🐛 fix firestore timestamp decoding by normalizing the data

The firestore module was merged with the common module, we try to find a better way

common/build.gradle.kts

@@ -1,19 +1,42 @@
 import java.util.Properties
 
 plugins {
-    alias(libs.plugins.jetbrains.kotlin.jvm)
+    alias(libs.plugins.android.library)
+    alias(libs.plugins.jetbrains.kotlin.android)
     alias(libs.plugins.kotlin.serialization)
     `maven-publish`
     signing
 }
 
 version = versionString
 
+android {
+    namespace = "de.sipgate.federmappe.firestore"
+    compileSdk = 34
+    defaultConfig.minSdk = 23
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
 dependencies {
+    compileOnly(libs.firebase.firestore)
     compileOnly(libs.kotlinx.serialization)
 
     implementation(libs.kotlinx.datetime)
 
+    testImplementation(libs.firebase.firestore)
     testImplementation(libs.kotlin.test)
     testImplementation(libs.kotlinx.serialization)
     testImplementation(libs.mockk.agent)
@@ -62,7 +85,7 @@ publishing {
         }
 
         afterEvaluate {
-            from(components["java"])
+            from(components["release"])
         }
     }
 
@@ -78,10 +101,6 @@ publishing {
     }
 }
 
-kotlin {
-    jvmToolchain(8)
-}
-
 signing {
     val signingKey: String? by project
     val signingPassword: String? by project

common/src/main/kotlin/de/sipgate/federmappe/common/decoder/StringMapToObjectDecoder.kt

@@ -1,6 +1,8 @@
 package de.sipgate.federmappe.common.decoder
 
 import de.sipgate.federmappe.common.helper.sortByPrio
+import de.sipgate.federmappe.firestore.normalizeStringMap
+import de.sipgate.federmappe.firestore.normalizeStringMapNullable
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.SerializationException
 import kotlinx.serialization.descriptors.PolymorphicKind
@@ -64,7 +66,8 @@ class StringMapToObjectDecoder(
             return this
         }
 
-        val value = data[key]
+        val normalizedData = data.normalizeStringMapNullable()
+        val value = normalizedData[key]
         val valueDescriptor = descriptor.kind
 
         when (valueDescriptor) {

firestore/src/main/java/de/sipgate/federmappe/firestore/QuerySnapshotExt.kt → common/src/main/kotlin/de/sipgate/federmappe/common/firestore/QuerySnapshotExt.kt

@@ -29,3 +29,10 @@ fun Map<String, Any>.normalizeStringMap(): Map<String, Any> = mapValues {
         else -> value
     }
 }
+
+fun Map<String, Any?>.normalizeStringMapNullable(): Map<String, Any?> = mapValues {
+    when (val value = it.value) {
+        is Timestamp -> value.toDecodableTimestamp()
+        else -> value
+    }
+}

common/src/test/kotlin/de/sipgate/federmappe/common/FirestoreTimestampToDecodableTimestampTest.kt

@@ -0,0 +1,78 @@
+package de.sipgate.federmappe.common
+
+import com.google.firebase.Timestamp
+import de.sipgate.federmappe.common.decoder.StringMapToObjectDecoder
+import de.sipgate.federmappe.firestore.types.toDecodableTimestamp
+import kotlinx.datetime.Instant
+import kotlinx.datetime.serializers.InstantComponentSerializer
+import kotlinx.datetime.toJavaInstant
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.modules.SerializersModule
+import kotlinx.serialization.modules.contextual
+import kotlinx.serialization.serializer
+import java.util.Date
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+
+class FirestoreTimestampToDecodableTimestampTest {
+
+    @Test
+    fun timestampWithNanosecondPrecisionIsConvertedSuccessfully() {
+        val expectedInstant = Instant.fromEpochSeconds(1716823455, 854)
+
+        val timestamp = Timestamp(expectedInstant.toJavaInstant())
+
+        val result = timestamp.toDecodableTimestamp()
+        assertEquals(expectedInstant.epochSeconds, result["epochSeconds"])
+        assertEquals(expectedInstant.nanosecondsOfSecond.toLong(), result["nanosecondsOfSecond"])
+    }
+
+    @Test
+    fun timestampWithSecondPrecisionIsConvertedSuccessfully() {
+        val expectedDate = Date.from(Instant.fromEpochSeconds(1716823455).toJavaInstant())
+        val expectedEpochSeconds = expectedDate.time / 1000
+
+        val timestamp = Timestamp(expectedDate)
+
+        val result = timestamp.toDecodableTimestamp()
+
+        assertEquals(expectedEpochSeconds, result["epochSeconds"])
+        assertEquals(0L, result["nanosecondsOfSecond"])
+    }
+
+    @OptIn(ExperimentalSerializationApi::class)
+    @Test
+    fun firestoreTimestampIsDecodedCorrectly() {
+        // Arrange
+        val expectedInstant = Instant.fromEpochSeconds(1716823455)
+        val expectedDate = Date.from(expectedInstant.toJavaInstant())
+        val timestamp = Timestamp(expectedDate)
+
+        @Serializable
+        data class MockLocalDataClass(
+            @Contextual
+            val createdAt: Instant
+        )
+
+        val serializer = serializer<MockLocalDataClass>()
+
+        val data = mapOf<String, Any?>("createdAt" to timestamp)
+
+        // Act
+        val result =
+            serializer.deserialize(
+                StringMapToObjectDecoder(
+                    data,
+                    serializersModule = SerializersModule { contextual(InstantComponentSerializer) }
+                ),
+            )
+
+        // Assert
+        assertEquals(expectedInstant, result.createdAt)
+        assertIs<MockLocalDataClass>(result)
+    }
+}