/****************************************************************/
/*      Traktor Kontrol S4 MK2 HID controller script v1.00      */
/*      Copyright (C) 2015, the Mixxx Team                      */
/*      but feel free to tweak this to your heart's content!    */
/*      For Mixxx version 2.1                                   */
/****************************************************************/

// TODO:
// * Microphone volume
// * Sampler volume
// * On Air indicator for shoutcast or set recording
// * Loop size readout / selection
// * Find a use for snap / master / other unused buttons?


// ==== Friendly User Configuration ====
// The Remix Slot buttons can have two possible functions:
// 1. Sample launchers: pressing the buttons activates sample players in Mixxx
// 2. Loop Roll: Holding the buttons activates a short loop, and when the button is
//    released playback will resume where the track would have been without the loop.
// To choose sample launching, set the word in quotes below to SAMPLES, all caps.  For
// rolls, change the word to LOOPROLLS (no space).
RemixSlotButtonAction = "SAMPLES";
// The Cue button, when Shift is also held, can have two possible functions:
// 1. "REWIND": seeks to the very start of the track.
// 2. "REVERSEROLL": performs a temporary reverse or "censor" effect, where the track
//    is momentarily played in reverse until the button is released.
ShiftCueButtonAction = "REWIND";


TraktorS4MK2 = new function() {
    this.controller = new HIDController();
    // TODO: Decide if these should be part of this.controller instead.
    this.partial_packet = Object();
    this.divisor_map = Object();
    this.RemixSlotButtonAction = RemixSlotButtonAction;
    this.ShiftCueButtonAction = ShiftCueButtonAction;

    // When true, packets will not be sent to the controller.  Good for doing mass updates.
    this.controller.freeze_lights = false;

    // Active deck switches -- common-hid-packet-parser only has one active deck status per
    // Controller object.
    this.controller.left_deck_C = false;
    this.controller.right_deck_D = false;
    // The controller has a single quantize button, and we remember its state independent of
    // other channels.  (The user may toggle channel quantize in the GUI)
    this.controller.master_quantize = false;
    // Previous values, used for calculating deltas for encoder knobs.
    this.controller.prev_pregain = {
        "[Channel1]": 0,
        "[Channel2]": 0,
        "[Channel3]": 0,
        "[Channel4]": 0
    };
    this.controller.prev_browse = 0;
    this.controller.play_shift_pressed = false;
    this.controller.prev_loopmove = {
        "deck1": 0,
        "deck2": 0
    };
    this.controller.prev_loopsize = {
        "deck1": 0,
        "deck2": 0
    };
    this.controller.shift_pressed = {
        "deck1": false,
        "deck2": false
    };
    this.controller.wheelTouchInertiaTimer = {
        "[Channel1]": 0,
        "[Channel2]": 0,
        "[Channel3]": 0,
        "[Channel4]": 0,
    };
    // Autoslip mode
    this.controller.autoSlipMode = {
        "[Channel1]": false,
        "[Channel2]": false,
        "[Channel3]": false,
        "[Channel4]": false,
    };
    //speed slider range (useful for doing those ridiculous BPM transitions)
    this.controller.tempoRange = {
        "[Channel1]": 0,
        "[Channel2]": 0,
        "[Channel3]": 0,
        "[Channel4]": 0,
    };

    this.controller.tempoRangeList = [8, 16, 24, 50, 90];

    // TODO: convert to Object()s for easier logic.
    this.controller.last_tick_val = [0, 0];
    this.controller.last_tick_time = [0.0, 0.0];
    this.controller.sync_enabled_time = Object();

    // scratch overrides
    // TODO: these can probably be removed, or should be used in my custom scratch code.
    this.controller.scratchintervalsPerRev = 1024;
    this.controller.scratchRPM = 33+1/3;
    this.controller.scratchAlpha = 1.0 / 8;
    this.controller.scratchBeta = this.controller.scratchAlpha / 8;
    this.controller.scratchRampOnEnable = true;
    this.controller.scratchRampOnDisable = true;
};

TraktorS4MK2.registerInputPackets = function() {
    MessageShort = new HIDPacket("shortmessage", 0x01, this.shortMessageCallback);
    MessageLong = new HIDPacket("longmessage", 0x02, this.longMessageCallback);

    // Values in the short message are all buttons, except the jog wheels.
    // An exclamation point indicates a specially-handled function.  Everything else is a standard
    // Mixxx control object name.
    // "deck1" and "deck2" refer to the left deck or right deck, and may be Channel1 or 3 depending
    // on the deck switch state.  These are keywords in the HID library.
    MessageShort.addControl("deck1", "!shift", 0x0D, "B", 0x08);
    MessageShort.addControl("deck1", "!sync_enabled", 0x0D, "B", 0x04);
    MessageShort.addControl("deck1", "!cue_default", 0x0D, "B", 0x02);
    MessageShort.addControl("deck1", "!play", 0x0D, "B", 0x01);
    MessageShort.addControl("deck1", "!hotcue1", 0x0D, "B", 0x80);
    MessageShort.addControl("deck1", "!hotcue2", 0x0D, "B", 0x40);
    MessageShort.addControl("deck1", "!hotcue3", 0x0D, "B", 0x20);
    MessageShort.addControl("deck1", "!hotcue4", 0x0D, "B", 0x10);
    MessageShort.addControl("deck1", "!remix1", 0x0E, "B", 0x80);
    MessageShort.addControl("deck1", "!remix2", 0x0E, "B", 0x40);
    MessageShort.addControl("deck1", "!remix3", 0x0E, "B", 0x20);
    MessageShort.addControl("deck1", "!remix4", 0x0E, "B", 0x10);
    MessageShort.addControl("deck1", "loop_out", 0x0E, "B", 0x08);
    MessageShort.addControl("deck1", "loop_in", 0x0E, "B", 0x04);
    MessageShort.addControl("deck1", "!slip_mode", 0x0E, "B", 0x02);
    MessageShort.addControl("deck1", "!reset_key", 0x0E, "B", 0x01);
    MessageShort.addControl("deck1", "!loop_set", 0x13, "B", 0x02);
    MessageShort.addControl("deck1", "!loop_activate", 0x13, "B", 0x01);
    MessageShort.addControl("deck1", "!jog_touch", 0x11, "B", 0x01);
    MessageShort.addControl("deck1", "!jog_wheel", 0x01, "I");
    MessageShort.addControl("deck1", "!deckswitch", 0x0F, "B", 0x20);
    MessageShort.addControl("deck1", "!load_track", 0x0F, "B", 0x10);
    MessageShort.addControl("deck1", "!FXon", 0x12, "B", 0x80);
    MessageShort.addControl("[EffectRack1_EffectUnit1_Effect1]", "!FXButton", 0x12, "B", 0x40);
    MessageShort.addControl("[EffectRack1_EffectUnit1_Effect2]", "!FXButton", 0x12, "B", 0x20);
    MessageShort.addControl("[EffectRack1_EffectUnit1_Effect3]", "!FXButton", 0x12, "B", 0x10);
    MessageShort.addControl("[EffectRack1_EffectUnit1]", "show_parameters", 0x11, "B", 0x08);

    MessageShort.addControl("deck2", "!shift", 0x0C, "B", 0x08);
    MessageShort.addControl("deck2", "!sync_enabled", 0x0C, "B", 0x04);
    MessageShort.addControl("deck2", "!cue_default", 0x0C, "B", 0x02);
    MessageShort.addControl("deck2", "!play", 0x0C, "B", 0x01);
    MessageShort.addControl("deck2", "!hotcue1", 0x0C, "B", 0x80);
    MessageShort.addControl("deck2", "!hotcue2", 0x0C, "B", 0x40);
    MessageShort.addControl("deck2", "!hotcue3", 0x0C, "B", 0x20);
    MessageShort.addControl("deck2", "!hotcue4", 0x0C, "B", 0x10);
    MessageShort.addControl("deck2", "!remix1", 0x0B, "B", 0x80);
    MessageShort.addControl("deck2", "!remix2", 0x0B, "B", 0x40);
    MessageShort.addControl("deck2", "!remix3", 0x0B, "B", 0x20);
    MessageShort.addControl("deck2", "!remix4", 0x0B, "B", 0x10);
    MessageShort.addControl("deck2", "loop_out", 0x0B, "B", 0x08);
    MessageShort.addControl("deck2", "loop_in", 0x0B, "B", 0x04);
    MessageShort.addControl("deck2", "!slip_mode", 0x0B, "B", 0x02);
    MessageShort.addControl("deck2", "!reset_key", 0x0B, "B", 0x01);
    MessageShort.addControl("deck2", "!loop_set", 0x13, "B", 0x10);
    MessageShort.addControl("deck2", "!loop_activate", 0x13, "B", 0x08);
    MessageShort.addControl("deck2", "!jog_touch", 0x11, "B", 0x02);
    MessageShort.addControl("deck2", "!jog_wheel", 0x05, "I");
    MessageShort.addControl("deck2", "!deckswitch", 0x0A, "B", 0x20);
    MessageShort.addControl("deck2", "!load_track", 0x0A, "B", 0x10);
    MessageShort.addControl("deck2", "!FXon", 0x10, "B", 0x08);
    MessageShort.addControl("[EffectRack1_EffectUnit2_Effect1]", "!FXButton", 0x10, "B", 0x04);
    MessageShort.addControl("[EffectRack1_EffectUnit2_Effect2]", "!FXButton", 0x10, "B", 0x02);
    MessageShort.addControl("[EffectRack1_EffectUnit2_Effect3]", "!FXButton", 0x10, "B", 0x01);
    MessageShort.addControl("[EffectRack1_EffectUnit2]", "show_parameters", 0x11, "B", 0x04);

    MessageShort.addControl("[Channel1]", "pfl", 0x0F, "B", 0x40);
    MessageShort.addControl("[EffectRack1_EffectUnit1]", "group_[Channel1]_enable", 0x12, "B", 0x02);
    MessageShort.addControl("[EffectRack1_EffectUnit2]", "group_[Channel1]_enable", 0x12, "B", 0x01);
    MessageShort.addControl("[Channel1]", "!pregain_reset", 0x11, "B", 0x20);

    MessageShort.addControl("[Channel2]", "pfl", 0x0A, "B", 0x40);
    MessageShort.addControl("[EffectRack1_EffectUnit1]", "group_[Channel2]_enable", 0x10, "B", 0x80);
    MessageShort.addControl("[EffectRack1_EffectUnit2]", "group_[Channel2]_enable", 0x10, "B", 0x40);
    MessageShort.addControl("[Channel2]", "!pregain_reset", 0x11, "B", 0x40);

