImplementation "junit:junit:$junitVersion"
     testImplementation 'org.assertj:assertj-core:3.11.1'

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/notifications/Models.kt

@@ -0,0 +1,52 @@
+package org.session.libsession.messaging.sending_receiving.notifications
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class SubscriptionRequest(
+    /** the 33-byte account being subscribed to; typically a session ID */
+    val pubkey: String,
+    /** when the pubkey starts with 05 (i.e. a session ID) this is the ed25519 32-byte pubkey associated with the session ID */
+    val session_ed25519: String?,
+    /** 32-byte swarm authentication subkey; omitted (or null) when not using subkey auth (new closed groups) */
+    val subkey_tag: String?,
+    /** array of integer namespaces to subscribe to, **must be sorted in ascending order** */
+    val namespaces: List<Int>,
+    /** if provided and true then notifications will include the body of the message (as long as it isn't too large) */
+    val data: Boolean,
+    /** the signature unix timestamp in seconds, not ms */
+    val sig_ts: Long,
+    /** the 64-byte ed25519 signature */
+    val signature: String,
+    /** the string identifying the notification service, "firebase" for android (currently) */
+    val service: String,
+    /** dict of service-specific data, currently just "token" field with device-specific token but different services might have other requirements */
+    val service_info: Map<String, String>,
+    /** 32-byte encryption key; notification payloads sent to the device will be encrypted with XChaCha20-Poly1305 via libsodium using this key.
+     * persist it on device */
+    val enc_key: String
+)
+
+@Serializable
+data class SubscriptionResponse(
+    val error: Int?,
+    val message: String?,
+    val success: Boolean?,
+    val added: Boolean?,
+    val updated: Boolean?,
+) {
+    companion object {
+        /** invalid values, missing reuqired arguments etc, details in message */
+        const val UNPARSEABLE_ERROR = 1
+        /** the "service" value is not active / valid */
+        const val SERVICE_NOT_AVAILABLE = 2
+        /** something getting wrong internally talking to the backend */
+        const val SERVICE_TIMEOUT = 3
+        /** other error processing the subscription (details in the message) */
+        const val GENERIC_ERROR = 4
+    }
+    fun isSuccess() = success == true && error == null
+    fun errorInfo() = if (success == false && error != null) {
+        true to message
+    } else false to null
+}

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/notifications/PushNotificationAPI.kt

@@ -16,8 +16,8 @@ import org.session.libsignal.utilities.Log
 @SuppressLint("StaticFieldLeak")
 object PushNotificationAPI {
     val context = MessagingModuleConfiguration.shared.context
-    val server = "https://live.apns.getsession.org"
-    val serverPublicKey = "642a6585919742e5a2d4dc51244964fbcd8bcab2b75612407de58b810740d049"
+    val server = "https://push.getsession.org"
+    val serverPublicKey: String = TODO("get the new server pubkey here")
     private val maxRetryCount = 4
     private val tokenExpirationInterval = 12 * 60 * 60 * 1000