Event entity support (#6451)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/mqtt/mqtt_event.cpp

@@ -0,0 +1,54 @@
+#include "mqtt_event.h"
+#include "esphome/core/log.h"
+
+#include "mqtt_const.h"
+
+#ifdef USE_MQTT
+#ifdef USE_EVENT
+
+namespace esphome {
+namespace mqtt {
+
+static const char *const TAG = "mqtt.event";
+
+using namespace esphome::event;
+
+MQTTEventComponent::MQTTEventComponent(event::Event *event) : event_(event) {}
+
+void MQTTEventComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
+  JsonArray event_types = root.createNestedArray(MQTT_EVENT_TYPES);
+  for (const auto &event_type : this->event_->get_event_types())
+    event_types.add(event_type);
+
+  if (!this->event_->get_device_class().empty())
+    root[MQTT_DEVICE_CLASS] = this->event_->get_device_class();
+
+  config.command_topic = false;
+}
+
+void MQTTEventComponent::setup() {
+  this->event_->add_on_event_callback([this](const std::string &event_type) { this->publish_event_(event_type); });
+}
+
+void MQTTEventComponent::dump_config() {
+  ESP_LOGCONFIG(TAG, "MQTT Event '%s': ", this->event_->get_name().c_str());
+  ESP_LOGCONFIG(TAG, "Event Types: ");
+  for (const auto &event_type : this->event_->get_event_types()) {
+    ESP_LOGCONFIG(TAG, "- %s", event_type.c_str());
+  }
+  LOG_MQTT_COMPONENT(true, true);
+}
+
+bool MQTTEventComponent::publish_event_(const std::string &event_type) {
+  return this->publish_json(this->get_state_topic_(),
+                            [event_type](JsonObject root) { root[MQTT_EVENT_TYPE] = event_type; });
+}
+
+std::string MQTTEventComponent::component_type() const { return "event"; }
+const EntityBase *MQTTEventComponent::get_entity() const { return this->event_; }
+
+}  // namespace mqtt
+}  // namespace esphome
+
+#endif
+#endif  // USE_MQTT