    MessageShort.addControl("[Channel3]", "pfl", 0x0F, "B", 0x80);
    MessageShort.addControl("[EffectRack1_EffectUnit1]", "group_[Channel3]_enable", 0x12, "B", 0x08);
    MessageShort.addControl("[EffectRack1_EffectUnit2]", "group_[Channel3]_enable", 0x12, "B", 0x04);
    MessageShort.addControl("[Channel3]", "!pregain_reset", 0x11, "B", 0x10);

    MessageShort.addControl("[Channel4]", "pfl", 0x0A, "B", 0x80);
    MessageShort.addControl("[EffectRack1_EffectUnit1]", "group_[Channel4]_enable", 0x10, "B", 0x20);
    MessageShort.addControl("[EffectRack1_EffectUnit2]", "group_[Channel4]_enable", 0x10, "B", 0x10);
    MessageShort.addControl("[Channel4]", "!pregain_reset", 0x11, "B", 0x80);

    MessageShort.addControl("[Library]", "GoToItem",  0x13, "B", 0x04);
    MessageShort.addControl("[PreviewDeck1]", "!previewdeck", 0x0F, "B", 0x01);
    MessageShort.addControl("[Recording]", "toggle_recording", 0x0F, "B", 0x04);
    MessageShort.addControl("[Master]", "!play_shifter", 0x0F, "B", 0x06);


    MessageShort.addControl("[Master]", "!quantize", 0x0A, "B", 0x08);
    MessageShort.addControl("[Master]", "!snap", 0x0A, "B", 0x02);

    MessageShort.setCallback("deck1", "!shift", this.shiftHandler);
    MessageShort.setCallback("deck2", "!shift", this.shiftHandler);
    MessageShort.setCallback("deck1", "!cue_default", this.cueHandler);
    MessageShort.setCallback("deck2", "!cue_default", this.cueHandler);
    MessageShort.setCallback("deck1", "!play", this.playHandler);
    MessageShort.setCallback("deck2", "!play", this.playHandler);
    MessageShort.setCallback("deck1", "!hotcue1", this.hotcueHandler);
    MessageShort.setCallback("deck1", "!hotcue2", this.hotcueHandler);
    MessageShort.setCallback("deck1", "!hotcue3", this.hotcueHandler);
    MessageShort.setCallback("deck1", "!hotcue4", this.hotcueHandler);
    MessageShort.setCallback("deck2", "!hotcue1", this.hotcueHandler);
    MessageShort.setCallback("deck2", "!hotcue2", this.hotcueHandler);
    MessageShort.setCallback("deck2", "!hotcue3", this.hotcueHandler);
    MessageShort.setCallback("deck2", "!hotcue4", this.hotcueHandler);
    MessageShort.setCallback("deck1", "!deckswitch", this.deckSwitchHandler);
    MessageShort.setCallback("deck2", "!deckswitch", this.deckSwitchHandler);
    MessageShort.setCallback("deck1", "!load_track", this.loadTrackHandler);
    MessageShort.setCallback("deck2", "!load_track", this.loadTrackHandler);
    MessageShort.setCallback("deck1", "!sync_enabled", this.syncEnabledHandler);
    MessageShort.setCallback("deck2", "!sync_enabled", this.syncEnabledHandler);
    MessageShort.setCallback("deck1", "!loop_set", this.loopSetHandler);
    MessageShort.setCallback("deck2", "!loop_set", this.loopSetHandler);
    MessageShort.setCallback("deck1", "!loop_activate", this.loopActivateHandler);
    MessageShort.setCallback("deck2", "!loop_activate", this.loopActivateHandler);
    MessageShort.setCallback("deck1", "!jog_touch", this.jogTouchHandler);
    MessageShort.setCallback("deck2", "!jog_touch", this.jogTouchHandler);
    MessageShort.setCallback("deck1", "!jog_wheel", this.jogMoveHandler);
    MessageShort.setCallback("deck2", "!jog_wheel", this.jogMoveHandler);
    MessageShort.setCallback("deck1", "!remix1", this.remixHandler);
    MessageShort.setCallback("deck1", "!remix2", this.remixHandler);
    MessageShort.setCallback("deck1", "!remix3", this.remixHandler);
    MessageShort.setCallback("deck1", "!remix4", this.remixHandler);
    MessageShort.setCallback("deck2", "!remix1", this.remixHandler);
    MessageShort.setCallback("deck2", "!remix2", this.remixHandler);
    MessageShort.setCallback("deck2", "!remix3", this.remixHandler);
    MessageShort.setCallback("deck2", "!remix4", this.remixHandler);
    MessageShort.setCallback("deck1", "!slip_mode", this.slipHandler);
    MessageShort.setCallback("deck2", "!slip_mode", this.slipHandler);
    MessageShort.setCallback("deck1", "!reset_key", this.resetHandler);
    MessageShort.setCallback("deck2", "!reset_key", this.resetHandler);
    MessageShort.setCallback("[Channel1]", "!pregain_reset", this.pregainResetHandler);
    MessageShort.setCallback("[Channel2]", "!pregain_reset", this.pregainResetHandler);
    MessageShort.setCallback("[Channel3]", "!pregain_reset", this.pregainResetHandler);
    MessageShort.setCallback("[Channel4]", "!pregain_reset", this.pregainResetHandler);

    MessageShort.setCallback("[PreviewDeck1]", "!previewdeck", this.previewDeckHandler);
    MessageShort.setCallback("[Master]", "!quantize", this.quantizeHandler);
    MessageShort.setCallback("[Master]", "!snap", this.snapHandler);
    MessageShort.setCallback("[Master]", "!play_shifter", this.playLRButtonHandler);

    MessageShort.setCallback("[EffectRack1_EffectUnit1_Effect1]", "!FXButton", this.FXButtonHandler);
    MessageShort.setCallback("[EffectRack1_EffectUnit1_Effect2]", "!FXButton", this.FXButtonHandler);
    MessageShort.setCallback("[EffectRack1_EffectUnit1_Effect3]", "!FXButton", this.FXButtonHandler);

    MessageShort.setCallback("[EffectRack1_EffectUnit2_Effect1]", "!FXButton", this.FXButtonHandler);
    MessageShort.setCallback("[EffectRack1_EffectUnit2_Effect2]", "!FXButton", this.FXButtonHandler);
    MessageShort.setCallback("[EffectRack1_EffectUnit2_Effect3]", "!FXButton", this.FXButtonHandler);



    // TODO: the rest of the "!" controls.
    this.controller.registerInputPacket(MessageShort);

    // Most items in the long message are controls that go from 0-4096.
    // There are also some 4 bit encoders.
    MessageLong.addControl("deck1", "rate", 0x09, "H");
    MessageLong.addControl("deck2", "rate", 0x0B, "H");
    engine.softTakeover("[Channel1]", "rate", true);
    engine.softTakeover("[Channel2]", "rate", true);
    engine.softTakeover("[Channel3]", "rate", true);
    engine.softTakeover("[Channel4]", "rate", true);
    MessageLong.addControl("deck1", "!loopmove", 0x01, "B", 0x0F, undefined, true);
    MessageLong.addControl("deck2", "!loopmove", 0x02, "B", 0xF0, undefined, true);
    MessageLong.setCallback("deck1", "!loopmove", this.callbackLoopMove);
    MessageLong.setCallback("deck2", "!loopmove", this.callbackLoopMove);
    MessageLong.addControl("deck1", "!loopsize", 0x01, "B", 0xF0, undefined, true);
    MessageLong.addControl("deck2", "!loopsize", 0x03, "B", 0x0F, undefined, true);
    MessageLong.setCallback("deck1", "!loopsize", this.callbackLoopSize);
    MessageLong.setCallback("deck2", "!loopsize", this.callbackLoopSize);

    MessageLong.addControl("[EffectRack1_EffectUnit1]", "mix", 0x3F, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit1_Effect1]", "!FXMeta", 0x41, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit1_Effect2]", "!FXMeta", 0x43, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit1_Effect3]", "!FXMeta", 0x45, "H");

    MessageLong.setCallback("[EffectRack1_EffectUnit1_Effect1]", "!FXMeta", this.FXMetaHandler);
    MessageLong.setCallback("[EffectRack1_EffectUnit1_Effect2]", "!FXMeta", this.FXMetaHandler);
    MessageLong.setCallback("[EffectRack1_EffectUnit1_Effect3]", "!FXMeta", this.FXMetaHandler);

    MessageLong.addControl("[EffectRack1_EffectUnit2]", "mix", 0x47, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit2_Effect1]", "!FXMeta", 0x49, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit2_Effect2]", "!FXMeta", 0x4B, "H");
    MessageLong.addControl("[EffectRack1_EffectUnit2_Effect3]", "!FXMeta", 0x4D, "H");

    MessageLong.setCallback("[EffectRack1_EffectUnit2_Effect1]", "!FXMeta", this.FXMetaHandler);
    MessageLong.setCallback("[EffectRack1_EffectUnit2_Effect2]", "!FXMeta", this.FXMetaHandler);
    MessageLong.setCallback("[EffectRack1_EffectUnit2_Effect3]", "!FXMeta", this.FXMetaHandler);

    MessageLong.addControl("[Channel1]", "volume", 0x37, "H");
    MessageLong.addControl("[QuickEffectRack1_[Channel1]]", "super1", 0x1D, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel1]_Effect1]", "parameter1", 0x1B, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel1]_Effect1]", "parameter2", 0x19, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel1]_Effect1]", "parameter3", 0x17, "H");
    MessageLong.addControl("[Channel1]", "pregain", 0x03, "B", 0xF0, undefined, true);
    MessageLong.setCallback("[Channel1]", "pregain", this.callbackPregain);

    MessageLong.addControl("[Channel2]", "volume", 0x39, "H");
    MessageLong.addControl("[QuickEffectRack1_[Channel2]]", "super1", 0x25, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel2]_Effect1]", "parameter1", 0x23, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel2]_Effect1]", "parameter2", 0x21, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel2]_Effect1]", "parameter3", 0x1F, "H");
    MessageLong.addControl("[Channel2]", "pregain", 0x04, "B", 0x0F, undefined, true);
    MessageLong.setCallback("[Channel2]", "pregain", this.callbackPregain);

    MessageLong.addControl("[Channel3]", "volume", 0x3B, "H");
    MessageLong.addControl("[QuickEffectRack1_[Channel3]]", "super1", 0x2D, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel3]_Effect1]", "parameter1", 0x2B, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel3]_Effect1]", "parameter2", 0x29, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel3]_Effect1]", "parameter3", 0x27, "H");
    MessageLong.addControl("[Channel3]", "pregain", 0x04, "B", 0xF0, undefined, true);
    MessageLong.setCallback("[Channel3]", "pregain", this.callbackPregain);

