feat: enhance UDPClient initialization with local port binding and add WebServerHandler for HTTP server management

main/network/udp_client.cpp

@@ -19,7 +19,7 @@ UDPClient::~UDPClient() {
     close();
 }
 
-esp_err_t UDPClient::init() {
+esp_err_t UDPClient::init(uint16_t local_port) {
     if (initialized_) {
         ESP_LOGW(TAG, "Already initialized");
         return ESP_OK;
@@ -31,6 +31,23 @@ esp_err_t UDPClient::init() {
         return ESP_FAIL;
     }
 
+    // Bind to local port if specified
+    if (local_port > 0) {
+        struct sockaddr_in local_addr;
+        memset(&local_addr, 0, sizeof(local_addr));
+        local_addr.sin_family = AF_INET;
+        local_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+        local_addr.sin_port = htons(local_port);
+
+        if (bind(sock_fd_, (struct sockaddr*)&local_addr, sizeof(local_addr)) < 0) {
+            ESP_LOGE(TAG, "Failed to bind to port %u: errno %d", local_port, errno);
+            ::close(sock_fd_);
+            sock_fd_ = -1;
+            return ESP_FAIL;
+        }
+        ESP_LOGI(TAG, "Bound to local port %u", local_port);
+    }
+
     // Set socket to non-blocking mode
     esp_err_t err = set_nonblocking();
     if (err != ESP_OK) {

main/network/udp_client.h

@@ -19,9 +19,10 @@ public:
 
     /**
      * @brief Initialize UDP socket
+     * @param local_port Local port to bind to (0 = system assigns port)
      * @return ESP_OK on success, error code otherwise
      */
-    esp_err_t init();
+    esp_err_t init(uint16_t local_port = 0);
 
     /**
      * @brief Configure remote endpoint

main/network/web_server_handler.cpp

@@ -0,0 +1,113 @@
+#include "web_server_handler.h"
+#include "esp_log.h"
+#include <cstring>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <unistd.h>
+
+static const char* TAG = "WebServerHandler";
+
+WebServerHandler::WebServerHandler() { }
+
+WebServerHandler::~WebServerHandler() {
+  stop();
+}
+
+uint16_t WebServerHandler::start(const std::string& auth_key, uint16_t base_port) {
+  if (server_ != nullptr) {
+    ESP_LOGW(TAG, "Server already running on port %d", current_port_);
+    return current_port_;
+  }
+
+  auth_key_ = auth_key;
+
+  // Try to find a free port
+  uint16_t port = base_port;
+  const uint16_t max_attempts = 100;
+
+  for (uint16_t attempt = 0; attempt < max_attempts; attempt++) {
+    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
+    config.server_port = port;
+    config.ctrl_port = port + 1000; // Control port
+    config.max_open_sockets = 7;
+    config.lru_purge_enable = true;
+
+    esp_err_t err = httpd_start(&server_, &config);
+
+    if (err == ESP_OK) {
+      current_port_ = port;
+      ESP_LOGI(TAG, "Web server started successfully on port %d", current_port_);
+      return current_port_;
+    } else if (err == ESP_ERR_HTTPD_ALLOC_MEM) {
+      ESP_LOGE(TAG, "Failed to allocate memory for web server");
+      return 0;
+    } else {
+      // Port likely in use, try next port
+      ESP_LOGD(TAG, "Port %d in use, trying next port", port);
+      port++;
+    }
+  }
+
+  ESP_LOGE(TAG, "Failed to find free port after %d attempts", max_attempts);
+  return 0;
+}
+
+esp_err_t WebServerHandler::stop() {
+  if (server_ == nullptr) {
+    return ESP_OK;
+  }
+
+  esp_err_t err = httpd_stop(server_);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to stop web server: %s", esp_err_to_name(err));
+    return err;
+  }
+
+  server_ = nullptr;
+  current_port_ = 0;
+  auth_key_.clear();
+
+  ESP_LOGI(TAG, "Web server stopped");
+  return ESP_OK;
+}
+
+esp_err_t WebServerHandler::register_uri_handler(const httpd_uri_t* uri_handler) {
+  if (server_ == nullptr) {
+    ESP_LOGE(TAG, "Server not running, cannot register URI handler");
+    return ESP_ERR_INVALID_STATE;
+  }
+
+  esp_err_t err = httpd_register_uri_handler(server_, uri_handler);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Failed to register URI handler: %s", esp_err_to_name(err));
+    return err;
+  }
+
+  return ESP_OK;
+}
+
+bool WebServerHandler::validate_auth(const char* query_string) const {
+  if (!query_string || auth_key_.empty()) {
+    return false;
+  }
+
+  // Look for "auth=<key>" in query string
+  const char* auth_param = strstr(query_string, "auth=");
+  if (!auth_param) {
+    return false;
+  }
+
+  // Skip "auth="
+  auth_param += 5;
+
+  // Find end of auth value (& or end of string)
+  const char* end = strchr(auth_param, '&');
+  size_t auth_len = end ? (size_t)(end - auth_param) : strlen(auth_param);
+
+  // Compare with stored auth key
+  if (auth_len != auth_key_.length()) {
+    return false;
+  }
+
+  return strncmp(auth_param, auth_key_.c_str(), auth_len) == 0;
+}

main/network/web_server_handler.h

@@ -0,0 +1,42 @@
+#pragma once
+#include "esp_http_server.h"
+#include "esp_err.h"
+#include <string>
+#include <functional>
+
+class WebServerHandler {
+public:
+  WebServerHandler();
+  ~WebServerHandler();
+
+  // Start web server, finds a free port starting from base_port
+  // Returns the actual port used, or 0 on failure
+  uint16_t start(const std::string& auth_key, uint16_t base_port = 8080);
+
+  // Stop web server
+  esp_err_t stop();
+
+  // Check if server is running
+  bool is_running() const { return server_ != nullptr; }
+
+  // Get the current port
+  uint16_t get_port() const { return current_port_; }
+
+  // Get the auth key
+  std::string get_auth_key() const { return auth_key_; }
+
+  // Register a URI handler
+  esp_err_t register_uri_handler(const httpd_uri_t* uri_handler);
+
+  // Validate auth key from query string
+  bool validate_auth(const char* query_string) const;
+
+private:
+  // Prevent copying
+  WebServerHandler(const WebServerHandler&) = delete;
+  WebServerHandler& operator=(const WebServerHandler&) = delete;
+
+  httpd_handle_t server_ = nullptr;
+  uint16_t current_port_ = 0;
+  std::string auth_key_;
+};

main/network/wifi_handler.cpp

@@ -539,3 +539,23 @@ EventBits_t WifiHandler::wait_for_connection(TickType_t ticks_to_wait) {
     ticks_to_wait
   );
 }
+
+std::string WifiHandler::get_current_ip() const {
+  esp_netif_t* netif = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
+  if (!netif) {
+    ESP_LOGW(TAG, "Failed to get netif handle");
+    return "";
+  }
+
+  esp_netif_ip_info_t ip_info;
+  esp_err_t err = esp_netif_get_ip_info(netif, &ip_info);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "Failed to get IP info: %s", esp_err_to_name(err));
+    return "";
+  }
+
+  // Convert IP address to string
+  char ip_str[16];
+  snprintf(ip_str, sizeof(ip_str), IPSTR, IP2STR(&ip_info.ip));
+  return std::string(ip_str);
+}

main/network/wifi_handler.h

@@ -31,6 +31,9 @@ public:
     uint16_t& ap_count
   );
 
+  // Get current IP address (empty string if not connected)
+  std::string get_current_ip() const;
+
   static void wifi_event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data);
 
 private: