// HaDevice with a fake MQTT client (docs/DESIGN.md, D31, D32): discovery
// payload, what is published after a connect, reconnect, HA's birth message,
// last will, removal.

#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QTest>

#include "FakeMqttClient.h"
#include "ha/HaDevice.h"
#include "ha/HaSensor.h"

namespace {

using State = MqttClient::State;

HaDevice::Info info() {
  return {.name = QStringLiteral("Wohnzimmer Frame"),
          .id = QStringLiteral("wohnzimmer_frame"),
          .softwareVersion = QStringLiteral("1.2.3")};
}

HaEntity::Description uptime() {
  return {.id = QStringLiteral("uptime"),
          .name = QStringLiteral("Uptime"),
          .unit = QStringLiteral("s"),
          .throttleMs = 0};
}

const QString kBase = QStringLiteral("frameassistant/wohnzimmer_frame");
const QString kDiscovery =
    QStringLiteral("homeassistant/device/wohnzimmer_frame/config");

}  // namespace

class TestHaDevice : public QObject {
  Q_OBJECT

 private slots:
  void topics() {
    FakeMqttClient client;
    const HaDevice device(info(), &client);
    QCOMPARE(device.baseTopic(), kBase);
    QCOMPARE(device.discoveryTopic(), kDiscovery);
    QCOMPARE(device.availabilityTopic(), kBase + "/availability");
  }

  void discoveryPrefixFromInfo() {
    FakeMqttClient client;
    HaDevice::Info i = info();
    i.discoveryPrefix = QStringLiteral("ha");
    HaDevice device(i, &client);
    QCOMPARE(device.discoveryTopic(),
             QStringLiteral("ha/device/wohnzimmer_frame/config"));
    client.setState(State::Connected);
    QCOMPARE(client.subscriptions, QStringList{QStringLiteral("ha/status")});
  }

  void lastWill() {
    const MqttClient::Will will =
        HaDevice::lastWill(QStringLiteral("wohnzimmer_frame"));
    QCOMPARE(will.topic, kBase + "/availability");
    QCOMPARE(will.payload, QByteArray("offline"));
    QVERIFY(will.retain);
  }

  void discoveryPayload() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.addSensor(uptime());
    const QJsonObject payload =
        QJsonDocument::fromJson(device.discoveryPayload()).object();
    const QJsonObject dev = payload.value(QStringLiteral("dev")).toObject();
    QCOMPARE(dev.value(QStringLiteral("ids")).toArray(),
             QJsonArray{QStringLiteral("frameassistant_wohnzimmer_frame")});
    QCOMPARE(dev.value(QStringLiteral("name")).toString(),
             QStringLiteral("Wohnzimmer Frame"));
    QCOMPARE(dev.value(QStringLiteral("sw")).toString(),
             QStringLiteral("1.2.3"));
    const QJsonObject origin = payload.value(QStringLiteral("o")).toObject();
    QCOMPARE(origin.value(QStringLiteral("name")).toString(),
             QStringLiteral("FrameAssistant"));
    QCOMPARE(payload.value(QStringLiteral("~")).toString(), kBase);
    QCOMPARE(payload.value(QStringLiteral("qos")).toInt(), 1);
    const QJsonObject components =
        payload.value(QStringLiteral("cmps")).toObject();
    QCOMPARE(components.keys(), QStringList{QStringLiteral("uptime")});
    QCOMPARE(components.value(QStringLiteral("uptime"))
                 .toObject()
                 .value(QStringLiteral("uniq_id"))
                 .toString(),
             QStringLiteral("frameassistant_wohnzimmer_frame_uptime"));
  }

  // After a connect: subscription, then discovery, device availability,
  // state and entity availability, all retained.
  void publishesAllAfterConnect() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.addSensor(uptime())->setValue(7);
    QVERIFY(client.published.isEmpty());  // not connected yet
    client.setState(State::Connected);
    QCOMPARE(client.subscriptions,
             QStringList{QStringLiteral("homeassistant/status")});
    QStringList topics;
    for (const FakeMqttClient::Message& m : client.published) {
      topics.append(m.topic);
      QVERIFY2(m.retain, qPrintable(m.topic));
    }
    QCOMPARE(topics, (QStringList{kDiscovery, kBase + "/availability",
                                  kBase + "/uptime/state",
                                  kBase + "/uptime/availability"}));
    QCOMPARE(client.published[0].payload, device.discoveryPayload());
    QCOMPARE(client.published[1].payload, QByteArray("online"));
    QCOMPARE(client.published[2].payload, QByteArray("7"));
    QCOMPARE(client.published[3].payload, QByteArray("online"));
  }

