BLEMIDI.hpp

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#pragma once
 
#ifdef ARDUINO
 
#ifndef ARDUINO_ARCH_ESP32
#error "MIDI over Bluetooth is only supported on ESP32 boards"
#endif
 
#include <BLE2902.h>
#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
 
#include <AH/Error/Error.hpp>
 
BEGIN_CS_NAMESPACE
 
// https://www.midi.org/specifications/item/bluetooth-le-midi
const char *SERVICE_UUID = "03b80e5a-ede8-4b33-a751-6ce34ec4c700";
const char *CHARACTERISTIC_UUID = "7772e5db-3868-4112-a1a9-f2669d106bf3";
 
constexpr const char *BLE_MIDI_NAME = "Control Surface (BLE)";
 
class BLEMIDI {
  public:
    ~BLEMIDI() {
        // TODO
    }
 
    void setServerCallbacks(BLEServerCallbacks *cb) {
        if (pServer == nullptr) {
            ERROR(F("Error: pServer has not been initialized"), 0x2020);
            return;
        }
        pServer->setCallbacks(cb);
    }
 
    void setCharacteristicsCallbacks(BLECharacteristicCallbacks *cb) {
        if (pCharacteristic == nullptr) {
            ERROR(F("Error: Characteristic has not been initialized"), 0x2021);
            return;
        }
        pCharacteristic->setCallbacks(cb);
    }
 
    void begin(BLEServerCallbacks *serverCallbacks,
               BLECharacteristicCallbacks *midiCallbacks) {
        DEBUGFN("Initializing BLE MIDI Interface");
        if (BLEDevice::getInitialized()) {
            ERROR(F("Error: BLEDevice is initialized already"), 0x2022);
            return; // TODO: What to do here?
        }
 
        // Initialize the BLE device
        BLEDevice::init(BLE_MIDI_NAME);
 
        // Create the BLE server
        pServer = BLEDevice::createServer();
        setServerCallbacks(serverCallbacks);
 
        // Create the BLE service
        BLEService *pService = pServer->createService(BLEUUID(SERVICE_UUID));
 
        // Create a BLE characteristic
        pCharacteristic = pService->createCharacteristic(
            BLEUUID(CHARACTERISTIC_UUID),
            BLECharacteristic::PROPERTY_READ |
                BLECharacteristic::PROPERTY_NOTIFY |
                BLECharacteristic::PROPERTY_WRITE_NR);
 
        // Create a BLE descriptor
        descriptor = new BLE2902();
        pCharacteristic->addDescriptor(descriptor);
        // descriptor.setNotifications(true);
        setCharacteristicsCallbacks(midiCallbacks);
 
        // Start the service
        pService->start();
 
        // Start advertising
        BLEAdvertising *pAdvertising = pServer->getAdvertising();
        pAdvertising->addServiceUUID(pService->getUUID());
        pAdvertising->start();
    }
 
    void notifyValue(uint8_t *data, size_t len) {
        pCharacteristic->setValue(data, len);
        pCharacteristic->notify();
    }
 
    std::string getValue() { return pCharacteristic->getValue(); }
 
  private:
    BLECharacteristic *pCharacteristic = nullptr;
    BLEServer *pServer = nullptr;
    BLE2902 *descriptor;
};
 
END_CS_NAMESPACE
 
#else
 
#include <Def/Def.hpp>
#include <gmock-wrapper.h>
#include <string>
 
class BLECharacteristic {
  public:
    MOCK_METHOD(std::string, getValue, ());
    MOCK_METHOD(void, setValue, (uint8_t * data, size_t len));
};
 
class BLECharacteristicCallbacks {
  public:
    virtual ~BLECharacteristicCallbacks() = default;
    virtual void onRead(BLECharacteristic *pCharacteristic) {
        (void)pCharacteristic;
    }
    virtual void onWrite(BLECharacteristic *pCharacteristic) {
        (void)pCharacteristic;
    }
};
 
class BLEServer {};
 
class BLEServerCallbacks {
  public:
    virtual ~BLEServerCallbacks() = default;
    virtual void onConnect(BLEServer *pServer) { (void)pServer; }
    virtual void onDisconnect(BLEServer *pServer) { (void)pServer; }
};
 
BEGIN_CS_NAMESPACE
 
class BLEMIDI {
  public:
    MOCK_METHOD(void, setServerCallbacks, (BLEServerCallbacks *));
    MOCK_METHOD(void, setCharacteristicsCallbacks,
                (BLECharacteristicCallbacks *));
    MOCK_METHOD(void, begin,
                (BLEServerCallbacks *, BLECharacteristicCallbacks *));
    MOCK_METHOD(void, notifyValue, (uint8_t * data, size_t len));
    MOCK_METHOD(std::string, getValue, ());
};
 
END_CS_NAMESPACE
 
#endif