Support Apple Media Service

[hathach]

https://developer.apple.com/library/content/documentation/CoreBluetooth/Reference/AppleMediaService_Reference/Specification/Specification.html

[Petros144]

` import BLEClient from "bleclient";
import BLEServer from "bleserver";
import {uuid} from "btutils";

const EntityID = {
Player: 0,
Queue: 1,
Track: 2
}
Object.freeze(EntityID);

const EntityUpdateFlags = {
Truncated: (1 << 0),
}
Object.freeze(EntityUpdateFlags);

const TrackAttributeID = {
Artist: 0,
Album: 1,
Title: 2,
Duration: 3
}
Object.freeze(TrackAttributeID);

const PlayerAttributeID = {
Name: 0,
PlaybackInfo: 1,
Volume: 2
}
Object.freeze(TrackAttributeID);

const RemoteCommandID = {
Play: 0,
Pause: 1,
TogglePlayPause: 2,
NextTrack: 3,
PreviousTrack: 4,
VolumeUp: 5,
VolumeDown: 6,
AdvanceRepeatMode: 7,
AdvanceShuffleMode: 8,
SkipForward: 9,
SkipBackward: 10,
LikeTrack: 11,
DislikeTrack: 12,
BookmarkTrack: 13
}
Object.freeze(RemoteCommandID);

const PlaybackState = {
Paused: 0,
Playing: 1,
Rewinding: 2,
FastForwarding: 3,
}
Object.freeze(PlaybackState);

const QueueAttributeID = {
Index: 0,
Count: 1,
ShuffleMode: 2,
RepeatMode: 3,
}
Object.freeze(QueueAttributeID);

const ShuffleMode = {
Off: 0,
One: 1,
All: 2,
}
Object.freeze(ShuffleMode);

const RepeatMode = {
Off: 0,
One: 1,
All: 2,
}
Object.freeze(RepeatMode);

class AMSAuthenticator extends BLEServer {
constructor(client) {
super();
this.client = client;
this.AMS_UUID = uuid89D3502B-0F36-433A-8EF4-C502AD55F8DC;
}
onReady() {
this.deviceName = "Moddable";
this.securityParameters = { mitm:true };
this.onDisconnected();
}
onConnected(device) {
this.device = device;
this.stopAdvertising();
}
onAuthenticated() {
this.client.onAuthenticated(this.device);
}
onDisconnected() {
this.startAdvertising({
advertisingData: {flags: 6, completeName: this.deviceName, solicitationUUID128List: [this.AMS_UUID]}
});
}
}
Object.freeze(AMSAuthenticator.prototype);

class AMSClient extends BLEClient {
constructor(device) {
super();
this.device = device;
this._supportedRemoteCommands = new Uint8Array;
}
onReady() {
this.AMS_UUID = uuid89D3502B-0F36-433A-8EF4-C502AD55F8DC;
this.REMOTE_COMMAND_CHARACTERISTIC_UUID = uuid9B3C81D8-57B1-4A8A-B8DF-0E56F7CA51C2;
this.ENTITY_UPDATE_CHARACTERISTIC_UUID = uuid2F7CABCE-808D-411F-9A0C-BB92BA96C102;
this.ENTITY_ATTRIBUTE_CHARACTERISTIC_UUID = uuidC6B2F38C-23AB-46D8-A6AB-A3A870BBD5D7;
this.securityParameters = { mitm:true };
}
onSecurityParameters() {
this.connect(this.device);
}
onConnected(device) {
device.discoverPrimaryService(this.AMS_UUID);
}
onServices(services) {
if (services.length)
services[0].discoverAllCharacteristics();
}
onCharacteristics(characteristics) {
characteristics.forEach(characteristic => {
let uuid = characteristic.uuid;
if (uuid.equals(this.REMOTE_COMMAND_CHARACTERISTIC_UUID))
this.remoteCommandCharacteristic = characteristic;
else if (uuid.equals(this.ENTITY_UPDATE_CHARACTERISTIC_UUID))
this.entityUpdateCharacteristic = characteristic;
else if (uuid.equals(this.ENTITY_ATTRIBUTE_CHARACTERISTIC_UUID))
this.entityAttributeCharacteristic = characteristic;
});
if (this.remoteCommandCharacteristic)
this.remoteCommandCharacteristic.enableNotifications();
}
onCharacteristicNotificationEnabled(characteristic) {
if (characteristic.uuid.equals(this.REMOTE_COMMAND_CHARACTERISTIC_UUID)) {
if (this.entityUpdateCharacteristic)
this.entityUpdateCharacteristic.enableNotifications();
}
else if (characteristic.uuid.equals(this.ENTITY_UPDATE_CHARACTERISTIC_UUID)) {
let update;
update = Uint8Array.of(EntityID.Track, TrackAttributeID.Artist, TrackAttributeID.Album, TrackAttributeID.Title, TrackAttributeID.Duration);
characteristic.writeWithoutResponse(update.buffer);
update = Uint8Array.of(EntityID.Player, PlayerAttributeID.PlaybackInfo);
characteristic.writeWithoutResponse(update.buffer);
}
}
onCharacteristicNotification(characteristic, buffer) {
if (characteristic.uuid.equals(this.ENTITY_UPDATE_CHARACTERISTIC_UUID)) {
let entityUpdate = new Uint8Array(buffer);
let entityID = entityUpdate[0];
let attributeID = entityUpdate[1];
let flags = entityUpdate[2];
let value = String.fromArrayBuffer(buffer.slice(3));

		if (EntityID.Track == entityID) {
			if (TrackAttributeID.Artist == attributeID)
				this._nextTrack = { artist:value };
			else if (TrackAttributeID.Album == attributeID)
				this._nextTrack.album = value;
			else if (TrackAttributeID.Title == attributeID)
				this._nextTrack.title = value;
			else if (TrackAttributeID.Duration == attributeID)
				this._nextTrack.duration = parseFloat(value);
			if (4 == Object.keys(this._nextTrack).length)
				this.onTrackChanged(this._nextTrack.artist, this._nextTrack.album, this._nextTrack.title, this._nextTrack.duration);
		}
		else if (EntityID.Player == entityID) {
			let parts = value.split(',');
			let playbackState = parseInt(parts[0]);
			let playbackRate = parseFloat(parts[1]);
			let elapsedTime = parseFloat(parts[2]);
			this.onPlaybackInfoChanged(playbackState, playbackRate, elapsedTime);
		}
	}
	else if (characteristic.uuid.equals(this.REMOTE_COMMAND_CHARACTERISTIC_UUID)) {
		this._supportedRemoteCommands = new Uint8Array(buffer);
	}
}
remoteCommand(command) {
	if (this._supportedRemoteCommands.includes(command))
		this.remoteCommandCharacteristic.writeWithoutResponse(Uint8Array.of(command).buffer);
}
onPlaybackInfoChanged(state, rate, elapsed) {
}
onTrackChanged(artist, album, title, duration) {
}

}
Object.freeze(AMSClient.prototype);

export {AMSAuthenticator, AMSClient, RemoteCommandID, PlaybackState, QueueAttributeID, ShuffleMode, RepeatMode};
`

[Petros144]

someone did this to the NRF52 but with the Nordic SDK

https://github.com/jimmywong2003/nrf5-ancs-ams-wristband-example

maybe this helps for easier Port.