  // SEN-15: an entity without a value is published as unavailable.
  void entityWithoutValueUnavailable() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.addSensor(uptime());
    client.setState(State::Connected);
    QVERIFY(client.to(kBase + "/uptime/state").isEmpty());
    const QList<FakeMqttClient::Message> availability =
        client.to(kBase + "/uptime/availability");
    QCOMPARE(availability.size(), 1);
    QCOMPARE(availability.first().payload, QByteArray("offline"));
  }

  void valueChangesPublishedWhileConnected() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    HaSensor* sensor = device.addSensor(uptime());
    client.setState(State::Connected);
    client.published.clear();
    sensor->setValue(1);
    QCOMPARE(client.published.size(), 2);
    QCOMPARE(client.published[0].topic, kBase + "/uptime/state");
    QCOMPARE(client.published[0].payload, QByteArray("1"));
    QVERIFY(client.published[0].retain);
    QCOMPARE(client.published[1].topic, kBase + "/uptime/availability");
    QCOMPARE(client.published[1].payload, QByteArray("online"));
    sensor->setValue(2);
    QCOMPARE(client.published.size(), 3);
    QCOMPARE(client.published[2].payload, QByteArray("2"));
    sensor->clearValue();
    QCOMPARE(client.published.size(), 4);
    QCOMPARE(client.published[3].topic, kBase + "/uptime/availability");
    QCOMPARE(client.published[3].payload, QByteArray("offline"));
  }

  // CON-4: nothing is buffered; after a reconnect everything is current.
  void reconnectRepublishesCurrentState() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    HaSensor* sensor = device.addSensor(uptime());
    sensor->setValue(1);
    client.setState(State::Connected);
    client.setState(State::Disconnected, QStringLiteral("lost"));
    client.published.clear();
    client.subscriptions.clear();
    sensor->setValue(2);
    sensor->setValue(3);
    QVERIFY(client.published.isEmpty());
    client.setState(State::Connected);
    QCOMPARE(client.subscriptions.size(), 1);
    const QList<FakeMqttClient::Message> states =
        client.to(kBase + "/uptime/state");
    QCOMPARE(states.size(), 1);
    QCOMPARE(states.first().payload, QByteArray("3"));
    QCOMPARE(client.to(kDiscovery).size(), 1);
  }

  void birthMessageRepublishesAfterDelay() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.setBirthDelay(50, 100);
    device.addSensor(uptime())->setValue(1);
    client.setState(State::Connected);
    client.published.clear();
    client.deliver(QStringLiteral("homeassistant/status"), "online");
    QVERIFY(client.published.isEmpty());  // not at once
    QTRY_COMPARE_WITH_TIMEOUT(client.to(kDiscovery).size(), 1, 2000);
    QCOMPARE(client.to(kBase + "/uptime/state").size(), 1);
  }

  void otherMessagesIgnored() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.setBirthDelay(0, 0);
    client.setState(State::Connected);
    client.published.clear();
    client.deliver(QStringLiteral("homeassistant/status"), "offline");
    client.deliver(QStringLiteral("other/status"), "online");
    QTest::qWait(50);
    QVERIFY(client.published.isEmpty());
  }

  void disconnectCancelsPendingBirthRepublish() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.setBirthDelay(50, 50);
    client.setState(State::Connected);
    client.deliver(QStringLiteral("homeassistant/status"), "online");
    client.setState(State::Disconnected);
    client.published.clear();
    QTest::qWait(150);
    QVERIFY(client.published.isEmpty());
  }

  // --ha-remove: empty retained payloads on every topic, discovery first.
  void removeFromHa() {
    FakeMqttClient client;
    HaDevice device(info(), &client);
    device.addSensor(uptime());
    QVERIFY(!device.removeFromHa());  // not connected
    client.setState(State::Connected);
    client.published.clear();
    QVERIFY(device.removeFromHa());
    QStringList topics;
    for (const FakeMqttClient::Message& m : client.published) {
      topics.append(m.topic);
      QVERIFY(m.payload.isEmpty());
      QVERIFY(m.retain);
    }
    QCOMPARE(topics, (QStringList{kDiscovery, kBase + "/availability",
                                  kBase + "/uptime/state",
                                  kBase + "/uptime/availability"}));
  }
};

QTEST_GUILESS_MAIN(TestHaDevice)
#include "tst_hadevice.moc"