o Major refactoring on the BtPromise, mainly internal. Renaming BtPromise to BtSequence and BtSequencer.

28 files changed, 909 insertions, 569 deletions

diff --git a/app/build.gradle b/app/build.gradle
index bea207c..0b6ba45 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,3 +1,5 @@
+// https://github.com/JCAndKSolutions/android-unit-test
+
 def getVersionCode = { ->
     try {
         def stdout = new ByteArrayOutputStream()
@@ -56,7 +58,7 @@ android {
         versionCode getVersionCode()
         versionName getVersionName()
 
-        println("versionCode=$versionCode, versionName=$versionName");
+        return println("versionCode=$versionCode, versionName=$versionName");
     }
     signingConfigs {
         release {
@@ -90,5 +92,22 @@ dependencies {
     }
     compile 'org.sqldroid:sqldroid:1.0.3'
     compile 'org.flywaydb:flyway-core:3.1'
-    //    compile 'net.sourceforge.streamsupport:streamsupport:1.1.2'
+    compile project(':bt')
+}
+
+/*
+apply plugin: 'android-unit-test'
+
+dependencies {
+    compile fileTree(include: ['*.jar'], dir: 'libs')
+    compile('com.crashlytics.sdk.android:crashlytics:2.1.0@aar') {
+        transitive = true;
+    }
+    compile 'org.sqldroid:sqldroid:1.0.3'
+    compile 'org.flywaydb:flyway-core:3.1'
+
+    testCompile 'junit:junit:4.11'
+    testCompile 'org.robolectric:robolectric:2.4'
+    testCompile 'org.easytesting:fest-assert:1.4'
 }
+*/
diff --git a/app/src/main/java/io/trygvis/android/bt/BtDevice.java b/app/src/main/java/io/trygvis/android/bt/BtDevice.java
index b90ac4f..07e4e52 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtDevice.java
+++ b/app/src/main/java/io/trygvis/android/bt/BtDevice.java
@@ -10,10 +10,9 @@ import android.util.Log;
 
 import java.util.Date;
 
-import static io.trygvis.android.bt.BtPromise.BtBluetoothGattCallback;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.detour;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.fail;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.waitForNextEvent;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.detour;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.fail;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.waitForNextEvent;
 
 public class BtDevice<A> implements Comparable<BtDevice> {
     private final static String TAG = BtDevice.class.getSimpleName();
@@ -103,16 +102,16 @@ public class BtDevice<A> implements Comparable<BtDevice> {
      * <p>
      * Services will be discovered.
      */
-    public synchronized void withConnection(BtPromise promise) {
+    public synchronized void withConnection(BtSequence sequence) {
         if (callback != null) {
             throw new RuntimeException("The current callback is not done.");
         }
 
         Log.i(TAG, "withConnection(), address=" + address + ", connected: " + (gatt != null));
 
-        BtPromise newPromise;
+        BtSequence newSequence;
         if (gatt == null) {
-            newPromise = new BtPromise().
+            newSequence = new BtSequence().
                     ignoreFailureForNext().
                     onConnectionStateChange((gatt, status, newState) -> {
                         Log.i(TAG, "defaultConnectCallback: status=" + status + ", newState=" + newState);
@@ -125,7 +124,7 @@ public class BtDevice<A> implements Comparable<BtDevice> {
                         } else {
                             Log.i(TAG, "Could not connect to " + address + ", trying again");
 
-                            return detour(new BtPromise().onConnectionStateChange((gatt2, status2, newState2) -> {
+                            return detour(new BtSequence().onConnectionStateChange((gatt2, status2, newState2) -> {
                                 if (status2 == BluetoothGatt.GATT_SUCCESS && newState2 == BluetoothGatt.STATE_CONNECTED) {
                                     Log.i(TAG, "Connected to " + address + ", discovering services");
                                     return gatt.discoverServices() ? waitForNextEvent() : fail();
@@ -139,25 +138,23 @@ public class BtDevice<A> implements Comparable<BtDevice> {
                     }).
                     onServicesDiscovered(gatt -> {
                         Log.i(TAG, "Services discovered, has " + gatt.getServices().size() + " services");
-                        return detour(promise);
+                        return detour(sequence);
                     });
         } else {
-            newPromise = promise;
+            newSequence = sequence;
         }
 
-        callback = newPromise.
+        BtSequencer sequencer = new BtSequencer(bluetoothDevice.getAddress(), newSequence.
                 onFinally(success -> {
                     Log.i(TAG, "Promise done, device is available again: address=" + address + ", success=" + success);
                     callback = null;
-                }).
-                asCallback(bluetoothDevice.getAddress());
+                }));
+        callback = new BtBluetoothGattCallback(sequencer);
 
         if (gatt == null) {
             gatt = bluetoothDevice.connectGatt(btService, false, wrappingCallback);
         } else {
-            callback.onEvent(BtPromise.EventType.onDirect, "", gatt, null, null,
-                    BluetoothGatt.GATT_SUCCESS,
-                    BluetoothGatt.STATE_CONNECTED);
+            sequencer.onDirect();
         }
     }
 
