feat: implement HttpHandler and WifiHandler classes for HTTP client management

main/network/http_handler.h

@@ -0,0 +1,55 @@
+#pragma once
+#include <memory>
+#include "esp_http_client.h"
+#include "network/wifi_handler.h"
+
+// forward declare NetworkHandler to avoid circular include with network.h
+class NetworkHandler;
+
+// default config values for esp_http_client_config_t
+// disable Wmissing-field-initializers warning for these structs
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+static const inline esp_http_client_config_t DEFAULT_HTTP_CLIENT_CONFIG = {
+  .timeout_ms = 10000,
+};
+
+static const inline esp_http_client_config_t DEFAULT_HTTP_CLIENT_CONFIG_HTTPS = {
+  .transport_type = HTTP_TRANSPORT_OVER_SSL,
+  //
+  .use_global_ca_store = true,
+  .skip_cert_common_name_check = false,
+};
+#pragma GCC diagnostic pop
+
+// esp http client wrapper with automatic initialization and cleanup
+class HttpHandler {
+public:
+  ~HttpHandler();
+
+  esp_err_t set_method(esp_http_client_method_t method);
+  esp_err_t set_header(const char* header, const char* value);
+  esp_err_t set_post_field(const char* field, size_t len);
+  //
+  esp_err_t perform_request();
+  // buffer is allocated inside the method, caller must free it
+  void get_body(
+    char*& buffer,
+    int& total_len
+  );
+
+
+  // only NetworkHandler can create HttpHandler instances
+  friend class NetworkHandler;
+  // disable copy constructor and assignment operator
+  HttpHandler(const HttpHandler&) = delete;
+  HttpHandler& operator=(const HttpHandler&) = delete;
+
+private:
+  // private constructor, only NetworkHandler can create instances
+  HttpHandler(const esp_http_client_config_t&& config, WifiHandler* wifiHandler);
+
+  esp_http_client_handle_t client;
+  // backreference to WifiHandler to ensure WiFi is connected, DO NOT DELETE
+  WifiHandler* wifiHandler;
+};