    MessageLong.addControl("[Channel4]", "volume", 0x3D, "H");
    MessageLong.addControl("[QuickEffectRack1_[Channel4]]", "super1", 0x35, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel4]_Effect1]", "parameter1", 0x33, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel4]_Effect1]", "parameter2", 0x31, "H");
    MessageLong.addControl("[EqualizerRack1_[Channel4]_Effect1]", "parameter3", 0x2F, "H");
    MessageLong.addControl("[Channel4]", "pregain", 0x05, "B", 0x0F, undefined, true);
    MessageLong.setCallback("[Channel4]", "pregain", this.callbackPregain);

    // The physical master button controls the internal sound card volume, so if we hook this
    // up the adjustment is double-applied.
    //MessageLong.addControl("[Master]", "volume", 0x11, "H");
    MessageLong.addControl("[Master]", "crossfader", 0x07, "H");
    MessageLong.addControl("[Master]", "headMix", 0x0D, "H");
    MessageLong.addControl("[Playlist]", "!browse", 0x02, "B", 0x0F, undefined, true);
    MessageLong.setCallback("[Playlist]", "!browse", this.callbackBrowse);

    this.controller.setScaler("volume", this.scalerVolume);
    this.controller.setScaler("headMix", this.scalerSlider);
    this.controller.setScaler("parameter1", this.scalerParameter);
    this.controller.setScaler("parameter2", this.scalerParameter);
    this.controller.setScaler("parameter3", this.scalerParameter);
    this.controller.setScaler("super1", this.scalerParameter);
    this.controller.setScaler("crossfader", this.scalerSlider);
    this.controller.setScaler("rate", this.scalerSlider);
    this.controller.setScaler("mix", this.scalerParameter);
    this.controller.registerInputPacket(MessageLong);
};

TraktorS4MK2.registerOutputPackets = function() {
    Output1 = new HIDPacket("output1", 0x80);
    Output2 = new HIDPacket("output2", 0x81);
    Output3 = new HIDPacket("output3", 0x82);

    Output1.addOutput("[Channel1]", "track_samples", 0x10, "B");
    Output1.addOutput("[Channel2]", "track_samples", 0x18, "B");
    Output1.addOutput("[Channel3]", "track_samples", 0x08, "B");
    Output1.addOutput("[Channel4]", "track_samples", 0x20, "B");

    var VuOffsets = {
        "[Channel1]": 0x09,
        "[Channel2]": 0x11,
        "[Channel3]": 0x01,
        "[Channel4]": 0x19
    };
    for (ch in VuOffsets) {
        for (i = 0; i < 0x06; i++) {
            Output1.addOutput(ch, "!" + "VuMeter" + i, VuOffsets[ch] + i, "B");
        }
    }



    Output1.addOutput("[Channel1]", "peak_indicator", 0x0F, "B");
    Output1.addOutput("[Channel2]", "peak_indicator", 0x17, "B");
    Output1.addOutput("[Channel3]", "peak_indicator", 0x07, "B");
    Output1.addOutput("[Channel4]", "peak_indicator", 0x1F, "B");

    Output1.addOutput("[Master]", "!usblight", 0x2A, "B");
    Output1.addOutput("[Master]", "!quantize", 0x31, "B");
    Output1.addOutput("[InternalClock]", "sync_leader", 0x30, "B");
    Output1.addOutput("[Recording]", "status", 0x34, "B");

    this.controller.registerOutputPacket(Output1);

    Output2.addOutput("deck1", "!shift", 0x1D, "B");
    Output2.addOutput("deck1", "sync_enabled", 0x1E, "B");
    Output2.addOutput("deck1", "cue_indicator", 0x1F, "B");
    Output2.addOutput("deck1", "play_indicator", 0x20, "B");
    Output2.addOutput("deck1", "hotcue_1_enabled", 0x01, "B");
    Output2.addOutput("deck1", "!hotcue_1_enabled_G", 0x02, "B");
    Output2.addOutput("deck1", "!hotcue_1_enabled_B", 0x03, "B");
    Output2.addOutput("deck1", "hotcue_2_enabled", 0x04, "B");
    Output2.addOutput("deck1", "!hotcue_2_enabled_G", 0x05, "B");
    Output2.addOutput("deck1", "!hotcue_2_enabled_B", 0x06, "B");
    Output2.addOutput("deck1", "hotcue_3_enabled", 0x07, "B");
    Output2.addOutput("deck1", "!hotcue_3_enabled_G", 0x08, "B");
    Output2.addOutput("deck1", "!hotcue_3_enabled_B", 0x09, "B");
    Output2.addOutput("deck1", "hotcue_4_enabled", 0x0A, "B");
    Output2.addOutput("deck1", "!hotcue_4_enabled_G", 0x0B, "B");
    Output2.addOutput("deck1", "!hotcue_4_enabled_B", 0x0C, "B");
    Output2.addOutput("deck1", "loop_in", 0x29, "B");
    Output2.addOutput("deck1", "loop_out", 0x2A, "B");
    Output2.addOutput("deck1", "keylock", 0x2F, "B");
    Output2.addOutput("deck1", "slip_enabled", 0x39, "B");
    Output2.addOutput("deck1", "!on_air", 0x2D, "B");
    Output2.addOutput("deck1", "!remix", 0x30, "B");
    Output2.addOutput("deck2", "!shift", 0x25, "B");
    Output2.addOutput("deck2", "sync_enabled", 0x26, "B");
    Output2.addOutput("deck2", "cue_indicator", 0x27, "B");
    Output2.addOutput("deck2", "play_indicator", 0x28, "B");
    Output2.addOutput("deck2", "hotcue_1_enabled", 0x0D, "B");
    Output2.addOutput("deck2", "!hotcue_1_enabled_G", 0x0E, "B");
    Output2.addOutput("deck2", "!hotcue_1_enabled_B", 0x0F, "B");
    Output2.addOutput("deck2", "hotcue_2_enabled", 0x10, "B");
    Output2.addOutput("deck2", "!hotcue_2_enabled_G", 0x11, "B");
    Output2.addOutput("deck2", "!hotcue_2_enabled_B", 0x12, "B");
    Output2.addOutput("deck2", "hotcue_3_enabled", 0x13, "B");
    Output2.addOutput("deck2", "!hotcue_3_enabled_G", 0x14, "B");
    Output2.addOutput("deck2", "!hotcue_3_enabled_B", 0x15, "B");
    Output2.addOutput("deck2", "hotcue_4_enabled", 0x16, "B");
    Output2.addOutput("deck2", "!hotcue_4_enabled_G", 0x17, "B");
    Output2.addOutput("deck2", "!hotcue_4_enabled_B", 0x18, "B");
    Output2.addOutput("deck2", "loop_in", 0x2B, "B");
    Output2.addOutput("deck2", "loop_out", 0x2C, "B");
    Output2.addOutput("deck2", "keylock", 0x35, "B");
    Output2.addOutput("deck2", "slip_enabled", 0x3B, "B");
    Output2.addOutput("deck2", "!on_air", 0x33, "B");
    Output2.addOutput("deck2", "!remix", 0x36, "B");
    Output2.addOutput("[Channel1]", "!deck_A", 0x2E, "B");
    Output2.addOutput("[Channel2]", "!deck_B", 0x34, "B");
    Output2.addOutput("[Channel3]", "!deck_C", 0x31, "B");
    Output2.addOutput("[Channel4]", "!deck_D", 0x37, "B");

    Output2.addOutput("[PreviewDeck1]", "play_indicator", 0x3D, "B");


    // Note: this logic means remix button actions are not switchable without reloading the script.
    // Once we have support for controller preferences, this can be changed.
    if (TraktorS4MK2.RemixSlotButtonAction === "SAMPLES") {
        Output2.addOutput("[Sampler1]", "play_indicator", 0x19, "B");
        Output2.addOutput("[Sampler2]", "play_indicator", 0x1A, "B");
        Output2.addOutput("[Sampler3]", "play_indicator", 0x1B, "B");
        Output2.addOutput("[Sampler4]", "play_indicator", 0x1C, "B");
        Output2.addOutput("[Sampler5]", "play_indicator", 0x21, "B");
        Output2.addOutput("[Sampler6]", "play_indicator", 0x22, "B");
        Output2.addOutput("[Sampler7]", "play_indicator", 0x23, "B");
        Output2.addOutput("[Sampler8]", "play_indicator", 0x24, "B");
    } else if (TraktorS4MK2.RemixSlotButtonAction === "LOOPROLLS") {
        Output2.addOutput("deck1", "beatlooproll_0.125_activate", 0x19, "B");
        Output2.addOutput("deck1", "beatlooproll_0.25_activate", 0x1A, "B");
        Output2.addOutput("deck1", "beatlooproll_0.5_activate", 0x1B, "B");
        Output2.addOutput("deck1", "beatlooproll_1_activate", 0x1C, "B");
        Output2.addOutput("deck2", "beatlooproll_0.125_activate", 0x21, "B");
        Output2.addOutput("deck2", "beatlooproll_0.25_activate", 0x22, "B");
        Output2.addOutput("deck2", "beatlooproll_0.5_activate", 0x23, "B");
        Output2.addOutput("deck2", "beatlooproll_1_activate", 0x24, "B");
    }

    this.controller.registerOutputPacket(Output2);

    Output3.addOutput("[Channel3]", "pfl", 0x17, "B");
    Output3.addOutput("[Channel1]", "pfl", 0x18, "B");
    Output3.addOutput("[Channel2]", "pfl", 0x19, "B");
    Output3.addOutput("[Channel4]", "pfl", 0x1A, "B");

    Output3.addOutput("[Main]", "peak_indicator_left", 0x3B, "B");
    Output3.addOutput("[Main]", "peak_indicator_right", 0x3C, "B");

    Output3.addOutput("deck1", "!deckLight", 0x13, "B");
    Output3.addOutput("deck1", "LoadSelectedTrack", 0x14, "B");

    Output3.addOutput("deck2", "!deckLight", 0x16, "B");
    Output3.addOutput("deck2", "LoadSelectedTrack", 0x15, "B");

    Output3.addOutput("[EffectRack1_EffectUnit1]", "group_[Channel3]_enable", 0x05, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2]", "group_[Channel3]_enable", 0x06, "B");
    Output3.addOutput("[EffectRack1_EffectUnit1]", "group_[Channel1]_enable", 0x07, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2]", "group_[Channel1]_enable", 0x08, "B");
    Output3.addOutput("[EffectRack1_EffectUnit1]", "group_[Channel2]_enable", 0x09, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2]", "group_[Channel2]_enable", 0x0A, "B");
    Output3.addOutput("[EffectRack1_EffectUnit1]", "group_[Channel4]_enable", 0x0B, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2]", "group_[Channel4]_enable", 0x0C, "B");

    Output3.addOutput("[EffectRack1_EffectUnit1_Effect1]", "enabled", 0x02, "B");
    Output3.addOutput("[EffectRack1_EffectUnit1_Effect2]", "enabled", 0x03, "B");
    Output3.addOutput("[EffectRack1_EffectUnit1_Effect3]", "enabled", 0x04, "B");