diff --git a/app/src/main/java/io/trygvis/android/bt/BtPromise.java b/app/src/main/java/io/trygvis/android/bt/BtPromise.java
deleted file mode 100644
index bffdd19..0000000
--- a/app/src/main/java/io/trygvis/android/bt/BtPromise.java
+++ /dev/null
@@ -1,519 +0,0 @@
-package io.trygvis.android.bt;
-
-import android.bluetooth.BluetoothGatt;
-import android.bluetooth.BluetoothGattCallback;
-import android.bluetooth.BluetoothGattCharacteristic;
-import android.bluetooth.BluetoothGattDescriptor;
-import android.util.Log;
-
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
-
-import io.trygvis.android.Consumer;
-import io.trygvis.android.F2;
-import io.trygvis.android.F3;
-import io.trygvis.android.Function;
-
-import static io.trygvis.android.bt.BtPromise.EventType.onCharacteristicChanged;
-import static io.trygvis.android.bt.BtPromise.EventType.onCharacteristicRead;
-import static io.trygvis.android.bt.BtPromise.EventType.onCharacteristicWrite;
-import static io.trygvis.android.bt.BtPromise.EventType.onConnectionStateChange;
-import static io.trygvis.android.bt.BtPromise.EventType.onDescriptorRead;
-import static io.trygvis.android.bt.BtPromise.EventType.onDescriptorWrite;
-import static io.trygvis.android.bt.BtPromise.EventType.onDirect;
-import static io.trygvis.android.bt.BtPromise.EventType.onFinally;
-import static io.trygvis.android.bt.BtPromise.EventType.onReliableWriteCompleted;
-import static io.trygvis.android.bt.BtPromise.EventType.onServicesDiscovered;
-
-public class BtPromise {
-    private final static String TAG = BtPromise.class.getSimpleName();
-    private final List<BtCallback> actionQ = new ArrayList<>();
-    //    private final List<BtCallback> failureQ = new ArrayList<>();
-    private final List<BtCallback> finallyQ = new ArrayList<>();
-
-    private static final PromiseResult waitForNextEvent = new WaitForNextEvent();
-    private static final PromiseResult stop = new Stop();
-    private static final PromiseResult fail = new Fail();
-    private static final PromiseResult continueDirectly = new ContinueDirectly();
-
-    private Boolean stopOnFailure;
-
-    public static class PromiseResult {
-        private PromiseResult() {
-        }
-
-        public static PromiseResult waitForNextEvent() {
-            return waitForNextEvent;
-        }
-
-        public static PromiseResult continueDirectly() {
-            return continueDirectly;
-        }
-
-        public static PromiseResult stop() {
-            return stop;
-        }
-
-        public static PromiseResult fail() {
-            return fail;
-        }
-
-        public static PromiseResult detour(BtPromise promise) {
-            return new Detour(promise);
-        }
-    }
-
-    private static class WaitForNextEvent extends PromiseResult {
-    }
-
-    private static class ContinueDirectly extends PromiseResult {
-    }
-
-    private static class Stop extends PromiseResult {
-    }
-
-    private static class Fail extends PromiseResult {
-    }
-
-    private static class Detour extends PromiseResult {
-        final BtPromise promise;
-
-        private Detour(BtPromise promise) {
-            this.promise = promise;
-        }
-    }
-
-    private boolean stopOnFailure() {
-        if (stopOnFailure != null) {
-            boolean b = stopOnFailure;
-            stopOnFailure = null;
-            return b;
-        }
-        return false;
-    }
-
-    public BtPromise ignoreFailureForNext() {
-        stopOnFailure = true;
-        return this;
-    }
-
-    public synchronized BtPromise onConnectionStateChange(F3<BluetoothGatt, Integer, Integer, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onConnectionStateChange") {
-            @Override
-            public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
-                return callback.apply(gatt, status, newState);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onServicesDiscovered(Function<BluetoothGatt, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onServicesDiscovered") {
-            @Override
-            public PromiseResult onServicesDiscovered(BluetoothGatt gatt) {
-                return callback.apply(gatt);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onCharacteristicRead(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicRead") {
-            @Override
-            public PromiseResult onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
-                return callback.apply(gatt, characteristic);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onCharacteristicWrite(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicWrite") {
-            @Override
-            public PromiseResult onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
-                return callback.apply(gatt, characteristic);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onCharacteristicChanged(F2<BluetoothGatt, BluetoothGattCharacteristic, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onCharacteristicChanged") {
-            @Override
-            public PromiseResult onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
-                return callback.apply(gatt, characteristic);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onDescriptorRead(F2<BluetoothGatt, BluetoothGattDescriptor, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onDescriptorRead") {
-            @Override
-            public PromiseResult onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
-                return callback.apply(gatt, descriptor);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onDescriptorWrite(F2<BluetoothGatt, BluetoothGattDescriptor, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onDescriptorWrite") {
-            @Override
-            public PromiseResult onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
-                return callback.apply(gatt, descriptor);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onReliableWriteCompleted(Function<BluetoothGatt, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onReliableWriteCompleted") {
-            @Override
-            public PromiseResult onReliableWriteCompleted(BluetoothGatt gatt) {
-                return callback.apply(gatt);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onReadRemoteRssi(F2<BluetoothGatt, Integer, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onReadRemoteRssi") {
-            @Override
-            public PromiseResult onReadRemoteRssi(BluetoothGatt gatt, int rssi) {
-                return callback.apply(gatt, rssi);
-            }
-        });
-        return this;
-    }
-
-    public synchronized BtPromise onDirect(Function<BluetoothGatt, PromiseResult> callback) {
-        actionQ.add(new BtCallback(stopOnFailure(), "onDirect") {
-            @Override
-            public PromiseResult onDirect(BluetoothGatt value) {
-                return callback.apply(value);
-            }
-        });
-        return this;
-    }
-
-//    public synchronized BtPromise onFailure(Runnable callback) {
-//        failureQ.add(new BtCallback(stopOnFailure(), "onFailure") {
-//            @Override
-//            public void onFailure() {
-//                callback.run();
-//            }
-//        });
-//        return this;
-//    }
-
-    public synchronized BtPromise onFinally(Consumer<Boolean> callback) {
-        finallyQ.add(new BtCallback(stopOnFailure(), "finally") {
-            @Override
-            public void onFinally(boolean success) {
-                callback.accept(success);
-            }
-        });
-        return this;
-    }
-
-    public BtPromise andThen(BtPromise btPromise) {
-        actionQ.addAll(btPromise.actionQ);
-        finallyQ.addAll(btPromise.finallyQ);
-        return this;
-    }
-
-    public String toString() {
-        StringBuilder s = new StringBuilder("Queue: ");
-
-        Iterator<BtCallback> it = actionQ.iterator();
-
-        int i = 0;
-        while (it.hasNext()) {
-            BtCallback c = it.next();
-            if (i > 0) {
-                s.append(", ");
-            }
-            s.append(c.name);
-            i++;
-        }
-
-        return s.toString();
-    }
-
-    BtBluetoothGattCallback asCallback(String address) {
-        return new BtBluetoothGattCallback(address, actionQ, /*failureQ, */finallyQ);
-    }
-
-    enum EventType {
-        onConnectionStateChange,
-        onServicesDiscovered,
-        onCharacteristicRead,
-        onCharacteristicWrite,
-        onCharacteristicChanged,
-        onDescriptorRead,
-        onDescriptorWrite,
-        onReliableWriteCompleted,
-
-        onReadRemoteRssi,
-
-        onDirect,
-        onFailure,
-        onFinally,
-    }
-
-    private static PromiseResult callCallback(EventType key, BluetoothGatt gatt,
-                                              BluetoothGattCharacteristic characteristic,
-                                              BluetoothGattDescriptor descriptor, int status, int newState,
-                                              Boolean success, BtCallback btCallback) {
-        switch (key) {
-            case onConnectionStateChange:
-                return btCallback.onConnectionStateChange(gatt, status, newState);
-            case onServicesDiscovered:
-                return btCallback.onServicesDiscovered(gatt);
-            case onCharacteristicRead:
-                return btCallback.onCharacteristicRead(gatt, characteristic);
-            case onCharacteristicWrite:
-                return btCallback.onCharacteristicWrite(gatt, characteristic);
-            case onCharacteristicChanged:
-                return btCallback.onCharacteristicChanged(gatt, characteristic);
-            case onDescriptorRead:
