****************************************
:mod:`network` --- network configuration
****************************************

.. include:: ../templates/unsupported_in_circuitpython.inc

.. module:: network
   :synopsis: network configuration

This module provides network drivers and routing configuration. To use this
module, a MicroPython variant/build with network capabilities must be installed.
Network drivers for specific hardware are available within this module and are
used to configure hardware network interface(s). Network services provided
by configured interfaces are then available for use via the :mod:`usocket`
module.

For example::

    # connect/ show IP config a specific network interface
    # see below for examples of specific drivers
    import network
    import utime
    nic = network.Driver(...)
    if not nic.isconnected():
        nic.connect()
        print("Waiting for connection...")
        while not nic.isconnected():
            utime.sleep(1)
    print(nic.ifconfig())

    # now use usocket as usual
    import usocket as socket
    addr = socket.getaddrinfo('micropython.org', 80)[0][-1]
    s = socket.socket()
    s.connect(addr)
    s.send(b'GET / HTTP/1.1\r\nHost: micropython.org\r\n\r\n')
    data = s.recv(1000)
    s.close()

Common network adapter interface
================================

This section describes an (implied) abstract base class for all network
interface classes implemented by ``MicroPython ports <MicroPython port>``
for different hardware. This means that MicroPython does not actually
provide ``AbstractNIC`` class, but any actual NIC class, as described
in the following sections, implements methods as described here.

.. class:: AbstractNIC(id=None, ...)

Instantiate a network interface object. Parameters are network interface
dependent. If there are more than one interface of the same type, the first
parameter should be `id`.

    .. method:: active([is_active])

        Activate ("up") or deactivate ("down") the network interface, if
        a boolean argument is passed. Otherwise, query current state if
        no argument is provided. Most other methods require an active
        interface (behavior of calling them on inactive interface is
        undefined).

    .. method:: connect([service_id, key=None, \*, ...])

       Connect the interface to a network. This method is optional, and
       available only for interfaces which are not "always connected".
       If no parameters are given, connect to the default (or the only)
       service. If a single parameter is given, it is the primary identifier
       of a service to connect to. It may be accompanied by a key
       (password) required to access said service. There can be further
       arbitrary keyword-only parameters, depending on the networking medium
       type and/or particular device. Parameters can be used to: a)
       specify alternative service identifer types; b) provide additional
       connection parameters. For various medium types, there are different
       sets of predefined/recommended parameters, among them:

       * WiFi: *bssid* keyword to connect to a specific BSSID (MAC address)

    .. method:: disconnect()

       Disconnect from network.

    .. method:: isconnected()

       Returns ``True`` if connected to network, otherwise returns ``False``.

    .. method:: scan(\*, ...)

       Scan for the available network services/connections. Returns a
       list of tuples with discovered service parameters. For various
       network media, there are different variants of predefined/
       recommended tuple formats, among them:

       * WiFi: (ssid, bssid, channel, RSSI, authmode, hidden). There
         may be further fields, specific to a particular device.

       The function may accept additional keyword arguments to filter scan
       results (e.g. scan for a particular service, on a particular channel,
       for services of a particular set, etc.), and to affect scan
       duration and other parameters. Where possible, parameter names
       should match those in connect().

    .. method:: status()

       Return detailed status of the interface, values are dependent
       on the network medium/technology.

    .. method:: ifconfig([(ip, subnet, gateway, dns)])

       Get/set IP-level network interface parameters: IP address, subnet mask,
       gateway and DNS server. When called with no arguments, this method returns
       a 4-tuple with the above information. To set the above values, pass a
       4-tuple with the required information.  For example::

        nic.ifconfig(('192.168.0.4', '255.255.255.0', '192.168.0.1', '8.8.8.8'))

    .. method:: config('param')
                config(param=value, ...)

       Get or set general network interface parameters. These methods allow to work
       with additional parameters beyond standard IP configuration (as dealt with by
       `ifconfig()`). These include network-specific and hardware-specific
       parameters and status values. For setting parameters, the keyword argument
       syntax should be used, and multiple parameters can be set at once. For
       querying, a parameter name should be quoted as a string, and only one
       parameter can be queried at a time::

        # Set WiFi access point name (formally known as ESSID) and WiFi channel
        ap.config(essid='My AP', channel=11)
        # Query params one by one
        print(ap.config('essid'))
        print(ap.config('channel'))
        # Extended status information also available this way
        print(sta.config('rssi'))

.. _network.WLAN:

Functions
=========

.. function:: phy_mode([mode])

    Get or set the PHY mode.

