Add select entities and implement template select (#2067)

Co-authored-by: Otto Winter <otto@otto-winter.com>

esphome/components/select/select.cpp

@@ -0,0 +1,43 @@
+#include "select.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace select {
+
+static const char *const TAG = "select";
+
+void SelectCall::perform() {
+  ESP_LOGD(TAG, "'%s' - Setting", this->parent_->get_name().c_str());
+  if (!this->option_.has_value()) {
+    ESP_LOGW(TAG, "No value set for SelectCall");
+    return;
+  }
+
+  const auto &traits = this->parent_->traits;
+  auto value = *this->option_;
+  auto options = traits.get_options();
+
+  if (std::find(options.begin(), options.end(), value) == options.end()) {
+    ESP_LOGW(TAG, "  Option %s is not a valid option.", value.c_str());
+    return;
+  }
+
+  ESP_LOGD(TAG, "  Option: %s", (*this->option_).c_str());
+  this->parent_->control(*this->option_);
+}
+
+void Select::publish_state(const std::string &state) {
+  this->has_state_ = true;
+  this->state = state;
+  ESP_LOGD(TAG, "'%s': Sending state %s", this->get_name().c_str(), state.c_str());
+  this->state_callback_.call(state);
+}
+
+void Select::add_on_state_callback(std::function<void(std::string)> &&callback) {
+  this->state_callback_.add(std::move(callback));
+}
+
+uint32_t Select::hash_base() { return 2812997003UL; }
+
+}  // namespace select
+}  // namespace esphome