    Output3.addOutput("[EffectRack1_EffectUnit2_Effect1]", "enabled", 0x0E, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2_Effect2]", "enabled", 0x0F, "B");
    Output3.addOutput("[EffectRack1_EffectUnit2_Effect3]", "enabled", 0x10, "B");

    Output3.addOutput("[EffectRack1_EffectUnit1]", "show_parameters", 0x11, "B");

    Output3.addOutput("[EffectRack1_EffectUnit2]", "show_parameters", 0x12, "B");


    for (i=0; i < 16; i++) {
        Output3.addOutput("deck1", "!loopSize"+i, 0x1B+i, "B");
        Output3.addOutput("deck2", "!loopSize"+i, 0x2B+i, "B");
    }

    this.controller.registerOutputPacket(Output3);

    // Link up control objects to their outputs
    TraktorS4MK2.linkDeckOutputs("sync_enabled", TraktorS4MK2.outputCallback);
    TraktorS4MK2.linkDeckOutputs("cue_indicator", TraktorS4MK2.outputCallback);
    TraktorS4MK2.linkDeckOutputs("play_indicator", TraktorS4MK2.outputCallback);
    TraktorS4MK2.linkDeckOutputs("hotcue_1_enabled", TraktorS4MK2.outputCueCallback);
    TraktorS4MK2.linkDeckOutputs("hotcue_2_enabled", TraktorS4MK2.outputCueCallback);
    TraktorS4MK2.linkDeckOutputs("hotcue_3_enabled", TraktorS4MK2.outputCueCallback);
    TraktorS4MK2.linkDeckOutputs("hotcue_4_enabled", TraktorS4MK2.outputCueCallback);
    TraktorS4MK2.linkDeckOutputs("loop_in", TraktorS4MK2.outputCallbackLoop);
    TraktorS4MK2.linkDeckOutputs("loop_out", TraktorS4MK2.outputCallbackLoop);
    TraktorS4MK2.linkDeckOutputs("keylock", TraktorS4MK2.outputCallbackDark);
    TraktorS4MK2.linkDeckOutputs("LoadSelectedTrack", TraktorS4MK2.outputCallback);
    TraktorS4MK2.linkDeckOutputs("slip_enabled", TraktorS4MK2.outputCallback);
    TraktorS4MK2.linkChannelOutput("[Channel1]", "pfl", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel2]", "pfl", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel3]", "pfl", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel4]", "pfl", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel1]", "track_samples", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel2]", "track_samples", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel3]", "track_samples", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel4]", "track_samples", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[Channel1]", "peak_indicator", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[Channel2]", "peak_indicator", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[Channel3]", "peak_indicator", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[Channel4]", "peak_indicator", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[Main]", "peak_indicator_left", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[Main]", "peak_indicator_right", TraktorS4MK2.outputChannelCallbackDark);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1]", "group_[Channel3]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2]", "group_[Channel3]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1]", "group_[Channel1]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2]", "group_[Channel1]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1]", "group_[Channel2]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2]", "group_[Channel2]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1]", "group_[Channel4]_enable", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2]", "group_[Channel4]_enable", TraktorS4MK2.outputChannelCallback);

    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1]", "show_parameters", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2]", "show_parameters", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1_Effect1]", "enabled", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1_Effect2]", "enabled", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit1_Effect3]", "enabled", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2_Effect1]", "enabled", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2_Effect2]", "enabled", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[EffectRack1_EffectUnit2_Effect3]", "enabled", TraktorS4MK2.outputChannelCallback);

    TraktorS4MK2.linkChannelOutput("[PreviewDeck1]", "play_indicator", TraktorS4MK2.outputChannelCallback);
    TraktorS4MK2.linkChannelOutput("[InternalClock]", "sync_leader", TraktorS4MK2.outputChannelCallback);

    if (TraktorS4MK2.RemixSlotButtonAction === "SAMPLES") {
        TraktorS4MK2.linkChannelOutput("[Sampler1]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler2]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler3]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler4]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler5]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler6]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler7]", "play_indicator", TraktorS4MK2.outputChannelCallback);
        TraktorS4MK2.linkChannelOutput("[Sampler8]", "play_indicator", TraktorS4MK2.outputChannelCallback);
    } else if (TraktorS4MK2.RemixSlotButtonAction === "LOOPROLLS") {
        TraktorS4MK2.linkDeckOutputs("beatlooproll_0.125_activate", TraktorS4MK2.outputCallback);
        TraktorS4MK2.linkDeckOutputs("beatlooproll_0.25_activate", TraktorS4MK2.outputCallback);
        TraktorS4MK2.linkDeckOutputs("beatlooproll_0.5_activate", TraktorS4MK2.outputCallback);
        TraktorS4MK2.linkDeckOutputs("beatlooproll_1_activate", TraktorS4MK2.outputCallback);
    }

    engine.connectControl("[Recording]", "status", "TraktorS4MK2.onRecordingChanged");

    // VU meters get special attention
    engine.connectControl("[Channel1]", "vu_meter", "TraktorS4MK2.onVuMeterChanged");
    engine.connectControl("[Channel2]", "vu_meter", "TraktorS4MK2.onVuMeterChanged");
    engine.connectControl("[Channel3]", "vu_meter", "TraktorS4MK2.onVuMeterChanged");
    engine.connectControl("[Channel4]", "vu_meter", "TraktorS4MK2.onVuMeterChanged");

    engine.connectControl("[Channel1]", "loop_enabled", "TraktorS4MK2.onLoopEnabledChanged");
    engine.connectControl("[Channel2]", "loop_enabled", "TraktorS4MK2.onLoopEnabledChanged");
    engine.connectControl("[Channel3]", "loop_enabled", "TraktorS4MK2.onLoopEnabledChanged");
    engine.connectControl("[Channel4]", "loop_enabled", "TraktorS4MK2.onLoopEnabledChanged");

    engine.connectControl("[Channel1]", "beatloop_size", "TraktorS4MK2.onLoopSizeChanged");
    engine.connectControl("[Channel2]", "beatloop_size", "TraktorS4MK2.onLoopSizeChanged");
    engine.connectControl("[Channel3]", "beatloop_size", "TraktorS4MK2.onLoopSizeChanged");
    engine.connectControl("[Channel4]", "beatloop_size", "TraktorS4MK2.onLoopSizeChanged");

};

TraktorS4MK2.linkDeckOutputs = function(key, callback) {
    // Linking outputs is a little tricky because the library doesn't quite do what I want.  But this
    // method works.
    TraktorS4MK2.controller.linkOutput("deck1", key, "[Channel1]", key, callback);
    engine.connectControl("[Channel3]", key, callback);
    TraktorS4MK2.controller.linkOutput("deck2", key, "[Channel2]", key, callback);
    engine.connectControl("[Channel4]", key, callback);
};

TraktorS4MK2.linkChannelOutput = function(group, key, callback) {
    TraktorS4MK2.controller.linkOutput(group, key, group, key, callback);
};

TraktorS4MK2.lightGroup = function(packet, output_group_name, co_group_name) {
    var group_ob = packet.groups[output_group_name];
    for (var field_name in group_ob) {
        field = group_ob[field_name];
        if (field.name[0] === "!") {
            continue;
        }
        if (field.mapped_callback) {
            var value = engine.getValue(co_group_name, field.name);
            field.mapped_callback(value, co_group_name, field.name);
        }
        // No callback, no light!
    }
};

TraktorS4MK2.lightDeck = function(group) {
    // Freeze the lights while we do this update so we don't spam HID.
    this.controller.freeze_lights = true;
    for (var packet_name in this.controller.OutputPackets) {
        packet = this.controller.OutputPackets[packet_name];
        var deck_group_name = "deck1";
        if (group === "[Channel2]" || group === "[Channel4]") {
            deck_group_name = "deck2";
        }

        TraktorS4MK2.lightGroup(packet, deck_group_name, group);
        TraktorS4MK2.lightGroup(packet, group, group);
        // Shift is a weird key because there's no CO that it is actually associated with.
        TraktorS4MK2.outputCallback(0, group, "!shift");
    }

    // FX buttons
    var packet = this.controller.OutputPackets["output3"];
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit1]", "[EffectRack1_EffectUnit1]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit2]", "[EffectRack1_EffectUnit2]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit1_Effect1]", "[EffectRack1_EffectUnit1_Effect1]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit1_Effect2]", "[EffectRack1_EffectUnit1_Effect2]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit1_Effect3]", "[EffectRack1_EffectUnit1_Effect3]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit2_Effect1]", "[EffectRack1_EffectUnit2_Effect1]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit2_Effect2]", "[EffectRack1_EffectUnit2_Effect2]");
    TraktorS4MK2.lightGroup(packet, "[EffectRack1_EffectUnit2_Effect3]", "[EffectRack1_EffectUnit2_Effect3]");

    // Selected deck lights
    if (group === "[Channel1]") {
        TraktorS4MK2.controller.setOutput("[Channel1]", "!deck_A", 0x7F, false);
        TraktorS4MK2.controller.setOutput("[Channel3]", "!deck_C", 0x00, false);
        TraktorS4MK2.controller.setOutput("deck1", "!deckLight", 0x05, false);
        TraktorS4MK2.loopSizeSet(group);
        TraktorS4MK2.lightSlipAuto(group);
    } else if (group === "[Channel2]") {
        TraktorS4MK2.controller.setOutput("[Channel2]", "!deck_B", 0x7F, false);
        TraktorS4MK2.controller.setOutput("[Channel4]", "!deck_D", 0x00, false);
        TraktorS4MK2.controller.setOutput("deck2", "!deckLight", 0x05, false);
        TraktorS4MK2.loopSizeSet(group);
        TraktorS4MK2.lightSlipAuto(group);
    } else if (group === "[Channel3]") {
        TraktorS4MK2.controller.setOutput("[Channel3]", "!deck_C", 0x7F, false);
        TraktorS4MK2.controller.setOutput("[Channel1]", "!deck_A", 0x00, false);
        TraktorS4MK2.controller.setOutput("deck1", "!deckLight", 0x7F, false);
        TraktorS4MK2.loopSizeSet(group);
        TraktorS4MK2.lightSlipAuto(group);
    } else if (group === "[Channel4]") {
        TraktorS4MK2.controller.setOutput("[Channel4]", "!deck_D", 0x7F, false);
        TraktorS4MK2.controller.setOutput("[Channel2]", "!deck_B", 0x00, false);
        TraktorS4MK2.controller.setOutput("deck2", "!deckLight", 0x7F, false);
        TraktorS4MK2.loopSizeSet(group);
        TraktorS4MK2.lightSlipAuto(group);
    }

    this.controller.freeze_lights = false;
    // And now send them all.
    for (packet_name in this.controller.OutputPackets) {
        var packet_ob = this.controller.OutputPackets[packet_name];
        packet_ob.send();
    }
};

