Refactor time access behind TimeSource

app/src/test/java/testhelpers/TestTimeSource.kt

@@ -0,0 +1,30 @@
+package testhelpers
+
+import eu.darken.capod.common.TimeSource
+import java.time.Duration
+import java.time.Instant
+
+class TestTimeSource(
+    var wallNow: Instant = Instant.parse("2026-01-01T00:00:00Z"),
+    var elapsedRealtimeMs: Long = 0L,
+    var elapsedRealtimeNanosValue: Long = 0L,
+    var uptimeMillisValue: Long = 0L,
+) : TimeSource {
+
+    override fun now(): Instant = wallNow
+
+    override fun currentTimeMillis(): Long = wallNow.toEpochMilli()
+
+    override fun elapsedRealtime(): Long = elapsedRealtimeMs
+
+    override fun elapsedRealtimeNanos(): Long = elapsedRealtimeNanosValue
+
+    override fun uptimeMillis(): Long = uptimeMillisValue
+
+    fun advanceBy(duration: Duration) {
+        wallNow = wallNow.plus(duration)
+        elapsedRealtimeMs += duration.toMillis()
+        elapsedRealtimeNanosValue += duration.toNanos()
+        uptimeMillisValue += duration.toMillis()
+    }
+}