-                return btCallback.onDescriptorRead(gatt, descriptor);
-            case onDescriptorWrite:
-                return btCallback.onDescriptorWrite(gatt, descriptor);
-            case onReliableWriteCompleted:
-                return btCallback.onReliableWriteCompleted(gatt);
-
-            case onDirect:
-                return btCallback.onDirect(gatt);
-            case onFailure:
-                btCallback.onFailure();
-                return null;
-            case onFinally:
-                btCallback.onFinally(success);
-                return null;
-            default:
-                Log.w(TAG, "Unknown callback: " + key);
-                return null;
-        }
-    }
-
-    static class BtBluetoothGattCallback extends BluetoothGattCallback {
-
-        private final String address;
-        private List<BtCallback> actionQ;
-        private int currentAction = 0;
-        //        private List<BtCallback> failureQ;
-        private List<BtCallback> finallyQ;
-        private List<String> events = new ArrayList<>();
-
-        private BtBluetoothGattCallback(String address, List<BtCallback> actionQ,
-                                        /*List<BtCallback> failureQ, */List<BtCallback> finallyQ) {
-            this.address = address;
-            this.actionQ = new ArrayList<>(actionQ);
-//            this.failureQ = new ArrayList<>(failureQ);
-            this.finallyQ = new ArrayList<>(finallyQ);
-        }
-
-        void onEvent(EventType key, String values, BluetoothGatt gatt, BluetoothGattCharacteristic characteristic,
-                     BluetoothGattDescriptor descriptor, int status, int newState) {
-            boolean success = status == BluetoothGatt.GATT_SUCCESS;
-            events.add(key + "(" + values + "), success=" + success);
-
-            Log.i(TAG, "event: " + key + "(" + values + "), success=" + success);
-
-            BtCallback btCallback;
-            synchronized (this) {
-                if (!hasNext()) {
-                    Log.d(TAG, "All Bluetooth actions are done, no handler for last event.");
-
-                    doFinally(true);
-                    return;
-                }
-
-                btCallback = actionQ.get(currentAction++);
-
-                if (!success) {
-                    if (btCallback.stopOnFailure) {
-//                        doFailure();
-                        doFinally(false);
-                        return;
-                    } else {
-                        Log.i(TAG, "Last status was a failure, but the callback still want it.");
-                    }
-                }
-
-//                Log.i(TAG, "Graceful sleep" + btCallback.name);
-//                try {
-//                    Thread.sleep(1000);
-//                } catch (InterruptedException e) {
-//                    // ignore
-//                }
-            }
-
-            try {
-                Log.i(TAG, "Executing bt action: " + btCallback.name);
-                PromiseResult result = callCallback(key, gatt, characteristic, descriptor, status, newState, null,
-                        btCallback);
-
-                if (result instanceof Stop) {
-                    Log.i(TAG, "The chain want to stop.");
-                    doFinally(true);
-                    return;
-                }
-
-                if (result instanceof Fail) {
-                    Log.i(TAG, "The chain returned fail().");
-                    doFinally(false);
-                    return;
-                }
-
-                if (result instanceof Detour) {
-                    BtPromise detour = ((Detour) result).promise;
-//                    Log.i(TAG, "Adding detour with " + detour.actionQ.size() + " actions.");
-                    events.add("detour, action size=" + detour.actionQ.size() + ", " +
-//                            "failure size=" + detour.failureQ.size() + ", " +
-                            "finally size=" + detour.finallyQ.size());
-
-                    // The new promise should probably be stacked on top, so that all of its
-                    // finally handlers are executed after the added set concludes and then the
-                    // current stack can continue.
-
-                    actionQ.addAll(currentAction, detour.actionQ);
-//                    failureQ.addAll(detour.failureQ);B
-                    finallyQ.addAll(detour.finallyQ);
-
-                    result = PromiseResult.continueDirectly();
-                }
-
-                if (result instanceof ContinueDirectly) {
-                    onEvent(onDirect, "direct", gatt, null, null, BluetoothGatt.GATT_SUCCESS, 0);
-                    return;
-                }
-
-                if (!hasNext()) {
-                    Log.i(TAG, "The queue is empty");
-                    showEvents();
-                }
-            } catch (NotOverriddenException e) {
-                Log.w(TAG, "Unexpected callback by listener: " + key);
-//                doFailure();
-                doFinally(false);
-            } catch (Exception e) {
-                Log.w(TAG, "Exception in callback", e);
-//                doFailure();
-                doFinally(false);
-            }
-        }
-
-        private boolean hasNext() {
-            return currentAction < actionQ.size();
-        }
-
-//        private void doFailure() {
-//            showEvents();
-//
-//            Log.w(TAG, "Executing " + failureQ.size() + " failure handlers");
-//
-//            for (BtCallback callback : failureQ) {
-//                callCallback(onFailure, null, null, null, 0, 0, callback, null);
-//            }
-//
-//            doFinally();
-//        }
-
-        private void showEvents() {
-            StringBuilder msg = new StringBuilder();
-
-            msg.append("Address: ").append(address).append("\n");
-
-            msg.append("Event handlers: \n");
-            for (BtCallback cb : actionQ) {
-                msg.append("-  ").append(cb.name).append("\n");
-            }
-
-//            msg.append("Failure handlers: \n");
-//            for (BtCallback cb : failureQ) {
-//                msg.append("-  ").append(cb.name).append("\n");
-//            }
-
-            msg.append("Finally handlers: \n");
-            for (BtCallback cb : finallyQ) {
-                msg.append("-  ").append(cb.name).append("\n");
-            }
-
-            msg.append("Events received: \n");
-            for (String event : events) {
-                msg.append("-  ").append(event).append("\n");
-            }
-
-            Log.w(TAG, msg.toString());
-        }
-
-        private void doFinally(boolean success) {
-            showEvents();
-
-            actionQ.clear();
-
-            Log.w(TAG, "Executing " + finallyQ.size() + " finally handlers, success=" + success);
-
-            for (BtCallback callback : finallyQ) {
-                try {
-                    callCallback(onFinally, null, null, null, 0, 0, success, callback);
-                } catch (NotOverriddenException e) {
-                    return;
-                }
-            }
-        }
-
-        // -----------------------------------------------------------------------
-        //
-        // -----------------------------------------------------------------------
-
-        @Override
-        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
-            onEvent(onConnectionStateChange, "status=" + status + ", newState=" + newState, gatt, null, null, status, newState);
-        }
-
-        @Override
-        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
-            onEvent(onServicesDiscovered, "status=" + status, gatt, null, null, status, 9);
-        }
-
-        @Override
-        public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
-            onEvent(onCharacteristicRead, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
-        }
-
-        @Override
-        public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
-            onEvent(onCharacteristicWrite, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
-        }
-
-        @Override
-        public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
-            onEvent(onCharacteristicChanged, "characteristic=" + characteristic.getUuid(), gatt, characteristic, null, BluetoothGatt.GATT_SUCCESS, 0);
-        }
-
-        @Override
-        public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
-            onEvent(onDescriptorRead, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
-        }
-
-        @Override
-        public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
-            onEvent(onDescriptorWrite, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
-        }
-
-        @Override
-        public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
-            onEvent(onReliableWriteCompleted, "status=" + status, gatt, null, null, status, 0);
-        }
-
-        @Override
-        public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
-//                onEvent(onReadRemoteRssi, "status=" + status, gatt, null, null, status, 0);
-        }
-    }
-}
diff --git a/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java b/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
index 3e1c93b..2cf85d9 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/DefaultSoilMoistureService.java
@@ -26,15 +26,16 @@ import java.util.TreeSet;
 import io.trygvis.android.Function;
 import io.trygvis.android.LocalBinder;
 import io.trygvis.android.bt.BtDevice;
-import io.trygvis.android.bt.BtPromise;
+import io.trygvis.android.bt.BtSequence;
 import io.trygvis.android.bt.BtService;
 import io.trygvis.android.bt.DefaultBtService;
 import io.trygvis.bluetooth.TrygvisIoUuids;
 