TraktorS4MK2.pointlessLightShow = function() {
    var packets = [Object(), Object(), Object()];

    packets[0].length = 52;
    packets[1].length = 62;
    packets[2].length = 60;

    // Fade up all lights evenly from 0 to 0x7F
    for (k = 0; k < 0x7F; k+=0x05) {
        for (var i = 0; i < packets.length; i++) {
            for (j = 0; j < packets[i].length; j++) {
                packets[i][j] = k;
            }
        }

        controller.send(packets[0], packets[0].length, 0x80);
        controller.send(packets[1], packets[1].length, 0x81);
        controller.send(packets[2], packets[2].length, 0x82);
        // "sleep"
        var then = Date.now();
        while (true) {
            var now = Date.now();
            if (now - then > 25) {
                break;
            }
        }
    }
};

TraktorS4MK2.init = function(id) {
    if (engine.getValue("[App]", "num_samplers") < 16) {
        engine.setValue("[App]", "num_samplers", 16);
    }
    TraktorS4MK2.pointlessLightShow();
    TraktorS4MK2.registerInputPackets();
    TraktorS4MK2.registerOutputPackets();

    // Initialize master quantize based on the state of Channel1.  It's the best we can do for now
    // until we have controller preferences.
    TraktorS4MK2.master_quantize = engine.getValue("[Channel1]", "quantize");
    engine.setValue("[Channel1]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel2]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel3]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel4]", "quantize", TraktorS4MK2.master_quantize);
    TraktorS4MK2.controller.setOutput("[Master]", "!quantize", 0x7F * TraktorS4MK2.master_quantize, true);

    TraktorS4MK2.controller.setOutput("[Master]", "!usblight", 0x7F, true);

    TraktorS4MK2.outputChannelCallback(engine.getValue("[InternalClock]", "sync_leader"), "[InternalClock]", "sync_leader");
    TraktorS4MK2.outputChannelCallback(engine.getValue("[Recording]", "status"), "[Recording]", "status");
    TraktorS4MK2.controller.setOutput("deck1", "!on_air", engine.getValue("[Recording]", "status")*0x7F);
    TraktorS4MK2.controller.setOutput("deck2", "!on_air", engine.getValue("[Recording]", "status")*0x7F);
    TraktorS4MK2.lightDeck("[PreviewDeck1]");
    // Light 3 and 4 first so we get the mixer lights on, then do 1 and 2 since those are active
    // on startup.
    TraktorS4MK2.lightDeck("[Channel3]");
    TraktorS4MK2.lightDeck("[Channel4]");
    TraktorS4MK2.lightDeck("[Channel1]");
    TraktorS4MK2.lightDeck("[Channel2]");

    HIDDebug("TraktorS4MK2: done init");
};

TraktorS4MK2.debugLights = function() {
    // Call this if you want to just send raw packets to the controller (good for figuring out what
    // bytes do what).
    //var data_strings = ["80 00 00 00 00 00 00 00 0A 00 00 00 00 00 00 00 0A 00 00 00 00 00 00 00 0A 00 00 00 00 00 00 00 0A 0A 0A 0A 0A 0A 0A 0A 0A 00 7F 00 00 00 00 0A 0A 0A 0A 0A 0A",
    //                    "81 0B 03 00 0B 03 00 0B 03 00 0B 03 00 0B 03 00 0B 03 00 0B 03 00 0B 03 00 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 7F 0A 0A 0A 0A 0A 7F 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A",
    //                    "82 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 0A 00 00 7F 7F 7F 7F 7F 7F 00 00 7F 7F 7F 7F 7F 00 00 00 7F 7F 7F 7F 7F 7F 00 00 7F 7F 7F 7F 7F 00 00 00"];
    //                   00 01 02 03  04 05 06 07  08 09 0A 0B  0C 0D 0E 0F
    var data_strings = [
        "00 00 00  00 00 00 00  0A 00 00 00  00 00 00 00  \n" +
        "0A 00 00 00  00 00 00 00  0A 00 00 00  00 00 00 00  \n" +
        "0A 0A 0A 0A  0A 0A 0A 0A  0A 00 7F 00  00 00 00 0A  \n" +
        "0A 0A 0A 0A  0A",
        "00 00 7F  7F 03 7F 0B  03 7F 0B 03  7F 0B 03 7F  \n" +
        "0B 03 7F 0B  03 00 7f 03  7F 0A 0A 0A  00 7f 0A 0A  \n" +
        "00 7f 0A 0A  0A 0A 0A 0A  7F 0A 0a 0A  0a 0a 7f 0a  \n" +
        "0a 0a 0a 0a  7F 0A 0A 0A  0a 0a 0a 0a  0a 0a 0a",
        "0a 0A 0A  0a 0a 0a 0A  0A 0A 0A 0A  0a 0a 0A 0A  \n" +
        "0a 0a 0a 0a  0a 0a 0a 0a  0A 0A 0a 0a  00 00 00 00  \n" +
        "7f 00 00 7f  00 7F 7F 7F  7F 7F 7f 7f  00 7F 7F 7F  \n" +
        "7F 7F 7F 00  00 7F 7F 7F  7F 7F 00 7f  00"
    ];
    var data = [Object(), Object(), Object()];

    for (i = 0; i < 3; i++) {
        var ok = true;
        var split = data_strings[i].split(/\s+/);
        HIDDebug("i" + i + " " + split);
        data[i].length = split.length;
        for (j = 0; j < split.length; j++) {
            var byte_str = split[j];
            if (byte_str.length !== 2) {
                ok = false;
                HIDDebug("not two characters?? " + byte_str);
            }
            var b = parseInt(byte_str, 16);
            if (b < 0 || b > 255) {
                ok = false;
                HIDDebug("number out of range: " + byte_str + " " + b);
            }
            data[i][j] = b;
        }
        if (ok) {
            controller.send(data[i], data[i].length, 0x80 + i);
        }
    }
};

TraktorS4MK2.shutdown = function() {
    var packet_lengths = [53, 63, 61];
    for (i = 0; i < packet_lengths.length; i++) {
        var packet_length = packet_lengths[i];
        var data = Object();
        data.length = packet_length;
        data[0] = 0x80 + i;
        for (j = 1; j < packet_length; j++) {
            data[j] = 0;
        }
        // Keep USB light on though.
        if (i === 0) {
            data[0x2A] = 0x7F;
        }
        controller.send(data, packet_length, 0);
    }
};

// Called by Mixxx -- mandatory function to receive anything from HID
TraktorS4MK2.incomingData = function(data, length) {
    // Packets of 21 bytes are message 0x01 and can be handed off right away
    if (length === 21 || length === 79) {
        TraktorS4MK2.controller.parsePacket(data, length);
        return;
    }

    // Packets of 64 bytes and 15 bytes are partials.  We have to save the 64 byte portion and then
    // append the 15 bytes when we get it.
    if (length === 64) {
        this.partial_packet = data;
        return;
    }

    if (length === 15) {
        if (this.partial_packet.length !== 64) {
            HIDDebug("Traktor S4MK2: Received second half of message but don't have first half, ignoring");
            return;
        }
        // packet data is a javascript Object with properties that are integers (!).  So it's actually
        // unordered data (!!).  So "appending" is just setting more properties.
        partial_length = this.partial_packet.length;
        for (var i = 0; i < length; i++) {
            this.partial_packet[partial_length + i] = data[i];
        }
        TraktorS4MK2.controller.parsePacket(this.partial_packet, partial_length + length);
        // Clear out the partial packet
        this.partial_packet = Object();
        return;
    }
    if (length === 79) {
        // Windows seems to get the packet of length 79, so parse as one:
        TraktorS4MK2.controller.parsePacket(data, data.length);
        return;
    }
    HIDDebug("Traktor S4MK2: Unhandled packet size: " + length);
};

// The short message handles buttons and jog wheels.
TraktorS4MK2.shortMessageCallback = function(packet, data) {
    for (name in data) {
        field = data[name];
        // Rewrite group name from "deckX" to "[ChannelY]"
        group = TraktorS4MK2.getGroupFromButton(field.id);
        field.group = group;
        if (field.name === "!jog_wheel") {
            TraktorS4MK2.controller.processControl(field);
            continue;
        }

        TraktorS4MK2.controller.processButton(field);
    }
};

// There are no buttons handled by the long message, so this is a little simpler.  (Even though
// this is very similar to the other handler, it's easier to keep them separate to know what's
// a control and what's a button.
TraktorS4MK2.longMessageCallback = function(packet, data) {
    for (name in data) {
        field = data[name];
        // Rewrite group name from "deckX" to "[ChannelY]"
        group = TraktorS4MK2.getGroupFromButton(field.id);
        field.group = group;
        TraktorS4MK2.controller.processControl(field);
    }
};

// Utility function for converting mappings like "deck1.play" into "[ChannelX].play" based
// on the state of the deck switches.
TraktorS4MK2.getGroupFromButton = function(name) {
    //HIDDebug("deckswitch status " + this.controller.left_deck_C + " " + this.controller.right_deck_D);
    split = name.split(".");
    if (split.length !== 2) {
        HIDDebug("Traktor S4MK2: Tried to set from simple packet but not exactly one period in name: " + name);
        return;
    }

    if (split[0][0] === "[") {
        return split[0];
    } else if (split[0] === "deck1") {
        if (TraktorS4MK2.controller.left_deck_C) {
            return "[Channel3]";
        } else {
            return "[Channel1]";
        }
    } else if (split[0] === "deck2") {
        if (TraktorS4MK2.controller.right_deck_D) {
            return "[Channel4]";
        } else {
            return "[Channel2]";
        }
    } else {
        HIDDebug("Traktor S4MK2: Unrecognized packet group: " + split[0]);
        return "";
    }
};

TraktorS4MK2.shiftHandler = function(field) {
    var group = field.id.split(".")[0];
    TraktorS4MK2.controller.shift_pressed[group] = field.value;
    TraktorS4MK2.outputCallback(field.value, field.group, "!shift");
};

TraktorS4MK2.deckSwitchHandler = function(field) {
    if (field.value === 0) {
        return;
    }

    // The group is the currently-assigned value, so set the variable to the opposite.
    if (field.group === "[Channel1]") {
        TraktorS4MK2.controller.left_deck_C = true;
        TraktorS4MK2.lightDeck("[Channel3]");
        engine.softTakeoverIgnoreNextValue("[Channel3]", "rate");
    } else if (field.group === "[Channel3]") {
        TraktorS4MK2.controller.left_deck_C = false;
        TraktorS4MK2.lightDeck("[Channel1]");
        engine.softTakeoverIgnoreNextValue("[Channel1]", "rate");
    } else if (field.group === "[Channel2]") {
        TraktorS4MK2.controller.right_deck_D = true;
        TraktorS4MK2.lightDeck("[Channel4]");
        engine.softTakeoverIgnoreNextValue("[Channel4]", "rate");
    } else if (field.group === "[Channel4]") {
        TraktorS4MK2.controller.right_deck_D = false;
        TraktorS4MK2.lightDeck("[Channel2]");
        engine.softTakeoverIgnoreNextValue("[Channel2]", "rate");
    } else {
        HIDDebug("Traktor S4MK2: Unrecognized packet group: " + field.group);
    }
};

