Device: Fix call controls setting not applying on AirPods

app/src/main/java/eu/darken/capod/pods/core/apple/aap/protocol/AapCommand.kt

@@ -12,7 +12,19 @@ sealed class AapCommand {
     data class SetNcWithOneAirPod(val enabled: Boolean) : AapCommand()
     data class SetToneVolume(val level: Int) : AapCommand()
     data class SetVolumeSwipeLength(val value: AapSetting.VolumeSwipeLength.Value) : AapCommand()
-    data class SetEndCallMuteMic(val muteMic: AapSetting.EndCallMuteMic.MuteMicMode, val endCall: AapSetting.EndCallMuteMic.EndCallMode) : AapCommand()
+    data class SetEndCallMuteMic(
+        val muteMic: AapSetting.EndCallMuteMic.MuteMicMode,
+        val endCall: AapSetting.EndCallMuteMic.EndCallMode,
+    ) : AapCommand() {
+        init {
+            require(
+                (muteMic == AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS &&
+                    endCall == AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS) ||
+                    (muteMic == AapSetting.EndCallMuteMic.MuteMicMode.DOUBLE_PRESS &&
+                        endCall == AapSetting.EndCallMuteMic.EndCallMode.SINGLE_PRESS)
+            ) { "muteMic and endCall must be complementary press actions" }
+        }
+    }
     data class SetVolumeSwipe(val enabled: Boolean) : AapCommand()
     data class SetPersonalizedVolume(val enabled: Boolean) : AapCommand()
     data class SetAdaptiveAudioNoise(val level: Int) : AapCommand()

app/src/main/java/eu/darken/capod/pods/core/apple/aap/protocol/DefaultAapDeviceProfile.kt

@@ -407,21 +407,41 @@ class DefaultAapDeviceProfile(
         0x00, 0x00, 0x00,
     )
 
-    /** EndCallMuteMic uses a special 2-byte format: [0x24] [0x21] [muteMic] [endCall] [0x00] */
-    private fun buildEndCallMuteMicMessage(muteMic: AapSetting.EndCallMuteMic.MuteMicMode, endCall: AapSetting.EndCallMuteMic.EndCallMode): ByteArray = byteArrayOf(
-        0x04, 0x00, 0x04, 0x00,
-        0x09, 0x00,
-        SETTING_END_CALL_MUTE_MIC.toByte(), 0x21,
-        muteMic.wireValue.toByte(), endCall.wireValue.toByte(),
-        0x00,
-    )
+    /**
+     * EndCallMuteMic write uses compact format [0x24] [0x20] [combined] [0x00] [0x00].
+     * The LibrePods-documented 0x21 "standard" format is silently ignored by real firmware
+     * — no captured session (Pro 1, Pro 2 USB-C, Pro 3) has ever emitted it. Real devices
+     * emit subtype 0x20 or 0x00; writes using 0x20 are accepted and persisted.
+     * Combined-byte mapping mirrors decodeEndCallMuteMic's compact branch.
+     */
+    private fun buildEndCallMuteMicMessage(
+        muteMic: AapSetting.EndCallMuteMic.MuteMicMode,
+        endCall: AapSetting.EndCallMuteMic.EndCallMode,
+    ): ByteArray {
+        val combined = when {
+            muteMic == AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS &&
+                endCall == AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS -> 0x02
+            muteMic == AapSetting.EndCallMuteMic.MuteMicMode.DOUBLE_PRESS &&
+                endCall == AapSetting.EndCallMuteMic.EndCallMode.SINGLE_PRESS -> 0x03
+            else -> error("SetEndCallMuteMic invariant violated (validated by AapCommand.init)")
+        }
+        return byteArrayOf(
+            0x04, 0x00, 0x04, 0x00,
+            0x09, 0x00,
+            SETTING_END_CALL_MUTE_MIC.toByte(), 0x20,
+            combined.toByte(),
+            0x00, 0x00,
+        )
+    }
 
     private fun decodeEndCallMuteMic(payload: ByteArray): Pair<KClass<out AapSetting>, AapSetting>? {
         if (payload.size < 4) return null
         val subType = payload[1].toInt() and 0xFF
         return when (subType) {
             0x21 -> {
-                // Standard format: byte 2 = muteMic, byte 3 = endCall
+                // Legacy doc-sourced format (LibrePods/MagicPodsCore). Never observed in real captures.
+                // Kept for forward-compat: if any unknown firmware emits this, decode still works.
+                // NOTE: writes must use compact 0x20 format — real devices silently ignore 0x21.
                 val muteMic = AapSetting.EndCallMuteMic.MuteMicMode.fromWire(payload[2].toInt() and 0xFF) ?: return null
                 val endCall = AapSetting.EndCallMuteMic.EndCallMode.fromWire(payload[3].toInt() and 0xFF) ?: return null
                 AapSetting.EndCallMuteMic::class to AapSetting.EndCallMuteMic(muteMic, endCall)

app/src/test/java/eu/darken/capod/pods/core/apple/aap/devices/DefaultAapDeviceProfileTest.kt