-import static io.trygvis.android.bt.BtPromise.PromiseResult.continueDirectly;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.detour;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.stop;
-import static io.trygvis.android.bt.BtPromise.PromiseResult.waitForNextEvent;
+import static io.trygvis.android.bt.BtSequence.SequenceResult;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.continueDirectly;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.detour;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.stop;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.waitForNextEvent;
 import static io.trygvis.android.bt.BtService.BtServiceListenerBroadcastReceiver;
 import static io.trygvis.bluetooth.TrygvisIoUuids.CLIENT_CHARACTERISTIC_CONFIG;
 import static io.trygvis.soilmoisture.SmDevice.GetSensorCountRes;
@@ -139,8 +140,8 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
         }
     };
 
-    private BtPromise readAttribute(String value, byte[] req, Function<byte[], BtPromise.PromiseResult> handler) {
-        return new BtPromise().
+    private BtSequence readAttribute(String value, byte[] req, Function<byte[], SequenceResult> handler) {
+        return new BtSequence().
                 onDirect(gatt -> {
                     Log.i(TAG, "Getting attribute: " + value);
 
@@ -158,7 +159,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                 });
     }
 
-    private BtPromise readSensorName(SmDevice device, int index) {
+    private BtSequence readSensorName(SmDevice device, int index) {
         byte[] req = createGetSensorNameReq((byte) index);
 
         return readAttribute("sensor name, index#" + index, req, bytes -> {
@@ -179,7 +180,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
         SmDevice smDevice = btDevice.getTag();
 
         Log.i(TAG, "Probing " + address + ", name=" + btDevice.getName());
-        BtPromise promise = new BtPromise().
+        BtSequence sequence = new BtSequence().
                 onDirect(gatt -> {
                     BluetoothGattService service = gatt.getService(TrygvisIoUuids.Services.SOIL_MOISTURE_SERVICE);
 
@@ -210,7 +211,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                     }
                 });
 
-        BtPromise btPromise = readAttribute("sensor count", createGetSensorCountReq(), bytes -> {
+        BtSequence btSequence = readAttribute("sensor count", createGetSensorCountReq(), bytes -> {
             GetSensorCountRes getSensorCountRes = parseResponse(bytes, GET_SENSOR_COUNT, GetSensorCountRes.class);
 
             int count = getSensorCountRes.count;
@@ -221,9 +222,8 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
 
             return detour(readSensorName(smDevice, 0));
         });
-        promise.andThen(btPromise);
 
-        btDevice.withConnection(promise);
+        btDevice.withConnection(sequence.andThen(btSequence));
     }
 
     private void markDeviceAsNotUseful(SmDevice device) {
@@ -371,7 +371,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
     }
 
     void readCurrentValue(SmSensor sensor) {
-        BtPromise promise = new BtPromise().
+        BtSequence sequence = new BtSequence().
                 onDirect(gatt -> {
                     BluetoothGattService service = gatt.getService(TrygvisIoUuids.Services.SOIL_MOISTURE_SERVICE);
                     BluetoothGattCharacteristic soilMoisture = service.getCharacteristic(TrygvisIoUuids.Characteristics.SOIL_MOISTURE);
@@ -402,7 +402,7 @@ public class DefaultSoilMoistureService extends Service implements SoilMoistureS
                     }
                 });
 
-        sensor.getDevice().getBtDevice().withConnection(promise);
+        sensor.getDevice().getBtDevice().withConnection(sequence);
     }
 
     // -----------------------------------------------------------------------
diff --git a/app/src/main/java/io/trygvis/soilmoisture/SensorActivity.java b/app/src/main/java/io/trygvis/soilmoisture/SensorActivity.java
index 358382c..a5b68d8 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/SensorActivity.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/SensorActivity.java
@@ -128,7 +128,6 @@ public class SensorActivity extends Activity {
     }
 
 
-
     private class SensorSoilMoistureListener extends SoilMoistureListener {
     }
 }
diff --git a/bt/build.gradle b/bt/build.gradle
new file mode 100644
index 0000000..5beefce
--- /dev/null
+++ b/bt/build.gradle
@@ -0,0 +1,46 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath 'me.tatarka:gradle-retrolambda:2.5.0'
+    }
+}
+
+apply plugin: 'java'
+apply plugin: 'idea'
+
+configurations {
+    provided
+}
+
+sourceSets {
+    main.compileClasspath += configurations.provided
+    test.compileClasspath += configurations.provided
+    test.runtimeClasspath += configurations.provided
+}
+
+//sourceCompatibility JavaVersion.VERSION_1_8
+//targetCompatibility JavaVersion.VERSION_1_8
+//sourceCompatibility "1.8"
+//targetCompatibility "1.8"
+
+//compileJava {
+//    sourceCompatibility 1.8
+//    targetCompatibility 1.8
+//}
+
+apply plugin: 'me.tatarka.retrolambda'
+
+dependencies {
+    provided project(':trygvis-io-bt-stubs')
+    testCompile 'junit:junit:4.11'
+    testCompile 'org.easytesting:fest-assert:1.4'
+}
+
+idea {
+    module {
+        scopes.PROVIDED.plus += [configurations.provided] // for Gradle 2.0
+    }
+}
diff --git a/app/src/main/java/io/trygvis/android/Consumer.java b/bt/src/main/java/io/trygvis/android/Consumer.java
index bf8c5e5..bf8c5e5 100644
--- a/app/src/main/java/io/trygvis/android/Consumer.java
+++ b/bt/src/main/java/io/trygvis/android/Consumer.java
diff --git a/app/src/main/java/io/trygvis/android/F2.java b/bt/src/main/java/io/trygvis/android/F2.java
index 1f362cc..1f362cc 100644
--- a/app/src/main/java/io/trygvis/android/F2.java
+++ b/bt/src/main/java/io/trygvis/android/F2.java
diff --git a/app/src/main/java/io/trygvis/android/F3.java b/bt/src/main/java/io/trygvis/android/F3.java
index 30d3adf..30d3adf 100644
--- a/app/src/main/java/io/trygvis/android/F3.java
+++ b/bt/src/main/java/io/trygvis/android/F3.java
diff --git a/app/src/main/java/io/trygvis/android/F4.java b/bt/src/main/java/io/trygvis/android/F4.java
index 5ff50f5..5ff50f5 100644
--- a/app/src/main/java/io/trygvis/android/F4.java
+++ b/bt/src/main/java/io/trygvis/android/F4.java
diff --git a/app/src/main/java/io/trygvis/android/Function.java b/bt/src/main/java/io/trygvis/android/Function.java
index 5e3bb96..5e3bb96 100644
--- a/app/src/main/java/io/trygvis/android/Function.java
+++ b/bt/src/main/java/io/trygvis/android/Function.java
diff --git a/app/src/main/java/io/trygvis/android/Optional.java b/bt/src/main/java/io/trygvis/android/Optional.java
index 616f9a7..616f9a7 100644
--- a/app/src/main/java/io/trygvis/android/Optional.java
+++ b/bt/src/main/java/io/trygvis/android/Optional.java
diff --git a/app/src/main/java/io/trygvis/android/Supplier.java b/bt/src/main/java/io/trygvis/android/Supplier.java
index 222dff2..222dff2 100644
--- a/app/src/main/java/io/trygvis/android/Supplier.java
+++ b/bt/src/main/java/io/trygvis/android/Supplier.java
diff --git a/bt/src/main/java/io/trygvis/android/bt/BtBluetoothGattCallback.java b/bt/src/main/java/io/trygvis/android/bt/BtBluetoothGattCallback.java
new file mode 100644
index 0000000..1f4921f
--- /dev/null
+++ b/bt/src/main/java/io/trygvis/android/bt/BtBluetoothGattCallback.java
@@ -0,0 +1,73 @@
+package io.trygvis.android.bt;
+
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCallback;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattDescriptor;
+
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicChanged;
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicRead;
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicWrite;
+import static io.trygvis.android.bt.BtSequencer.EventType.onConnectionStateChange;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDescriptorRead;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDescriptorWrite;
+import static io.trygvis.android.bt.BtSequencer.EventType.onReliableWriteCompleted;
+import static io.trygvis.android.bt.BtSequencer.EventType.onServicesDiscovered;
+
+public class BtBluetoothGattCallback extends BluetoothGattCallback {
+
+    private final BtSequencer sequencer;
+
+    BtBluetoothGattCallback(BtSequencer sequencer) {
+        this.sequencer = sequencer;
+    }
+
+    // -----------------------------------------------------------------------
+    //
+    // -----------------------------------------------------------------------
+
+    @Override
+    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+        sequencer.onEvent(onConnectionStateChange, "status=" + status + ", newState=" + newState, gatt, null, null, status, newState);
+    }
+
+    @Override
+    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
+        sequencer.onEvent(onServicesDiscovered, "status=" + status, gatt, null, null, status, 9);
+    }
+
+    @Override
+    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+        sequencer.onEvent(onCharacteristicRead, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
+    }
+
+    @Override
+    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+        sequencer.onEvent(onCharacteristicWrite, "status=" + status + ", characteristic=" + characteristic.getUuid(), gatt, characteristic, null, status, 0);
+    }
+
+    @Override
+    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+        sequencer.onEvent(onCharacteristicChanged, "characteristic=" + characteristic.getUuid(), gatt, characteristic, null, BluetoothGatt.GATT_SUCCESS, 0);
+    }
+
+    @Override
+    public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+        sequencer.onEvent(onDescriptorRead, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
+    }
+
+    @Override
+    public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+        sequencer.onEvent(onDescriptorWrite, "status=" + status + ", descriptor=" + descriptor.getUuid(), gatt, null, descriptor, status, 0);
+    }
+
+    @Override
+    public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
+        sequencer.onEvent(onReliableWriteCompleted, "status=" + status, gatt, null, null, status, 0);
+    }
+
+//    @Override
+//    public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
+//        sequencer.onEvent(onReadRemoteRssi, "status=" + status, gatt, null, null, status, 0);
+//    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/io/trygvis/android/bt/BtCallback.java b/bt/src/main/java/io/trygvis/android/bt/BtCallback.java
index 0f7287f..4aa8529 100644
--- a/app/src/main/java/io/trygvis/android/bt/BtCallback.java
+++ b/bt/src/main/java/io/trygvis/android/bt/BtCallback.java
@@ -4,54 +4,55 @@ import android.bluetooth.BluetoothGatt;
 import android.bluetooth.BluetoothGattCharacteristic;
 import android.bluetooth.BluetoothGattDescriptor;
 