    If the *mode* parameter is provided, sets the mode to its value. If
    the function is called without parameters, returns the current mode.

    The possible modes are defined as constants:
        * ``MODE_11B`` -- IEEE 802.11b,
        * ``MODE_11G`` -- IEEE 802.11g,
        * ``MODE_11N`` -- IEEE 802.11n.

class WLAN
==========

This class provides a driver for WiFi network processor in the ESP8266.  Example usage::

    import network
    # enable station interface and connect to WiFi access point
    nic = network.WLAN(network.STA_IF)
    nic.active(True)
    nic.connect('your-ssid', 'your-password')
    # now use sockets as usual

Constructors
------------
.. class:: WLAN(interface_id)

Create a WLAN network interface object. Supported interfaces are
``network.STA_IF`` (station aka client, connects to upstream WiFi access
points) and ``network.AP_IF`` (access point, allows other WiFi clients to
connect). Availability of the methods below depends on interface type.
For example, only STA interface may `connect()` to an access point.

Methods
-------

.. method:: wlan.active([is_active])

    Activate ("up") or deactivate ("down") network interface, if boolean
    argument is passed. Otherwise, query current state if no argument is
    provided. Most other methods require active interface.

.. method:: wlan.connect(ssid=None, password=None, \*, bssid=None)

    Connect to the specified wireless network, using the specified password.
    If *bssid* is given then the connection will be restricted to the
    access-point with that MAC address (the *ssid* must also be specified
    in this case).

.. method:: wlan.disconnect()

    Disconnect from the currently connected wireless network.

.. method:: wlan.scan()

    Scan for the available wireless networks.

    Scanning is only possible on STA interface. Returns list of tuples with
    the information about WiFi access points:

        (ssid, bssid, channel, RSSI, authmode, hidden)

    *bssid* is hardware address of an access point, in binary form, returned as
    bytes object. You can use `binascii.hexlify()` to convert it to ASCII form.

    There are five values for authmode:

        * 0 -- open
        * 1 -- WEP
        * 2 -- WPA-PSK
        * 3 -- WPA2-PSK
        * 4 -- WPA/WPA2-PSK

    and two for hidden:

        * 0 -- visible
        * 1 -- hidden

.. method:: wlan.status()

    Return the current status of the wireless connection.

    The possible statuses are defined as constants:

        * ``STAT_IDLE`` -- no connection and no activity,
        * ``STAT_CONNECTING`` -- connecting in progress,
        * ``STAT_WRONG_PASSWORD`` -- failed due to incorrect password,
        * ``STAT_NO_AP_FOUND`` -- failed because no access point replied,
        * ``STAT_CONNECT_FAIL`` -- failed due to other problems,
        * ``STAT_GOT_IP`` -- connection successful.

.. method:: wlan.isconnected()

    In case of STA mode, returns ``True`` if connected to a WiFi access
    point and has a valid IP address.  In AP mode returns ``True`` when a
    station is connected. Returns ``False`` otherwise.

.. method:: wlan.ifconfig([(ip, subnet, gateway, dns)])

   Get/set IP-level network interface parameters: IP address, subnet mask,
   gateway and DNS server. When called with no arguments, this method returns
   a 4-tuple with the above information. To set the above values, pass a
   4-tuple with the required information.  For example::

    nic.ifconfig(('192.168.0.4', '255.255.255.0', '192.168.0.1', '8.8.8.8'))

.. method:: wlan.config('param')
.. method:: wlan.config(param=value, ...)

   Get or set general network interface parameters. These methods allow to work
   with additional parameters beyond standard IP configuration (as dealt with by
   `wlan.ifconfig()`). These include network-specific and hardware-specific
   parameters. For setting parameters, keyword argument syntax should be used,
   multiple parameters can be set at once. For querying, parameters name should
   be quoted as a string, and only one parameter can be queries at time::

    # Set WiFi access point name (formally known as ESSID) and WiFi channel
    ap.config(essid='My AP', channel=11)
    # Query params one by one
    print(ap.config('essid'))
    print(ap.config('channel'))

   Following are commonly supported parameters (availability of a specific parameter
   depends on network technology type, driver, and ``MicroPython port``).

   =============  ===========
   Parameter      Description
   =============  ===========
   mac            MAC address (bytes)
   essid          WiFi access point name (string)
   channel        WiFi channel (integer)
   hidden         Whether ESSID is hidden (boolean)
   authmode       Authentication mode supported (enumeration, see module constants)
   password       Access password (string)
   dhcp_hostname  The DHCP hostname to use
   =============  ===========
