feat: introduce KotlinInstant type for Kotlin bindings

Author: MohamadJaara

crypto-ffi/bindings/android/build.gradle.kts

@@ -20,6 +20,7 @@ dependencies {
     implementation(kotlin("stdlib-jdk7"))
     implementation("${libs.jna.get()}@aar")
     implementation(libs.coroutines.core)
+    implementation(libs.kotlinx.datetime)
     implementation("androidx.annotation:annotation:1.9.1")
 
     androidTestImplementation(kotlin("test"))

crypto-ffi/bindings/gradle/libs.versions.toml

@@ -1,6 +1,7 @@
 [versions]
 kotlin = "1.9.25"
 coroutines = "1.7.3"
+kotlinx-datetime = "0.6.1"
 jna = "5.17.0"
 assertj = "3.24.2"
 espresso = "3.6.1"
@@ -29,3 +30,4 @@ espresso = { module = "androidx.test.espresso:espresso-core", version.ref = "esp
 android-junit = { module = "androidx.test.ext:junit", version.ref = "android-junit" }
 android-tools = { module = "com.android.tools.build:gradle", version.ref = "android-tools" }
 kotlin-gradle = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin-gradle" }
+kotlinx-datetime = { module = "org.jetbrains.kotlinx:kotlinx-datetime", version.ref = "kotlinx-datetime" }

crypto-ffi/bindings/jvm/build.gradle.kts

@@ -20,6 +20,7 @@ dependencies {
     implementation(kotlin("stdlib-jdk7"))
     implementation(libs.jna)
     implementation(libs.coroutines.core)
+    implementation(libs.kotlinx.datetime)
     testImplementation(kotlin("test"))
     testImplementation(libs.coroutines.test)
     testImplementation(libs.assertj.core)

crypto-ffi/src/timestamp.rs

@@ -0,0 +1,45 @@
+//! Custom timestamp type for UniFFI that maps to kotlinx.datetime.Instant in Kotlin
+/// the reason behind it is to unify the timestamp mapping between the JVM/Android bindings
+/// and the new Kotlin Multiplatform bindings.
+/// this can be removed once we fully migrate to Kotlin Multiplatform and
+/// stop generating JVM/Android bindings.
+
+#[cfg(not(target_family = "wasm"))]
+use std::time::{Duration, SystemTime};
+
+#[cfg(not(target_family = "wasm"))]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct KotlinInstant(pub SystemTime);
+
+#[cfg(not(target_family = "wasm"))]
+impl KotlinInstant {
+
+    pub fn new(time: SystemTime) -> Self {
+        Self(time)
+    }
+
+    pub fn from_epoch_secs(secs: u64) -> Self {
+        Self(SystemTime::UNIX_EPOCH + Duration::from_secs(secs))
+    }
+
+    pub fn into_inner(self) -> SystemTime {
+        self.0
+    }
+}
+
+#[cfg(not(target_family = "wasm"))]
+impl From<SystemTime> for KotlinInstant {
+    fn from(time: SystemTime) -> Self {
+        Self(time)
+    }
+}
+
+#[cfg(not(target_family = "wasm"))]
+impl From<KotlinInstant> for SystemTime {
+    fn from(instant: KotlinInstant) -> Self {
+        instant.0
+    }
+}
+
+#[cfg(not(target_family = "wasm"))]
+uniffi::custom_type!(KotlinInstant, SystemTime);

crypto-ffi/uniffi-android.toml

@@ -1,3 +1,13 @@
 [bindings.kotlin]
 android = true
 android_cleaner = true
+
+[bindings.kotlin.custom_types.KotlinInstant]
+imports = [
+  "kotlinx.datetime.Instant",
+  "kotlinx.datetime.toKotlinInstant",
+  "kotlinx.datetime.toJavaInstant",
+]
+type_name = "Instant"
+lift = "{}.toKotlinInstant()"
+lower = "{}.toJavaInstant()"

crypto-ffi/uniffi.toml

@@ -2,6 +2,16 @@
 package_name = "com.wire.crypto"
 cdylib_name = "core_crypto_ffi"
 
+[bindings.kotlin.custom_types.KotlinInstant]
+imports = [
+  "kotlinx.datetime.Instant",
+  "kotlinx.datetime.toKotlinInstant",
+  "kotlinx.datetime.toJavaInstant",
+]
+type_name = "Instant"
+lift = "{}.toKotlinInstant()"
+lower = "{}.toJavaInstant()"
+
 [bindings.swift]
 cdylib_name = "core_crypto_ffi"
 ffi_module_name = "LibCoreCrypto"