TraktorS4MK2.loadTrackHandler = function(field) {
    var split = field.id.split(".");
    var group = split[0];
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        engine.setValue(field.group, "eject", field.value);
    } else {
        engine.setValue(field.group, "LoadSelectedTrack", field.value);
    }
};

TraktorS4MK2.syncEnabledHandler = function(field) {
    var now = Date.now();

    var split = field.id.split(".");
    var group = split[0];
    // If shifted, just toggle.
    // TODO(later version): actually make this enable explicit master.
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        if (field.value === 0) {
            return;
        }
        var synced = engine.getValue(field.group, "sync_enabled");
        engine.setValue(field.group, "sync_enabled", !synced);
    } else {
        if (field.value === 1) {
            TraktorS4MK2.controller.sync_enabled_time[field.group] = now;
            engine.setValue(field.group, "sync_enabled", 1);
        } else {
            var cur_enabled = engine.getValue(field.group, "sync_enabled");
            if (!cur_enabled) {
                // If disabled, and switching to disable... stay disabled.
                engine.setValue(field.group, "sync_enabled", 0);
                return;
            }
            // was enabled, and button has been let go.  maybe latch it.
            if (now - TraktorS4MK2.controller.sync_enabled_time[field.group] > 300) {
                engine.setValue(field.group, "sync_enabled", 1);
                return;
            }
            engine.setValue(field.group, "sync_enabled", 0);
        }
    }
};

TraktorS4MK2.cueHandler = function(field) {
    var split = field.id.split(".");
    var group = split[0];
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        if (TraktorS4MK2.ShiftCueButtonAction === "REWIND") {
            if (field.value === 0) {
                return;
            }
            engine.setValue(field.group, "start_stop", 1);
        } else if (TraktorS4MK2.ShiftCueButtonAction === "REVERSEROLL") {
            engine.setValue(field.group, "reverseroll", field.value);
        } else {
            print ("Traktor S4 WARNING: Invalid ShiftCueButtonAction picked.  Must be either REWIND " +
            "or REVERSEROLL");
        }
    } else {
        engine.setValue(field.group, "cue_default", field.value);
    }
};

TraktorS4MK2.playHandler = function(field) {
    if (field.value === 0) {
        return;
    }
    var split = field.id.split(".");
    var group = split[0];
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        var locked = engine.getValue(field.group, "keylock");
        engine.setValue(field.group, "keylock", !locked);
    } else {
        var playing = engine.getValue(field.group, "play");
        var deckNumber = TraktorS4MK2.controller.resolveDeck(group);
        // Failsafe to disable scratching in case the finishJogTouch timer has not executed yet
        // after a backspin.
        if (engine.isScratching(deckNumber)) {
            engine.scratchDisable(deckNumber, false);
        }
        engine.setValue(field.group, "play", !playing);
    }
};

TraktorS4MK2.previewDeckHandler = function(field) {
    if (field.value === 0) {
        return;
    }
    // TODO: figure out a way to know if the browse position has changed.  If not, the preview
    // button should pause / resume. If it has changed, preview button loads new track.
    /*if (engine.getValue("[PreviewDeck1]", "play")) {
    engine.setValue("[PreviewDeck1]", "cue_gotoandstop", 1);
    engine.setValue("[PreviewDeck1]", "cue_gotoandstop", 0);
} else {*/
    engine.setValue("[PreviewDeck1]", "LoadSelectedTrackAndPlay", 1);
    engine.setValue("[PreviewDeck1]", "LoadSelectedTrackAndPlay", 0);
//}
};

// Jog wheel touch code taken from VCI400.  It should be moved into common-hid-packet-parser.js
TraktorS4MK2.jogTouchHandler = function(field) {
    if (TraktorS4MK2.controller.wheelTouchInertiaTimer[field.group] != 0) {
        // The wheel was touched again, reset the timer.
        engine.stopTimer(TraktorS4MK2.controller.wheelTouchInertiaTimer[field.group]);
        TraktorS4MK2.controller.wheelTouchInertiaTimer[field.group] = 0;
    }
    var play = engine.getValue(group, "play");

    if (field.value !== 0) {
        var deckNumber = TraktorS4MK2.controller.resolveDeck(group);
        if (play != 0) {
            TraktorS4MK2.slipAutoHandler(field.group, 1);
        }
        engine.scratchEnable(deckNumber, 1024, 33.3333, 0.125, 0.125/8, true);
    } else {
        // The wheel touch sensor can be overly sensitive, so don't release scratch mode right away.
        // Depending on how fast the platter was moving, lengthen the time we'll wait.
        var scratchRate = Math.abs(engine.getValue(field.group, "scratch2"));
        // Note: inertiaTime multiplier is controller-specific and should be factored out.
        var inertiaTime = Math.pow(1.8, scratchRate) * 2;
        if (inertiaTime < 100) {
            // Just do it now.
            TraktorS4MK2.finishJogTouch(field.group);
        } else {
            TraktorS4MK2.controller.wheelTouchInertiaTimer[field.group] = engine.beginTimer(
                inertiaTime, () => { TraktorS4MK2.finishJogTouch(field.group); }, true);
        }
    }
};

TraktorS4MK2.finishJogTouch = function(group) {
    TraktorS4MK2.controller.wheelTouchInertiaTimer[group] = 0;
    var deckNumber = TraktorS4MK2.controller.resolveDeck(group);
    // No vinyl button (yet)
    /*if (this.vinylActive) {
    // Vinyl button still being pressed, don't disable scratch mode yet.
    this.wheelTouchInertiaTimer[group] = engine.beginTimer(
    100, "VestaxVCI400.Decks." + this.deckIdentifier + ".finishJogTouch()", true);
    return;
    }*/
    var play = engine.getValue(group, "play");
    if (play != 0) {
        // If we are playing, just hand off to the engine.
        engine.scratchDisable(deckNumber, true);
        TraktorS4MK2.slipAutoHandler(field.group, 0);

    } else {
        // If things are paused, there will be a non-smooth handoff between scratching and jogging.
        // Instead, keep scratch on until the platter is not moving.
        var scratchRate = Math.abs(engine.getValue(group, "scratch2"));
        if (scratchRate < 0.01) {
            // The platter is basically stopped, now we can disable scratch and hand off to jogging.
            engine.scratchDisable(deckNumber, false);
            // Handle auto slip mode
        } else {
            // Check again soon.
            TraktorS4MK2.controller.wheelTouchInertiaTimer[group] = engine.beginTimer(
                100, () => { TraktorS4MK2.finishJogTouch(group); }, true);
        }
    }
};

TraktorS4MK2.jogMoveHandler = function(field) {
    var deltas = TraktorS4MK2.wheelDeltas(field.group, field.value);
    var tick_delta = deltas[0];
    var time_delta = deltas[1];

    var velocity = TraktorS4MK2.scalerJog(tick_delta, time_delta);
    engine.setValue(field.group, "jog", velocity);
    if (engine.getValue(field.group, "scratch2_enable")) {
        var deckNumber = TraktorS4MK2.controller.resolveDeck(group);
        engine.scratchTick(deckNumber, tick_delta);
    }
};

TraktorS4MK2.wheelDeltas = function(group, value) {
    // When the wheel is touched, four bytes change, but only the first behaves predictably.
    // It looks like the wheel is 1024 ticks per revolution.
    var tickval = value & 0xFF;
    var timeval = value >>> 16;
    var prev_tick = 0;
    var prev_time = 0;

    if (group[8] === "1" || group[8] === "3") {
        prev_tick = TraktorS4MK2.controller.last_tick_val[0];
        prev_time = TraktorS4MK2.controller.last_tick_time[0];
        TraktorS4MK2.controller.last_tick_val[0] = tickval;
        TraktorS4MK2.controller.last_tick_time[0] = timeval;
    } else {
        prev_tick = TraktorS4MK2.controller.last_tick_val[1];
        prev_time = TraktorS4MK2.controller.last_tick_time[1];
        TraktorS4MK2.controller.last_tick_val[1] = tickval;
        TraktorS4MK2.controller.last_tick_time[1] = timeval;
    }

    if (prev_time > timeval) {
        // We looped around.  Adjust current time so that subtraction works.
        timeval += 0x10000;
    }
    var time_delta = timeval - prev_time;
    if (time_delta === 0) {
        // Spinning too fast to detect speed!  By not dividing we are guessing it took 1ms.
        time_delta = 1;
    }

    var tick_delta = 0;
    if (prev_tick >= 200 && tickval <= 100) {
        tick_delta = tickval + 256 - prev_tick;
    } else if (prev_tick <= 100 && tickval >= 200) {
        tick_delta = tickval - prev_tick - 256;
    } else {
        tick_delta = tickval - prev_tick;
    }
    //HIDDebug(group + " " + tickval + " " + prev_tick + " " + tick_delta);
    return [tick_delta, time_delta];
};

TraktorS4MK2.scalerJog = function(tick_delta, time_delta) {
    // If it's playing nudge
    if (engine.getValue(group, "play")) {
        return (tick_delta / time_delta) / 3;
    } else {
        //If shift pressed, fast search through tracks
        // otherwise search normal speed
        if (TraktorS4MK2.controller.shift_pressed["deck1"] ||
        TraktorS4MK2.controller.shift_pressed["deck2"]) {
            return (tick_delta / time_delta) * 20.0;
        } else {
            return (tick_delta / time_delta) * 2.0;
        }
    }
};

TraktorS4MK2.hotcueHandler = function(field) {
    var group = field.id.split(".")[0];
    var buttonNumber = parseInt(field.name[field.name.length - 1]);
    TraktorS4MK2.slipAutoHandler(field.group, field.value);
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        engine.setValue(field.group, "hotcue_" + buttonNumber + "_clear", field.value);
    } else {
        engine.setValue(field.group, "hotcue_" + buttonNumber + "_activate", field.value);
    }

};