-import static io.trygvis.android.bt.BtPromise.PromiseResult;
+import static io.trygvis.android.bt.BtSequence.SequenceResult;
+import static io.trygvis.android.bt.BtSequencer.EventType;
 
 public class BtCallback {
     public final boolean stopOnFailure;
-    public final String name;
+    public final EventType type;
 
-    public BtCallback(boolean stopOnFailure, String name) {
+    public BtCallback(boolean stopOnFailure, EventType type) {
         this.stopOnFailure = stopOnFailure;
-        this.name = name;
+        this.type = type;
     }
 
-    public PromiseResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+    public SequenceResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onServicesDiscovered(BluetoothGatt gatt) {
+    public SequenceResult onServicesDiscovered(BluetoothGatt gatt) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+    public SequenceResult onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+    public SequenceResult onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+    public SequenceResult onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
+    public SequenceResult onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
+    public SequenceResult onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onReliableWriteCompleted(BluetoothGatt gatt) {
+    public SequenceResult onReliableWriteCompleted(BluetoothGatt gatt) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onReadRemoteRssi(BluetoothGatt gatt, int rssi) {
+    public SequenceResult onReadRemoteRssi(BluetoothGatt gatt, int rssi) {
         throw new NotOverriddenException();
     }
 
-    public PromiseResult onDirect(BluetoothGatt value) {
+    public SequenceResult onDirect(BluetoothGatt value) {
         throw new NotOverriddenException();
     }
 