@@ -7,6 +7,7 @@ import eu.darken.capod.pods.core.apple.aap.protocol.AapMessage
 import eu.darken.capod.pods.core.apple.aap.protocol.AapSetting
 import eu.darken.capod.pods.core.apple.aap.protocol.BaseAapSessionTest
 import eu.darken.capod.pods.core.apple.aap.protocol.DefaultAapDeviceProfile
+import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.matchers.collections.shouldContainExactly
 import io.kotest.matchers.nulls.shouldBeNull
 import io.kotest.matchers.nulls.shouldNotBeNull
@@ -270,12 +271,67 @@ class DefaultAapDeviceProfileTest : BaseAapSessionTest() {
     @Nested
     inner class EndCallMuteMicTests {
         @Test
-        fun `encode single press mute, double press end call`() {
-            val bytes = profile.encodeCommand(AapCommand.SetEndCallMuteMic(AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS, AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS))
-            bytes[6] shouldBe 0x24.toByte()
-            bytes[7] shouldBe 0x21.toByte()
-            bytes[8] shouldBe 0x23.toByte()
-            bytes[9] shouldBe 0x02.toByte()
+        fun `encode single press mute, double press end call (compact 0x20)`() {
+            val bytes = profile.encodeCommand(
+                AapCommand.SetEndCallMuteMic(
+                    AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS,
+                    AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS,
+                )
+            )
+            bytes shouldBe byteArrayOf(
+                0x04, 0x00, 0x04, 0x00,
+                0x09, 0x00,
+                0x24, 0x20,
+                0x02,
+                0x00, 0x00,
+            )
+        }
+
+        @Test
+        fun `encode double press mute, single press end call (compact 0x20)`() {
+            val bytes = profile.encodeCommand(
+                AapCommand.SetEndCallMuteMic(
+                    AapSetting.EndCallMuteMic.MuteMicMode.DOUBLE_PRESS,
+                    AapSetting.EndCallMuteMic.EndCallMode.SINGLE_PRESS,
+                )
+            )
+            bytes shouldBe byteArrayOf(
+                0x04, 0x00, 0x04, 0x00,
+                0x09, 0x00,
+                0x24, 0x20,
+                0x03,
+                0x00, 0x00,
+            )
+        }
+
+        @Test
+        fun `encoded bytes round-trip through decoder`() {
+            listOf(
+                AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS to AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS,
+                AapSetting.EndCallMuteMic.MuteMicMode.DOUBLE_PRESS to AapSetting.EndCallMuteMic.EndCallMode.SINGLE_PRESS,
+            ).forEach { (mute, end) ->
+                val encoded = profile.encodeCommand(AapCommand.SetEndCallMuteMic(mute, end))
+                val message = AapMessage.parse(encoded) ?: error("Failed to parse encoded bytes")
+                val decoded = decodeSetting<AapSetting.EndCallMuteMic>(message)
+                decoded.muteMic shouldBe mute
+                decoded.endCall shouldBe end
+            }
+        }
+
+        @Test
+        fun `SetEndCallMuteMic rejects non-complementary combination`() {
+            shouldThrow<IllegalArgumentException> {
+                AapCommand.SetEndCallMuteMic(
+                    AapSetting.EndCallMuteMic.MuteMicMode.SINGLE_PRESS,
+                    AapSetting.EndCallMuteMic.EndCallMode.SINGLE_PRESS,
+                )
+            }
+            shouldThrow<IllegalArgumentException> {
+                AapCommand.SetEndCallMuteMic(
+                    AapSetting.EndCallMuteMic.MuteMicMode.DOUBLE_PRESS,
+                    AapSetting.EndCallMuteMic.EndCallMode.DOUBLE_PRESS,
+                )
+            }
         }
 
         @Test