FrameAssistant/tests/FakeMqttClient.h

#pragma once

#include <QList>
#include <QStringList>

#include "mqtt/MqttClient.h"

// MqttClient for unit tests: records what is published and subscribed;
// the test drives the connection state and incoming messages.
class FakeMqttClient : public MqttClient {
  Q_OBJECT
 public:
  struct Message {
    QString topic;
    QByteArray payload;
    bool retain = false;
  };

  using MqttClient::MqttClient;

  void connectToBroker() override { ++connectCalls; }
  bool disconnectFromBroker(int) override {
    setState(State::Disconnected);
    return true;
  }
  bool publish(const QString& topic, const QByteArray& payload,
               bool retain) override {
    if (m_state != State::Connected) return false;
    published.append({topic, payload, retain});
    return true;
  }
  bool subscribe(const QString& topic) override {
    if (m_state != State::Connected) return false;
    subscriptions.append(topic);
    return true;
  }
  bool waitForPublished(int) override { return true; }
  State state() const override { return m_state; }

  // Test side.
  void setState(State state, const QString& error = {}) {
    m_state = state;
    emit connectionChanged(state, error);
  }
  void deliver(const QString& topic, const QByteArray& payload) {
    emit messageReceived(topic, payload);
  }
  // The messages published to `topic`, oldest first.
  QList<Message> to(const QString& topic) const {
    QList<Message> result;
    for (const Message& message : published)
      if (message.topic == topic) result.append(message);
    return result;
  }

  QList<Message> published;
  QStringList subscriptions;
  int connectCalls = 0;

 private:
  State m_state = State::Disconnected;
};