web_server: Add cover calls to REST API (#999)

Add the GET and POST handler for cover components.  Also add covers to
the index page although the Open/Close buttons that are shown for covers
will need a few lines added to webserver-v1.js, without them they don't
do anything.

esphome/components/web_server/web_server.cpp

@@ -108,6 +108,12 @@ void WebServer::setup() {
       if (!obj->is_internal())
         client->send(this->text_sensor_json(obj, obj->state).c_str(), "state");
 #endif
+
+#ifdef USE_COVER
+    for (auto *obj : App.get_covers())
+      if (!obj->is_internal())
+        client->send(this->cover_json(obj).c_str(), "state");
+#endif
   });
 
 #ifdef USE_LOGGER
@@ -180,6 +186,11 @@ void WebServer::handle_index_request(AsyncWebServerRequest *request) {
     write_row(stream, obj, "text_sensor", "");
 #endif
 
+#ifdef USE_COVER
+  for (auto *obj : App.get_covers())
+    write_row(stream, obj, "cover", "<button>Open</button><button>Close</button>");
+#endif
+
   stream->print(F("</tbody></table><p>See <a href=\"https://esphome.io/web-api/index.html\">ESPHome Web API</a> for "
                   "REST API documentation.</p>"
                   "<h2>OTA Update</h2><form method=\"POST\" action=\"/update\" enctype=\"multipart/form-data\"><input "
@@ -495,6 +506,68 @@ std::string WebServer::light_json(light::LightState *obj) {
 }
 #endif
 
+#ifdef USE_COVER
+void WebServer::on_cover_update(cover::Cover *obj) {
+  if (obj->is_internal())
+    return;
+  this->events_.send(this->cover_json(obj).c_str(), "state");
+}
+void WebServer::handle_cover_request(AsyncWebServerRequest *request, UrlMatch match) {
+  for (cover::Cover *obj : App.get_covers()) {
+    if (obj->is_internal())
+      continue;
+    if (obj->get_object_id() != match.id)
+      continue;
+
+    if (request->method() == HTTP_GET) {
+      std::string data = this->cover_json(obj);
+      request->send(200, "text/json", data.c_str());
+      continue;
+    }
+
+    auto call = obj->make_call();
+    if (match.method == "open") {
+      call.set_command_open();
+    } else if (match.method == "close") {
+      call.set_command_close();
+    } else if (match.method == "stop") {
+      call.set_command_stop();
+    } else if (match.method != "set") {
+      request->send(404);
+      return;
+    }
+
+    auto traits = obj->get_traits();
+    if ((request->hasParam("position") && !traits.get_supports_position()) ||
+        (request->hasParam("tilt") && !traits.get_supports_tilt())) {
+      request->send(409);
+      return;
+    }
+
+    if (request->hasParam("position"))
+      call.set_position(request->getParam("position")->value().toFloat());
+    if (request->hasParam("tilt"))
+      call.set_tilt(request->getParam("tilt")->value().toFloat());
+
+    this->defer([call]() mutable { call.perform(); });
+    request->send(200);
+    return;
+  }
+  request->send(404);
+}
+std::string WebServer::cover_json(cover::Cover *obj) {
+  return json::build_json([obj](JsonObject &root) {
+    root["id"] = "cover-" + obj->get_object_id();
+    root["state"] = obj->is_fully_closed() ? "CLOSED" : "OPEN";
+    root["value"] = obj->position;
+    root["current_operation"] = cover::cover_operation_to_str(obj->current_operation);
+
+    if (obj->get_traits().get_supports_tilt())
+      root["tilt"] = obj->tilt;
+  });
+}
+#endif
+
 bool WebServer::canHandle(AsyncWebServerRequest *request) {
   if (request->url() == "/")
     return true;
@@ -542,6 +615,11 @@ bool WebServer::canHandle(AsyncWebServerRequest *request) {
     return true;
 #endif
 
+#ifdef USE_COVER
+  if ((request->method() == HTTP_POST || request->method() == HTTP_GET) && match.domain == "cover")
+    return true;
+#endif
+
   return false;
 }
 void WebServer::handleRequest(AsyncWebServerRequest *request) {
@@ -610,6 +688,13 @@ void WebServer::handleRequest(AsyncWebServerRequest *request) {
     return;
   }
 #endif
+
+#ifdef USE_COVER
+  if (match.domain == "cover") {
+    this->handle_cover_request(request, match);
+    return;
+  }
+#endif
 }
 
 bool WebServer::isRequestHandlerTrivial() { return false; }

esphome/components/web_server/web_server.h

@@ -144,6 +144,16 @@ class WebServer : public Controller, public Component, public AsyncWebHandler {
   std::string text_sensor_json(text_sensor::TextSensor *obj, const std::string &value);
 #endif
 
+#ifdef USE_COVER
+  void on_cover_update(cover::Cover *obj) override;
+
+  /// Handle a cover request under '/cover/<id>/<open/close/stop/set>'.
+  void handle_cover_request(AsyncWebServerRequest *request, UrlMatch match);
+
+  /// Dump the cover state as a JSON string.
+  std::string cover_json(cover::Cover *obj);
+#endif
+
   /// Override the web handler's canHandle method.
   bool canHandle(AsyncWebServerRequest *request) override;
   /// Override the web handler's handleRequest method.