@@ -66,7 +67,7 @@ public class BtCallback {
     @Override
     public String toString() {
         return "BtCallback{" +
-                "name='" + name + '\'' +
+                "type='" + type + '\'' +
                 ", stopOnFailure=" + stopOnFailure +
                 '}';
     }
diff --git a/bt/src/main/java/io/trygvis/android/bt/BtSequence.java b/bt/src/main/java/io/trygvis/android/bt/BtSequence.java
new file mode 100644
index 0000000..be1be4c
--- /dev/null
+++ b/bt/src/main/java/io/trygvis/android/bt/BtSequence.java
@@ -0,0 +1,243 @@
+package io.trygvis.android.bt;
+
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattDescriptor;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ListIterator;
+
+import io.trygvis.android.Consumer;
+import io.trygvis.android.F2;
+import io.trygvis.android.F3;
+import io.trygvis.android.Function;
+import io.trygvis.android.Optional;
+
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicChanged;
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicRead;
+import static io.trygvis.android.bt.BtSequencer.EventType.onCharacteristicWrite;
+import static io.trygvis.android.bt.BtSequencer.EventType.onConnectionStateChange;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDescriptorRead;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDescriptorWrite;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDirect;
+import static io.trygvis.android.bt.BtSequencer.EventType.onFinally;
+import static io.trygvis.android.bt.BtSequencer.EventType.onReadRemoteRssi;
+import static io.trygvis.android.bt.BtSequencer.EventType.onReliableWriteCompleted;
+import static io.trygvis.android.bt.BtSequencer.EventType.onServicesDiscovered;
+import static java.util.Collections.unmodifiableList;
+
+public class BtSequence {
+    private static final SequenceResult waitForNextEvent = new WaitForNextEvent();
+    private static final SequenceResult stop = new Stop();
+    private static final SequenceResult fail = new Fail();
+    private static final SequenceResult continueDirectly = new ContinueDirectly();
+
+    public static class SequenceResult {
+        private SequenceResult() {
+        }
+
+        public static SequenceResult waitForNextEvent() {
+            return waitForNextEvent;
+        }
+
+        public static SequenceResult continueDirectly() {
+            return continueDirectly;
+        }
+
+        public static SequenceResult stop() {
+            return stop;
+        }
+
+        public static SequenceResult fail() {
+            return fail;
+        }
+
+        public static SequenceResult detour(BtSequence sequence) {
+            return new Detour(sequence);
+        }
+    }
+
+    public static class WaitForNextEvent extends SequenceResult {
+    }
+
+    public static class ContinueDirectly extends SequenceResult {
+    }
+
+    public static class Stop extends SequenceResult {
+    }
+
+    public static class Fail extends SequenceResult {
+    }
+
+    public static class Detour extends SequenceResult {
+        final BtSequence sequence;
+
+        private Detour(BtSequence sequence) {
+            this.sequence = sequence;
+        }
+    }
+
+    private final List<BtCallback> actionQ;
+    private final List<BtCallback> finallyQ;
+    private final Optional<BtSequence> next;
+
+    private Boolean stopOnFailure = true;
+
+    public BtSequence() {
+        actionQ = new ArrayList<>();
+        finallyQ = new ArrayList<>();
+        next = Optional.empty();
+    }
+
+    private BtSequence(List<BtCallback> actionQ, List<BtCallback> finallyQ, Optional<BtSequence> next) {
+        this.actionQ = actionQ;
+        this.finallyQ = finallyQ;
+        this.next = next;
+    }
+
+    public BtSequence andThen(BtSequence btSequence) {
+        return new BtSequence(actionQ, finallyQ, Optional.of(btSequence));
+    }
+
+    public ListIterator<BtCallback> actionQ() {
+        return actionQ.listIterator();
+    }
+
+    public List<BtCallback> finallyQ() {
+        return unmodifiableList(finallyQ);
+    }
+
+    public boolean firstIsOnDirect() {
+        return actionQ.size() > 0 && actionQ.get(0).type == onDirect;
+    }
+
+    public Optional<BtSequence> getNext() {
+        return next;
+    }
+
+    public String toString() {
+        return "actionQ=" + actionQ.size() + ", finallyQ=" + finallyQ.size() + ", has next=" + next.isPresent();
+    }
+
+    private BtSequence add(BtCallback callback) {
+        List<BtCallback> actions = new ArrayList<>(this.actionQ);
+        actions.add(callback);
+        return new BtSequence(actions, finallyQ, next);
+    }
+
+    private boolean stopOnFailure() {
+        if (stopOnFailure != null) {
+            boolean b = stopOnFailure;
+            stopOnFailure = null;
+            return b;
+        }
+        return false;
+    }
+
+    public BtSequence ignoreFailureForNext() {
+        stopOnFailure = true;
+        return this;
+    }
+
+    public BtSequence onConnectionStateChange(F3<BluetoothGatt, Integer, Integer, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onConnectionStateChange) {
+            @Override
+            public SequenceResult onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+                return callback.apply(gatt, status, newState);
+            }
+        });
+    }
+
+    public BtSequence onServicesDiscovered(Function<BluetoothGatt, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onServicesDiscovered) {
+            @Override
+            public SequenceResult onServicesDiscovered(BluetoothGatt gatt) {
+                return callback.apply(gatt);
+            }
+        });
+    }
+
+    public BtSequence onCharacteristicRead(F2<BluetoothGatt, BluetoothGattCharacteristic, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onCharacteristicRead) {
+            @Override
+            public SequenceResult onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+                return callback.apply(gatt, characteristic);
+            }
+        });
+    }
+
+    public BtSequence onCharacteristicWrite(F2<BluetoothGatt, BluetoothGattCharacteristic, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onCharacteristicWrite) {
+            @Override
+            public SequenceResult onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+                return callback.apply(gatt, characteristic);
+            }
+        });
+    }
+
+    public BtSequence onCharacteristicChanged(F2<BluetoothGatt, BluetoothGattCharacteristic, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onCharacteristicChanged) {
+            @Override
+            public SequenceResult onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+                return callback.apply(gatt, characteristic);
+            }
+        });
+    }
+
+    public BtSequence onDescriptorRead(F2<BluetoothGatt, BluetoothGattDescriptor, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onDescriptorRead) {
+            @Override
+            public SequenceResult onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
+                return callback.apply(gatt, descriptor);
+            }
+        });
+    }
+
+    public BtSequence onDescriptorWrite(F2<BluetoothGatt, BluetoothGattDescriptor, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onDescriptorWrite) {
+            @Override
+            public SequenceResult onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor) {
+                return callback.apply(gatt, descriptor);
+            }
+        });
+    }
+
+    public BtSequence onReliableWriteCompleted(Function<BluetoothGatt, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onReliableWriteCompleted) {
+            @Override
+            public SequenceResult onReliableWriteCompleted(BluetoothGatt gatt) {
+                return callback.apply(gatt);
+            }
+        });
+    }
+
+    public BtSequence onReadRemoteRssi(F2<BluetoothGatt, Integer, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onReadRemoteRssi) {
+            @Override
+            public SequenceResult onReadRemoteRssi(BluetoothGatt gatt, int rssi) {
+                return callback.apply(gatt, rssi);
+            }
+        });
+    }
+
+    public BtSequence onDirect(Function<BluetoothGatt, SequenceResult> callback) {
+        return add(new BtCallback(stopOnFailure(), onDirect) {
+            @Override
+            public SequenceResult onDirect(BluetoothGatt value) {
+                return callback.apply(value);
+            }
+        });
+    }
+
+    public BtSequence onFinally(Consumer<Boolean> callback) {
+        List<BtCallback> finallyQ = new ArrayList<>(this.finallyQ);
+        finallyQ.add(new BtCallback(stopOnFailure(), onFinally) {
+            @Override
+            public void onFinally(boolean success) {
+                callback.accept(success);
+            }
+        });
+        return new BtSequence(actionQ, finallyQ, next);
+    }
+}
diff --git a/bt/src/main/java/io/trygvis/android/bt/BtSequencer.java b/bt/src/main/java/io/trygvis/android/bt/BtSequencer.java
new file mode 100644
index 0000000..7eecbed
--- /dev/null
+++ b/bt/src/main/java/io/trygvis/android/bt/BtSequencer.java
