api: Implement OPTIONS request to allow CORS preflight checks to succeed

main/api.c

@@ -174,6 +174,21 @@ static const httpd_uri_t wakeup_delete = {
     .handler   = wakeup_delete_handler
 };
 
+static esp_err_t wakeup_options_handler(httpd_req_t *req) {
+	httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
+	httpd_resp_set_hdr(req, "Access-Control-Allow-Methods", "GET, PUT, DELETE, OPTIONS");
+	httpd_resp_set_hdr(req, "Access-Control-Max-Age", "86400");
+	httpd_resp_set_hdr(req, "Access-Control-Allow-Headers", "Content-Type");
+	httpd_resp_sendstr(req, "");
+	return ESP_OK;
+}
+
+static const httpd_uri_t wakeup_options = {
+    .uri       = "/v1/wakeup/*",
+    .method    = HTTP_OPTIONS,
+    .handler   = wakeup_options_handler
+};
+
 
 httpd_handle_t start_webserver(TaskHandle_t* task_handle) {
    httpd_handle_t server;
@@ -190,6 +205,7 @@ httpd_handle_t start_webserver(TaskHandle_t* task_handle) {
       httpd_register_uri_handler(server, &wakeup_get);
      	httpd_register_uri_handler(server, &wakeup_put);
 		httpd_register_uri_handler(server, &wakeup_delete);
+		httpd_register_uri_handler(server, &wakeup_options);
       return server;
     }