feat: implement HttpHandler and WifiHandler classes for HTTP client management

main/network/wifi_handler.h

@@ -0,0 +1,54 @@
+#pragma once
+#include "io/io.h"
+#include "esp_wifi.h"
+#include "freertos/event_groups.h"
+
+#define WIFI_CONNECTED_BIT (1 << 0)
+
+class WifiHandler {
+public:
+  WifiHandler(
+    // this handler is used to store/retrieve WiFi credentials
+    // should have a unique namespace for WiFi credentials
+    // it will be owned by WifiHandler and deleted in its destructor
+    KVStorageHandler* kvs
+  );
+  ~WifiHandler();
+
+  // move semantics
+  WifiHandler(WifiHandler&& other) noexcept;
+
+  void init();
+  esp_err_t connect(const char* ssid, const char* password);
+  esp_err_t connect(const char* ssid); // connect using stored password
+  esp_err_t reconnect(); // reconnect to current SSID
+  void disconnect();
+  EventBits_t wait_for_connection(TickType_t ticks_to_wait);
+  // returns list of available networks, caller is responsible for freeing the returned memory
+  // returns nullptr if scan failed
+  esp_err_t scan_networks(
+    wifi_ap_record_t*& ap_records,
+    uint16_t& ap_count
+  );
+
+  static void wifi_event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data);
+
+private:
+  // prevent copying
+  WifiHandler(const WifiHandler&) = delete;
+  WifiHandler& operator=(const WifiHandler&) = delete;
+
+  char* build_password_key(const char* ssid);
+  void get_wifi_credentials(char*& ssid, char*& password);
+
+  bool initialized = false;
+  KVStorageHandler* kvs = nullptr;
+  EventGroupHandle_t s_wifi_event_group = 0;
+  SemaphoreHandle_t scan_mutex = nullptr;
+  SemaphoreHandle_t connection_mutex = nullptr;
+  // current connected / preferred SSID
+  char* current_ssid = nullptr;
+  // prevent auto-reconnect on expected disconnection, e.g. when user calls disconnect()
+  // should be reset to false after connect()
+  bool expect_disconnected = false;
+};