@@ -0,0 +1,265 @@
+package io.trygvis.android.bt;
+
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.bluetooth.BluetoothGattDescriptor;
+import android.util.Log;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.Iterator;
+import java.util.List;
+
+import static io.trygvis.android.bt.BtSequence.ContinueDirectly;
+import static io.trygvis.android.bt.BtSequence.Detour;
+import static io.trygvis.android.bt.BtSequence.Fail;
+import static io.trygvis.android.bt.BtSequence.SequenceResult;
+import static io.trygvis.android.bt.BtSequence.Stop;
+import static io.trygvis.android.bt.BtSequencer.EventType.onDirect;
+import static io.trygvis.android.bt.BtSequencer.EventType.onFinally;
+
+class BtSequencer {
+    private final static String TAG = BtSequencer.class.getSimpleName();
+
+    enum EventType {
+        onConnectionStateChange,
+        onServicesDiscovered,
+        onCharacteristicRead,
+        onCharacteristicWrite,
+        onCharacteristicChanged,
+        onDescriptorRead,
+        onDescriptorWrite,
+        onReliableWriteCompleted,
+
+        onReadRemoteRssi,
+
+        onDirect,
+        onFailure,
+        onFinally,
+    }
+
+    private final String address;
+    private final Deque<BtSequence> sequences = new ArrayDeque<>();
+    private final Deque<Iterator<BtCallback>> iterators = new ArrayDeque<>();
+
+    private Iterator<BtCallback> callbacks;
+    private BtSequence sequence;
+    private List<String> events = new ArrayList<>();
+
+    private boolean finallyDone;
+
+    BtSequencer(String address, BtSequence sequence) {
+        this.address = address;
+        push(sequence);
+    }
+
+    private void pop() {
+        sequence = sequences.pop();
+        callbacks = iterators.pop();
+    }
+
+    private void push(BtSequence sequence) {
+        if (this.sequence != null) {
+            sequences.push(this.sequence);
+            iterators.push(this.callbacks);
+        }
+
+        this.sequence = sequence;
+        this.callbacks = sequence.actionQ();
+    }
+
+    public void onDirect() {
+        onEvent(onDirect, "initial onDirect", null, null, null, BluetoothGatt.GATT_SUCCESS,
+                BluetoothGatt.STATE_CONNECTED);
+    }
+
+    public synchronized void onEvent(EventType key, String values, BluetoothGatt gatt,
+                                     BluetoothGattCharacteristic characteristic, BluetoothGattDescriptor descriptor,
+                                     int status, int newState) {
+        if (finallyDone) {
+            Log.w(TAG, "Got event after finally has been executed: " + key + "(" + values + ").");
+            return;
+        }
+
+        boolean success = status == BluetoothGatt.GATT_SUCCESS;
+        events.add(key + "(" + values + "), success=" + success);
+
+        Log.i(TAG, "event: " + key + "(" + values + "), success=" + success);
+
+        BtCallback callback;
+        synchronized (this) {
+            if (!callbacks.hasNext() && sequence.getNext().isPresent()) {
+                Log.i(TAG, "Switching to next sequence");
+
+                doFinally(success, sequence);
+
+                sequence = sequence.getNext().get();
+                callbacks = sequence.actionQ();
+            }
+
+            if (!callbacks.hasNext()) {
+                if (!sequences.isEmpty()) {
+                    Log.d(TAG, "Sequence is done, continuing on previous sequence");
+                    doFinally(true, sequence);
+                    pop();
+                } else {
+                    Log.d(TAG, "Sequence is done, no more sequences");
+                    doFinally(true);
+                    return;
+                }
+            }
+
+            callback = callbacks.next();
+
+            if (!success) {
+                if (callback.stopOnFailure) {
+                    doFinally(false);
+                    return;
+                } else {
+                    Log.i(TAG, "Last status was a failure, but the callback still want it.");
+                }
+            }
+        }
+
+        try {
+            Log.i(TAG, "Executing bt action: " + callback.type);
+            SequenceResult result = callCallback(key, gatt, characteristic, descriptor, status, newState, null,
+                    callback);
+
+            if (result instanceof Stop) {
+                Log.i(TAG, "The sequence stopped.");
+                doFinally(true);
+                return;
+            }
+
+            if (result instanceof Fail) {
+                Log.i(TAG, "The sequence failed.");
+                doFinally(false);
+                return;
+            }
+
+            if (result instanceof Detour) {
+                BtSequence detour = ((Detour) result).sequence;
+                Log.i(TAG, "Adding detour: " + detour);
+
+                if (!detour.firstIsOnDirect()) {
+                    throw new IllegalArgumentException("The first handler in a detour must be an onDirect.");
+                }
+
+                events.add("detour, " + detour);
+
+                push(detour);
+                onEvent(onDirect, "direct", gatt, null, null, BluetoothGatt.GATT_SUCCESS, 0);
+                return;
+            }
+
+            if (result instanceof ContinueDirectly) {
+                onEvent(onDirect, "direct", gatt, null, null, BluetoothGatt.GATT_SUCCESS, 0);
+                return;
+            }
+
+            if (!callbacks.hasNext()) {
+                if (!sequences.isEmpty()) {
+                    Log.d(TAG, "Sequence is done, continuing on previous sequence");
+                    doFinally(true, sequence);
+                    pop();
+                } else {
+                    Log.d(TAG, "Sequence is done, no more sequences");
+                    doFinally(true);
+                }
+            }
+        } catch (NotOverriddenException e) {
+            Log.w(TAG, "Unexpected callback by listener: " + key);
+//                doFailure();
+            doFinally(false);
+        } catch (Exception e) {
+            Log.w(TAG, "Exception in callback", e);
+//                doFailure();
+            doFinally(false);
+        }
+    }
+
+    private void doFinally(boolean success) {
+        finallyDone = true;
+        showEvents();
+
+        doFinally(success, sequence);
+
+        while (!sequences.isEmpty()) {
+            doFinally(success, sequences.pop());
+        }
+    }
+
+    private void doFinally(boolean success, BtSequence s) {
+        List<BtCallback> q = s.finallyQ();
+
+        Log.w(TAG, "Executing " + q.size() + " finally handlers, success=" + success);
+        for (BtCallback callback : q) {
+            try {
+                callCallback(onFinally, null, null, null, 0, 0, success, callback);
+            } catch (NotOverriddenException e) {
+                // ignore
+            }
+        }
+    }
+
+    private void showEvents() {
+        StringBuilder msg = new StringBuilder();
+
+        msg.append("Address: ").append(address).append("\n");
+
+//        msg.append("Event handlers: \n");
+//        for (BtCallback cb : actionQ) {
+//            msg.append("-  ").append(cb.name).append("\n");
+//        }
+//
+//        msg.append("Finally handlers: \n");
+//        for (BtCallback cb : finallyQ) {
+//            msg.append("-  ").append(cb.name).append("\n");
+//        }
+
+        msg.append("Events received: \n");
+        for (String event : events) {
+            msg.append("-  ").append(event).append("\n");
+        }
+
+        Log.w(TAG, msg.toString());
+    }
+
+    private static SequenceResult callCallback(EventType key, BluetoothGatt gatt,
+                                               BluetoothGattCharacteristic characteristic,
+                                               BluetoothGattDescriptor descriptor, int status, int newState,
+                                               Boolean success, BtCallback btCallback) {
+        switch (key) {
+            case onConnectionStateChange:
+                return btCallback.onConnectionStateChange(gatt, status, newState);
+            case onServicesDiscovered:
+                return btCallback.onServicesDiscovered(gatt);
+            case onCharacteristicRead:
+                return btCallback.onCharacteristicRead(gatt, characteristic);
+            case onCharacteristicWrite:
+                return btCallback.onCharacteristicWrite(gatt, characteristic);
+            case onCharacteristicChanged:
+                return btCallback.onCharacteristicChanged(gatt, characteristic);
+            case onDescriptorRead:
+                return btCallback.onDescriptorRead(gatt, descriptor);
+            case onDescriptorWrite:
+                return btCallback.onDescriptorWrite(gatt, descriptor);
+            case onReliableWriteCompleted:
+                return btCallback.onReliableWriteCompleted(gatt);
+
+            case onDirect:
+                return btCallback.onDirect(gatt);
+            case onFailure:
+                btCallback.onFailure();
+                return null;
+            case onFinally:
+                btCallback.onFinally(success);
+                return null;
+            default:
