text: /* ESP32 implementation of NetworkInterfaceAPI
   * Copyright (c) 2017 Renesas Electronics Corporation
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef ESP32_INTERFACE_AP_H
  #define ESP32_INTERFACE_AP_H
  
  #include "mbed.h"
  #include "ESP32Stack.h"
  
  
  /** ESP32Interface class
   *  Implementation of the NetworkStack for the ESP32
   */
  class ESP32InterfaceAP : public ESP32Stack, public WiFiInterface
  {
  public:
      /** ESP32InterfaceAP lifetime
       * @param en        EN pin  (If not used this pin, please set "NC")
       * @param io0       IO0 pin (If not used this pin, please set "NC")
       * @param tx        TX pin
       * @param rx        RX pin
       * @param debug     Enable debugging
       * @param rts       RTS pin
       * @param cts       CTS pin
       * @param baudrate  The baudrate of the serial port (default = 230400).
       */
      ESP32InterfaceAP(PinName en, PinName io0, PinName tx, PinName rx, bool debug = false,
                       PinName rts = NC, PinName cts = NC, int baudrate = 230400);
  
      /** ESP32InterfaceAP lifetime
       * @param tx        TX pin
       * @param rx        RX pin
       * @param debug     Enable debugging
       */
      ESP32InterfaceAP(PinName tx, PinName rx, bool debug = false);
  
      /** Set a static IP address
       *
       *  Configures this network interface to use a static IP address.
       *  Implicitly disables DHCP, which can be enabled in set_dhcp.
       *  Requires that the network is disconnected.
       *
       *  @param ip_address Null-terminated representation of the local IP address
       *  @param netmask    Null-terminated representation of the local network mask
       *  @param gateway    Null-terminated representation of the local gateway
       *  @return           0 on success, negative error code on failure
       */
      virtual nsapi_error_t set_network(
              const char *ip_address, const char *netmask, const char *gateway);
  
      /** Enable or disable DHCP on the network
       *
       *  Enables DHCP on connecting the network. Defaults to enabled unless
       *  a static IP address has been assigned. Requires that the network is
       *  disconnected.
       *
       *  @param dhcp     True to enable DHCP
       *  @return         0 on success, negative error code on failure
       */
      virtual nsapi_error_t set_dhcp(bool dhcp);
  
      /** Start the interface
       *
       *  Attempts to connect to a WiFi network. Requires ssid and passphrase to be set.
       *  If passphrase is invalid, NSAPI_ERROR_AUTH_ERROR is returned.
       *
       *  @return         0 on success, negative error code on failure
       */
      virtual int connect();
  
      /** Start the interface
       *
       *  Attempts to connect to a WiFi network.
       *
       *  @param ssid      Name of the network to connect to
       *  @param pass      Security passphrase to connect to the network
       *  @param security  Type of encryption for connection (Default: NSAPI_SECURITY_NONE)
       *  @param channel   This parameter is not supported, setting it to anything else than 0 will result in NSAPI_ERROR_UNSUPPORTED
       *  @return          0 on success, or error code on failure
       */
      virtual int connect(const char *ssid, const char *pass, nsapi_security_t security = NSAPI_SECURITY_NONE,
                                    uint8_t channel = 0);
  
      /** Set the WiFi network credentials
       *
       *  @param ssid      Name of the network to connect to
       *  @param pass      Security passphrase to connect to the network
       *  @param security  Type of encryption for connection
       *                   (defaults to NSAPI_SECURITY_NONE)
       *  @return          0 on success, or error code on failure
       */
      virtual int set_credentials(const char *ssid, const char *pass, nsapi_security_t security = NSAPI_SECURITY_NONE);
  
      /** Set the WiFi network channel - NOT SUPPORTED
       *
       * This function is not supported and will return NSAPI_ERROR_UNSUPPORTED
       *
       *  @param channel   Channel on which the connection is to be made, or 0 for any (Default: 0)
       *  @return          Not supported, returns NSAPI_ERROR_UNSUPPORTED
       */
      virtual int set_channel(uint8_t channel);
  