TraktorS4MK2.remixHandler = function(field) {
    var group = field.id.split(".")[0];

    if (TraktorS4MK2.RemixSlotButtonAction === "SAMPLES") {
        if (field.value !== 1) {
            return;
        }
        var buttonNumber = parseInt(field.name[field.name.length - 1]);
        if (group === "deck2") {
            buttonNumber = buttonNumber + 4;
        }
        if (TraktorS4MK2.controller.shift_pressed[group]) {
            if (engine.getValue("[Sampler" + buttonNumber + "]", "play")) {
                engine.setValue("[Sampler" + buttonNumber + "]", "start_stop", 1);
            } else {
                engine.setValue("[Sampler" + buttonNumber + "]", "eject", 1);
            }
        } else {
            if (engine.getValue("[Sampler" + buttonNumber + "]", "track_loaded")) {
                engine.setValue("[Sampler" + buttonNumber + "]", "cue_gotoandplay", 1);
            } else {
                engine.setValue("[Sampler" + buttonNumber + "]", "LoadSelectedTrack", 1);
            }
        }
    } else if (TraktorS4MK2.RemixSlotButtonAction === "LOOPROLLS") {
        var buttonNumber = parseInt(field.name[field.name.length - 1]);
        // If shift is held, create a quick loop of convenient size
        if (TraktorS4MK2.controller.shift_pressed[group]) {
            if (field.value !== 1) {
                return;
            }
            var loop_size = Math.pow(2, buttonNumber + 1);
            engine.setValue(field.group, "beatloop_" + loop_size + "_activate", field.value);
        } else {
            var loop_size = Math.pow(2, buttonNumber - 4);
            engine.setValue(field.group, "beatlooproll_" + loop_size + "_activate", field.value);
        }
    } else {
        print ("Traktor S4 WARNING: Invalid RemixSlotButtonAction picked.  Must be either SAMPLES " +
        "or LOOPROLLS");
    }
};

TraktorS4MK2.quantizeHandler = function(field) {
    if (field.value === 0) {
        return;
    }
    TraktorS4MK2.master_quantize = !TraktorS4MK2.master_quantize;
    engine.setValue("[Channel1]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel2]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel3]", "quantize", TraktorS4MK2.master_quantize);
    engine.setValue("[Channel4]", "quantize", TraktorS4MK2.master_quantize);
    TraktorS4MK2.controller.setOutput("[Master]", "!quantize", 0x7F * TraktorS4MK2.master_quantize, true);
};

TraktorS4MK2.snapHandler = function(field) {
    if (field.value === 0) {
        return;
    }
    library_maximized = engine.getValue("[Skin]", "show_maximized_library");
    engine.setValue("[Skin]", "show_maximized_library", !library_maximized);
};

TraktorS4MK2.FXButtonHandler = function(field) {
    if (field.value) {
        if (
            TraktorS4MK2.controller.shift_pressed["deck1"] ||
            TraktorS4MK2.controller.shift_pressed["deck2"]
        ) {
            engine.setValue(field.group, "effect_selector", 1);
        } else {
            engine.setValue(field.group, "enabled", !engine.getValue(field.group, "enabled"));
        }
    }
    TraktorS4MK2.lightDeck(field.group);
};

TraktorS4MK2.FXMetaHandler = function(field) {
    engine.setValue(field.group, "meta", field.value / parseFloat(4096));
};


TraktorS4MK2.outputFXCallback = function(value, group, key) {
    TraktorS4MK2.controller.setOutput(group, key, value * 0x7F, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.callbackPregain = function(field) {
    // TODO: common-hid-packet-parser looks like it should do deltas, but I can't get them to work.
    prev_pregain = TraktorS4MK2.controller.prev_pregain[field.group];
    TraktorS4MK2.controller.prev_pregain[field.group] = field.value;
    var delta = 0;
    if (prev_pregain === 15 && field.value === 0) {
        delta = 0.05;
    } else if (prev_pregain === 0 && field.value === 15) {
        delta = -0.05;
    } else if (field.value > prev_pregain) {
        delta = 0.05;
    } else {
        delta = -0.05;
    }

    if (
        TraktorS4MK2.controller.shift_pressed["deck1"] ||
        TraktorS4MK2.controller.shift_pressed["deck2"]
    ) {
        if (delta > 0) {
            engine.setValue(group, "beats_translate_later", true);
        } else if (delta < 0) {
            engine.setValue(group, "beats_translate_earlier", true);
        }
    } else if (TraktorS4MK2.controller.play_shift_pressed === 1) {
        var bpm_sensitivity_multipler = 50;
        if (delta > 0) {
            for (var i = 0; i < bpm_sensitivity_multipler; i++) {
                engine.setValue(group, "beats_adjust_faster", true);
            }
        } else if (delta < 0) {
            for (var i = 1; i < bpm_sensitivity_multipler; i++) {
                engine.setValue(group, "beats_adjust_slower", true);
            }
        }
    } else {
        var cur_pregain = engine.getValue(group, "pregain");
        engine.setValue(group, "pregain", cur_pregain + delta);
    }

};

TraktorS4MK2.callbackLoopMove = function(field) {
    // TODO: common-hid-packet-parser looks like it should do deltas, but I can't get them to work.
    var split = field.id.split(".");
    var group = split[0];
    prev_loopmove = TraktorS4MK2.controller.prev_loopmove[group];
    TraktorS4MK2.controller.prev_loopmove[group] = field.value;
    var delta = 0;
    if (prev_loopmove === 15 && field.value === 0) {
        delta = 1;
    } else if (prev_loopmove === 0 && field.value === 15) {
        delta = -1;
    } else if (field.value > prev_loopmove) {
        delta = 1;
    } else {
        delta = -1;
    }

    if (TraktorS4MK2.controller.shift_pressed[group]) {
        var beatjump_size = engine.getValue(field.group, "beatjump_size");
        if (delta === 1) {
            engine.setValue(field.group, "beatjump_size", beatjump_size * 2);
        } else {
            engine.setValue(field.group, "beatjump_size", beatjump_size / 2);
        }
    } else {
        if (delta === 1) {
            script.triggerControl(field.group, "beatjump_forward");
        } else {
            script.triggerControl(field.group, "beatjump_backward");
        }
    }
};

TraktorS4MK2.loopActivateHandler = function(field) {
    var split = field.id.split(".");
    var group = split[0];
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        engine.setValue(field.group, "reloop_andstop", field.value);
    } else {
        var looping = engine.getValue(field.group, "loop_enabled");
        if (field.value === 1) {
            TraktorS4MK2.slipAutoHandler(field.group, !looping);
        }
        engine.setValue(field.group, "reloop_toggle", field.value);

    }

};

TraktorS4MK2.sendLoopSizeMessage = function(deck, firstChar, secondChar, firstDot, secondDot) {
    // display_num must be a string with two characters
    // Do the second number first
    TraktorS4MK2.displayCharLoopCounter(deck, 0, firstChar);
    TraktorS4MK2.displayCharLoopCounter(deck, 1, secondChar);
    TraktorS4MK2.displayCharLoopDot(deck, 0, firstDot);
    TraktorS4MK2.displayCharLoopDot(deck, 1, secondDot);
};

TraktorS4MK2.displayCharLoopCounter = function(deck, charPos, character) {
    // charPost is 0 or 1 for first or second character on the display
    // the display is placed like this:
    // o  -- 4 --
    //   |        |
    //   5        3
    //   |        |
    //    -- 1 --
    //   |        |
    //   6        2
    //   |        |
    //    -- 7 --
    //  Where the numbers represent each segment of the display
    //  and the dot before it is 0 (but this is dealt with in displayCharLoopDot)

    var numArray = {
        "": [], //empty
        0: [2, 3, 4, 5, 6, 7],
        1: [2, 3],
        2: [1, 3, 4, 6, 7],
        3: [1, 2, 3, 4, 7],
        4: [1, 2, 3, 5],
        5: [4, 5, 1, 2, 7],
        6: [4, 5, 1, 2, 6, 7],
        7: [4, 3, 2],
        8: [1, 2, 3, 4, 5, 6, 7],
        9: [5, 4, 1, 3, 2, 7],
        // Add a few special characters
        "h": [5, 1, 6, 2],
        "n": [6, 1, 2],
        "o": [6, 1, 2, 7],
        "-": [1],
        "b": [5, 6, 7, 2, 1],
        "c": [1, 6, 7],
        "u": [6, 2, 7],
    };

    for (j = 0; j < 8; j++) {
        loop_key = 8*charPos + j;
        var key = "!loopSize" + loop_key;
        TraktorS4MK2.controller.setOutput(
            deck, key, (numArray[character].indexOf(j) > -1)*0x7F, // if it's in the array turn it on, off otherwise
            !TraktorS4MK2.controller.freeze_lights
        );
    }
};

TraktorS4MK2.displayCharLoopDot = function(deck, charPos, on) {
    var key = "!loopSize" + 8*charPos;
    TraktorS4MK2.controller.setOutput(
        deck, key, on*0x7F,
        !TraktorS4MK2.controller.freeze_lights
    );
};

TraktorS4MK2.callbackLoopSize = function(field) {
    var split = field.id.split(".");
    var group = split[0];
    prev_loopsize = TraktorS4MK2.controller.prev_loopsize[group];
    TraktorS4MK2.controller.prev_loopsize[group] = field.value;
    var delta = 0;
    if (prev_loopsize === 15 && field.value === 0) {
        delta = 1;
    } else if (prev_loopsize === 0 && field.value === 15) {
        delta = -1;
    } else if (field.value > prev_loopsize) {
        delta = 1;
    } else {
        delta = -1;
    }

    if (TraktorS4MK2.controller.shift_pressed[group]) {
        if (delta === 1) {
            script.triggerControl(field.group, "pitch_up_small");
        } else {
            script.triggerControl(field.group, "pitch_down_small");
        }
    } else {
        if (delta === 1) {
            script.triggerControl(field.group, "loop_double");
        } else {
            script.triggerControl(field.group, "loop_halve");
        }
    }
};

TraktorS4MK2.loopSetHandler = function(field) {
    var split = field.id.split(".");
    var group = split[0];
    if (TraktorS4MK2.controller.shift_pressed[group]) {
        engine.setValue(field.group, "pitch_adjust_set_default", field.value);
    } else {
        engine.setValue(field.group, "beatloop_activate", field.value);
    }
};

TraktorS4MK2.callbackBrowse = function(field) {
    // TODO: common-hid-packet-parser looks like it should do deltas, but I can't get them to work.
    prev_browse = TraktorS4MK2.controller.prev_browse;
    TraktorS4MK2.controller.prev_browse = field.value;
    var delta = 0;
    if (prev_browse === 15 && field.value === 0) {
        delta = 1;
    } else if (prev_browse === 0 && field.value === 15) {
        delta = -1;
    } else if (field.value > prev_browse) {
        delta = 1;
    } else {
        delta = -1;
    }
    if (
        TraktorS4MK2.controller.shift_pressed["deck1"] ||
        TraktorS4MK2.controller.shift_pressed["deck2"]
    ) {
        engine.setValue("[Library]", "MoveFocus", delta);
    } else {
        engine.setValue("[Library]", "MoveVertical", delta);
    }
};