+                Log.w(TAG, "Unknown callback: " + key);
+                return null;
+        }
+    }
+}
diff --git a/app/src/main/java/io/trygvis/android/bt/NotOverriddenException.java b/bt/src/main/java/io/trygvis/android/bt/NotOverriddenException.java
index 0f2bb6a..0f2bb6a 100644
--- a/app/src/main/java/io/trygvis/android/bt/NotOverriddenException.java
+++ b/bt/src/main/java/io/trygvis/android/bt/NotOverriddenException.java
diff --git a/bt/src/test/java/io/trygvis/android/bt/BtSequencerTest.java b/bt/src/test/java/io/trygvis/android/bt/BtSequencerTest.java
new file mode 100644
index 0000000..862eda5
--- /dev/null
+++ b/bt/src/test/java/io/trygvis/android/bt/BtSequencerTest.java
@@ -0,0 +1,96 @@
+package io.trygvis.android.bt;
+
+import android.bluetooth.BluetoothGatt;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static io.trygvis.android.bt.BtSequence.SequenceResult.continueDirectly;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.detour;
+import static io.trygvis.android.bt.BtSequence.SequenceResult.stop;
+import static org.fest.assertions.Assertions.assertThat;
+
+@RunWith(JUnit4.class)
+public class BtSequencerTest {
+
+    public static final String ADDRESS = "AA:BB:CC:DD:EE:FF";
+
+    @Test
+    public void eventAndFinally() {
+        List<String> events = new ArrayList<>();
+
+        BtSequence seq = new BtSequence().onConnectionStateChange((gatt, newState, status) -> {
+            events.add("onConnectionStateChange");
+            return stop();
+        }).onFinally(success -> events.add("finally: " + success));
+
+        BtSequencer sequencer = new BtSequencer(ADDRESS, seq);
+
+        sequencer.onEvent(BtSequencer.EventType.onConnectionStateChange, null, null, null, null,
+                BluetoothGatt.GATT_SUCCESS, BluetoothGatt.STATE_CONNECTED);
+
+        assertThat(events).containsSequence(
+                "onConnectionStateChange",
+                "finally: true"
+        );
+    }
+
+    @Test
+    public void detours() {
+        List<String> events = new ArrayList<>();
+
+        BtSequence tour = new BtSequence().onDirect(gatt -> {
+            events.add("tour: onDirect");
+            return stop();
+        }).onFinally(success -> events.add("tour: finally: " + success));
+
+        BtSequence seq = new BtSequence().onConnectionStateChange((gatt, newState, status) -> {
+            events.add("onConnectionStateChange");
+            return detour(tour.andThen(tour));
+        }).onFinally(success -> events.add("finally: " + success));
+
+        BtSequencer sequencer = new BtSequencer(ADDRESS, seq);
+
+        sequencer.onEvent(BtSequencer.EventType.onConnectionStateChange, null, null, null, null,
+                BluetoothGatt.GATT_SUCCESS, BluetoothGatt.STATE_CONNECTED);
+
+        assertThat(events).containsSequence(
+                "onConnectionStateChange",
+                "tour: onDirect",
+                "tour: finally: true",
+                "finally: true"
+        );
+    }
+
+    @Test
+    public void andThen() {
+        List<String> events = new ArrayList<>();
+
+        BtSequence a = new BtSequence().onConnectionStateChange((gatt, newState, status) -> {
+            events.add("a");
+            return continueDirectly();
+        }).onFinally(success -> events.add("a: finally: " + success));
+        BtSequence b = new BtSequence().onDirect(gatt -> {
+            events.add("b");
+            return stop();
+        }).onFinally(success -> events.add("b: finally: " + success));
+
+        BtSequence seq = a.andThen(b);
+
+        BtSequencer sequencer = new BtSequencer(ADDRESS, seq);
+
+        sequencer.onEvent(BtSequencer.EventType.onConnectionStateChange, null, null, null, null,
+                BluetoothGatt.GATT_SUCCESS, BluetoothGatt.STATE_CONNECTED);
+
+        assertThat(events).containsSequence(
+                "a",
+                "a: finally: true",
+                "b",
+                "b: finally: true"
+        );
+    }
+}
diff --git a/build.gradle b/build.gradle
index 234dff0..fae46cd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,7 +5,9 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.0.0-rc4'
+        classpath 'com.android.tools.build:gradle:1.0.1'
+//        classpath 'org.robolectric:robolectric-gradle-plugin:0.14.1'
+        classpath 'com.github.jcandksolutions.gradle:android-unit-test:2.1.1'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/settings.gradle b/settings.gradle
index e7b4def..1d1e858 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1 +1 @@
-include ':app'
+include ':app', ':bt', ':trygvis-io-bt-stubs'
diff --git a/trygvis-io-bt-stubs/build.gradle b/trygvis-io-bt-stubs/build.gradle
new file mode 100644
index 0000000..c152b19
--- /dev/null
+++ b/trygvis-io-bt-stubs/build.gradle
@@ -0,0 +1,5 @@
+apply plugin: 'java'
+
+dependencies {
+    compile fileTree(dir: 'libs', include: ['*.jar'])
+}
\ No newline at end of file
diff --git a/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGatt.java b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGatt.java
new file mode 100644
index 0000000..13b33ed
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGatt.java
@@ -0,0 +1,32 @@
+package android.bluetooth;
+
+import java.util.List;
+import java.util.UUID;
+
+public class BluetoothGatt {
+    public static final int GATT_SUCCESS = 1;
+    public static final int STATE_CONNECTED = 2;
+
+    public boolean discoverServices() {
+        return false;
+    }
+
+    public List getServices() {
+        return null;
+    }
+
+    public BluetoothGattService getService(UUID uuid) {
+        return null;
+    }
+
+    public boolean writeCharacteristic(BluetoothGattCharacteristic characteristic) {
+        return false;
+    }
+
+    public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic, boolean b) {
+    }
+
+    public boolean writeDescriptor(BluetoothGattDescriptor descriptor) {
+        return false;
+    }
+}
diff --git a/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCallback.java b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCallback.java
new file mode 100644
index 0000000..a2a2943
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCallback.java
@@ -0,0 +1,31 @@
+package android.bluetooth;
+
+public class BluetoothGattCallback {
+
+    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
+    }
+
+    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
+    }
+
+    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+    }
+
+    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
+    }
+
+    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
+    }
+
+    public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+    }
+
+    public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
+    }
+
+    public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
+    }
+
+    public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
+    }
+}
diff --git a/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCharacteristic.java b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCharacteristic.java
new file mode 100644
index 0000000..8398b5a
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattCharacteristic.java
@@ -0,0 +1,13 @@
+package android.bluetooth;
+
+import java.util.UUID;
+
+public class BluetoothGattCharacteristic {
+    public UUID getUuid() {
+        return null;
+    }
+
+    public byte[] getValue() {
+        return null;
+    }
+}
diff --git a/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattDescriptor.java b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattDescriptor.java
new file mode 100644
index 0000000..0a86c7e
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattDescriptor.java
@@ -0,0 +1,13 @@
+package android.bluetooth;
+
+import java.util.UUID;
+
+public class BluetoothGattDescriptor {
+    public UUID getUuid() {
+        return null;
+    }
+
+    public BluetoothGattCharacteristic getCharacteristic() {
+        return null;
+    }
+}
diff --git a/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattService.java b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattService.java
new file mode 100644
index 0000000..cd2a57f
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/bluetooth/BluetoothGattService.java
@@ -0,0 +1,4 @@
+package android.bluetooth;
+
+public class BluetoothGattService {
+}
diff --git a/trygvis-io-bt-stubs/src/main/java/android/util/Log.java b/trygvis-io-bt-stubs/src/main/java/android/util/Log.java
new file mode 100644
index 0000000..036ce22
--- /dev/null
+++ b/trygvis-io-bt-stubs/src/main/java/android/util/Log.java
@@ -0,0 +1,20 @@
+package android.util;
+
+public class Log {
+    public static void d(String tag, String s) {
+        System.out.println("d: " + tag + ": " + s);
+    }
+
+    public static void i(String tag, String s) {
+        System.out.println("i: " + tag + ": " + s);
+    }
+
+    public static void w(String tag, String s) {
+        System.out.println("w: " + tag + ": " + s);
+    }
+
+    public static void w(String tag, String s, Exception e) {
+        System.out.println("w: " + tag + ": " + s);
+        e.printStackTrace(System.out);
+    }
+}