      /** Stop the interface
       *  @return             0 on success, negative on failure
       */
      virtual int disconnect();
  
      /** Get the internally stored IP address
       *  @return             IP address of the interface or null if not yet connected
       */
      virtual const char *get_ip_address();
  
      /** Get the internally stored MAC address
       *  @return             MAC address of the interface
       */
      virtual const char *get_mac_address();
  
       /** Get the local gateway
       *
       *  @return         Null-terminated representation of the local gateway
       *                  or null if no network mask has been recieved
       */
      virtual const char *get_gateway();
  
      /** Get the local network mask
       *
       *  @return         Null-terminated representation of the local network mask
       *                  or null if no network mask has been recieved
       */
      virtual const char *get_netmask();
  
      /** Gets the current radio signal strength for active connection
       *
       * @return          Connection strength in dBm (negative value)
       */
      virtual int8_t get_rssi();
  
      /** Scan for available networks
       *
       * This function will block.
       *
       * @param  ap       Pointer to allocated array to store discovered AP
       * @param  count    Size of allocated @a res array, or 0 to only count available AP
       * @param  timeout  Timeout in milliseconds; 0 for no timeout (Default: 0)
       * @return          Number of entries in @a, or if @a count was 0 number of available networks, negative on error
       *                  see @a nsapi_error
       */
      virtual int scan(WiFiAccessPoint *res, unsigned count);
  
      /** Translates a hostname to an IP address with specific version
       *
       *  The hostname may be either a domain name or an IP address. If the
       *  hostname is an IP address, no network transactions will be performed.
       *
       *  If no stack-specific DNS resolution is provided, the hostname
       *  will be resolve using a UDP socket on the stack.
       *
       *  @param address  Destination for the host SocketAddress
       *  @param host     Hostname to resolve
       *  @param version  IP version of address to resolve, NSAPI_UNSPEC indicates
       *                  version is chosen by the stack (defaults to NSAPI_UNSPEC)
       *  @return         0 on success, negative error code on failure
       */
      using NetworkInterface::gethostbyname;
  
      /** Add a domain name server to list of servers to query
       *
       *  @param addr     Destination for the host address
       *  @return         0 on success, negative error code on failure
       */
      using NetworkInterface::add_dns_server;
  
      /** Register callback for status reporting
       *
       *  The specified status callback function will be called on status changes
       *  on the network. The parameters on the callback are the event type and
       *  event-type dependent reason parameter.
       *
       *  In ESP32 the callback will be called when processing OOB-messages via
       *  AT-parser. Do NOT call any ESP8266Interface -functions or do extensive
       *  processing in the callback.
       *
       *  @param status_cb The callback for status changes
       */
      virtual void attach(mbed::Callback<void(nsapi_event_t, intptr_t)> status_cb);
  
      /** Get the connection status
       *
       *  @return         The connection status according to ConnectionStatusType
       */
      virtual nsapi_connection_status_t get_connection_status() const;
  
  
      /** Provide access to the NetworkStack object
       *
       *  @return The underlying NetworkStack object
       */
      virtual NetworkStack *get_stack()
      {
          return this;
      }
  
  private:
      bool _dhcp;
      uint8_t _own_ch;
      char _own_ssid[33]; /* 32 is what 802.11 defines as longest possible name; +1 for the \0 */
      char _own_pass[64]; /* The longest allowed passphrase */
      nsapi_security_t _own_sec;
      char _ip_address[NSAPI_IPv6_SIZE];
      char _netmask[NSAPI_IPv4_SIZE];
      char _gateway[NSAPI_IPv4_SIZE];
      nsapi_connection_status_t _connection_status;
      Callback<void(nsapi_event_t, intptr_t)> _connection_status_cb;
  };
  
  #endif
  