TraktorS4MK2.scalerParameter = function(group, name, value) {
    return script.absoluteLin(value, 0, 1, 16, 4080);
};
// Tell the HIDController script to use setParameter instead of setValue.
TraktorS4MK2.scalerParameter.useSetParameter = true;

TraktorS4MK2.scalerVolume = function(group, name, value) {
    if (group === "[Master]") {
        return script.absoluteNonLin(value, 0, 1, 4, 16, 4080);
    } else {
        return script.absoluteNonLin(value, 0, 0.25, 1, 16, 4080);
    }
};

TraktorS4MK2.scalerSlider = function(group, name, value) {
    return script.absoluteLin(value, -1, 1, 16, 4080);
};

TraktorS4MK2.resolveDeckIfActive = function(group) {
    var controller = TraktorS4MK2.controller;
    if (group === "[Channel1]") {
        if (controller.left_deck_C) {
            return undefined;
        }
        return "deck1";
    } else if (group === "[Channel3]") {
        if (!controller.left_deck_C) {
            return undefined;
        }
        return "deck1";
    } else if (group === "[Channel2]") {
        if (controller.right_deck_D) {
            return undefined;
        }
        return "deck2";
    } else if (group === "[Channel4]") {
        if (!controller.right_deck_D) {
            return undefined;
        }
        return "deck2";
    }
    return undefined;
};

TraktorS4MK2.outputChannelCallback = function(value, group, key) {
    var led_value = 0x09;
    if (value) {
        led_value = 0x7F;
    }
    TraktorS4MK2.controller.setOutput(group, key, led_value, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.outputChannelCallbackDark = function(value, group, key) {
    var led_value = 0x00;
    if (value) {
        led_value = 0x7F;
    }
    TraktorS4MK2.controller.setOutput(group, key, led_value, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.outputCallback = function(value, group, key) {
    var deck_group = TraktorS4MK2.resolveDeckIfActive(group);
    if (deck_group === undefined) {
        return;
    }

    var led_value = 0x09;
    if (value) {
        led_value = 0x7F;
    }
    TraktorS4MK2.controller.setOutput(deck_group, key, led_value, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.outputCallbackLoop = function(value, group, key) {
    var deck_group = TraktorS4MK2.resolveDeckIfActive(group);
    if (deck_group === undefined) {
        return;
    }

    var led_value = 0x09;
    if (engine.getValue(group, "loop_enabled")) {
        led_value = 0x7F;
    }
    TraktorS4MK2.controller.setOutput(deck_group, key, led_value, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.outputCallbackDark = function(value, group, key) {
    var deck_group = TraktorS4MK2.resolveDeckIfActive(group);
    if (deck_group === undefined) {
        return;
    }

    var led_value = 0x00;
    if (value) {
        led_value = 0x7F;
    }
    TraktorS4MK2.controller.setOutput(deck_group, key, led_value, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.outputCueCallback = function(value, group, key) {
    var deck_group = TraktorS4MK2.resolveDeckIfActive(group);
    if (deck_group === undefined) {
        return;
    }

    var RGB_value = [0, 0, 0];
    // Use different colors for decks 1/2 and 3/4 that match LateNight (red and blue).
    if (group === "[Channel1]" || group === "[Channel2]") {
        if (value === 1) {
            RGB_value = [0x7F, 0x04, 0x04];
        } else {
            RGB_value = [0x08, 0x01, 0x01];
        }
    } else {
        if (value === 1) {
            RGB_value = [0x04, 0x04, 0x7F];
        } else {
            RGB_value = [0x01, 0x01, 0x08];
        }
    }

    TraktorS4MK2.controller.setOutput(deck_group, key, RGB_value[0], false);
    TraktorS4MK2.controller.setOutput(deck_group, "!" + key + "_G", RGB_value[1], false);
    TraktorS4MK2.controller.setOutput(deck_group, "!" + key + "_B", RGB_value[2], !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.onVuMeterChanged = function(value, group, key) {
    // This handler is called a lot so it should be as fast as possible.

    // VU is drawn on 6 segments, the 7th indicates clip.
    var VuOffsets = {
        "[Channel1]": 0x09,
        "[Channel2]": 0x11,
        "[Channel3]": 0x01,
        "[Channel4]": 0x19
    };

    // Figure out number of fully-illuminated segments.
    var scaledValue = value * 6.0;
    var fullIllumCount = Math.floor(scaledValue);

    // Figure out how much the partially-illuminated segment is illuminated.
    var partialIllum = (scaledValue - fullIllumCount) * 0x7F;

    for (i = 0; i < 6; i++) {
        var key = "!" + "VuMeter" + i;
        if (i < fullIllumCount) {
            // Don't update lights until they're all done, so the last term is false.
            TraktorS4MK2.controller.setOutput(group, key, 0x7F, false);
        } else if (i === fullIllumCount) {
            TraktorS4MK2.controller.setOutput(group, key, partialIllum, false);
        } else {
            TraktorS4MK2.controller.setOutput(group, key, 0x00, false);
        }
    }
    TraktorS4MK2.controller.OutputPackets["output1"].send();
};

TraktorS4MK2.onLoopEnabledChanged = function(value, group, key) {
    TraktorS4MK2.outputCallbackLoop(value, group, "loop_in");
    TraktorS4MK2.outputCallbackLoop(value, group, "loop_out");
    TraktorS4MK2.slipAutoHandler(group, value);
};

TraktorS4MK2.onLoopSizeChanged = function(value, group, key) {
    var deck = TraktorS4MK2.resolveDeckIfActive(group);
    //deal with single digit values
    if (value.toString().length === 1) {
        TraktorS4MK2.sendLoopSizeMessage(deck, "", value, false, false);
        // values with two digits
    } else if (value.toString().length === 2) {
        TraktorS4MK2.sendLoopSizeMessage(deck, value.toString().split("")[0], value.toString().split("")[1], false, false);
        // deal with fraction beats
    } else if (1 > value > 0) {
        var inverse_value = 1/value;
        if (inverse_value % 1 === 0) {
            if (inverse_value.toString().length === 1) {
                TraktorS4MK2.sendLoopSizeMessage(deck, "", inverse_value, false, true);
            } else if (inverse_value.toString().length === 2) {
                TraktorS4MK2.sendLoopSizeMessage(deck, inverse_value.toString().split("")[0], inverse_value.toString().split("")[1], false, true);
            }
        }
        // deal with larger Loops
    } else if (value.toString().length > 2) {
        TraktorS4MK2.sendLoopSizeMessage(deck, value.toString().split("")[0], value.toString().split("")[1], true, true);
    }
};

TraktorS4MK2.loopSizeSet = function(group) {
    TraktorS4MK2.onLoopSizeChanged(engine.getValue(group, "beatloop_size"), group);
};

TraktorS4MK2.onRecordingChanged = function(value, group, control) {
    TraktorS4MK2.outputChannelCallback(value, "[Recording]", "status");
    TraktorS4MK2.controller.setOutput("deck1", "!on_air", value*0x7F, !TraktorS4MK2.controller.freeze_lights);
    TraktorS4MK2.controller.setOutput("deck2", "!on_air", value*0x7F, !TraktorS4MK2.controller.freeze_lights);
};

TraktorS4MK2.slipHandler = function(field) {
    // Change on touchdown
    if (field.value === 0x01) {
        var group = field.id.split(".")[0];
        if (TraktorS4MK2.controller.play_shift_pressed === 1) {
            TraktorS4MK2.controller.autoSlipMode[field.group] ^= true;
            TraktorS4MK2.lightSlipAuto(field.group);
        } else if (TraktorS4MK2.controller.shift_pressed[group] === 1)   {
            var prev_range = TraktorS4MK2.controller.tempoRange[field.group];
            if (prev_range <= 0) {
                prev_range = 0;
                TraktorS4MK2.controller.tempoRange[field.group] = 0;
            } else if (prev_range > 0) {
                var new_range = prev_range - 1;
                var range_value = TraktorS4MK2.controller.tempoRangeList[new_range] / 100;
                TraktorS4MK2.controller.tempoRange[field.group] = new_range;
                engine.setValue(field.group, "rateRange", range_value);
            }

        } else {
            engine.setValue(field.group, "slip_enabled", !engine.getValue(field.group, "slip_enabled"));
        }
    }
    // Do nothing on touchup
};

TraktorS4MK2.resetHandler = function(field) {
    var group = field.id.split(".")[0];
    if (field.value === 0x01) {
        if (TraktorS4MK2.controller.shift_pressed[group] === 1) {
            var prev_range = TraktorS4MK2.controller.tempoRange[field.group];
            print("Previous range " + prev_range);
            if (prev_range >= TraktorS4MK2.controller.tempoRangeList.length - 1) {
                prev_range = TraktorS4MK2.controller.tempoRangeList.length - 1;
                TraktorS4MK2.controller.tempoRange[field.group] = prev_range;
            } else {
                var new_range = prev_range + 1;
                var range_value = TraktorS4MK2.controller.tempoRangeList[new_range] / 100;
                TraktorS4MK2.controller.tempoRange[field.group] = new_range;
                engine.setValue(field.group, "rateRange", range_value);
            }
        } else {
            engine.setValue(field.group, "reset_key", field.value);
        }
    }
};

TraktorS4MK2.pregainResetHandler = function(field) {


    // Don't do something on push release
    if (field.value === 0) {
        return;
    }
    if (TraktorS4MK2.controller.play_shift_pressed) {
        // If the 'play modifier' button is held down round the BPM
        var bpm = engine.getValue(group, "bpm");
        var rounded_value = Math.round(bpm);
        var delta = (bpm - rounded_value)*100;
        if (delta > 0) {
            for (var i = 0; i < delta; i++) {
                engine.setValue(group, "beats_adjust_slower", true);
            }
        } else if (delta < 0) {
            for (var i = 0; i < delta; i++) {
                engine.setValue(group, "beats_adjust_faster", true);
            }
        }


    } else {
        // Otherwise reset the gain on the channel
        engine.setValue(group, "pregain", "1.0");
    }
};

TraktorS4MK2.lightSlipAuto = function(group) {
    var decknum = TraktorS4MK2.resolveDeckIfActive(group);
    if (TraktorS4MK2.controller.autoSlipMode[group] === 1) {
        print(decknum);
        TraktorS4MK2.controller.setOutput(decknum, "!remix", 0x7F, !TraktorS4MK2.controller.freeze_lights);
    } else {
        print("Turning off light");
        TraktorS4MK2.controller.setOutput(decknum, "!remix", 0x00, !TraktorS4MK2.controller.freeze_lights);
    }
};

TraktorS4MK2.slipAutoHandler = function(group, on) {
    if (TraktorS4MK2.controller.autoSlipMode[group] === 1) {
        engine.setValue(group, "slip_enabled", on);
    }
};

TraktorS4MK2.playLRButtonHandler = function(field) {
    TraktorS4MK2.controller.play_shift_pressed = field.value;
};
