From 1316df452bff97106dc9313fe9458c93d7f954ab Mon Sep 17 00:00:00 2001
From: Alexander Bessman <alexander.bessman@gmail.com>
Date: Wed, 19 Feb 2025 15:14:22 +0100
Subject: [PATCH] Add WLANHandler

---
 pslab/connection/__init__.py |  11 ++++
 pslab/connection/wlan.py     | 113 +++++++++++++++++++++++++++++++++++
 tox.ini                      |   2 +-
 3 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 pslab/connection/wlan.py

diff --git a/pslab/connection/__init__.py b/pslab/connection/__init__.py
index 0b5abcb..fe7b50a 100644
--- a/pslab/connection/__init__.py
+++ b/pslab/connection/__init__.py
@@ -4,6 +4,7 @@
 
 from .connection import ConnectionHandler
 from ._serial import SerialHandler
+from .wlan import WLANHandler
 
 
 def detect() -> list[ConnectionHandler]:
@@ -36,6 +37,16 @@ def detect() -> list[ConnectionHandler]:
         finally:
             device.disconnect()
 
+    try:
+        device = WLANHandler()
+        device.connect()
+    except Exception:
+        pass  # nosec
+    else:
+        pslab_devices.append(device)
+    finally:
+        device.disconnect()
+
     return pslab_devices
 
 
diff --git a/pslab/connection/wlan.py b/pslab/connection/wlan.py
new file mode 100644
index 0000000..66be153
--- /dev/null
+++ b/pslab/connection/wlan.py
@@ -0,0 +1,113 @@
+"""Wireless interface for communicating with PSLab devices equiped with ESP8266."""
+
+import socket
+
+from pslab.connection.connection import ConnectionHandler
+
+
+class WLANHandler(ConnectionHandler):
+    """Interface for controlling a PSLab over WLAN.
+
+    Paramaters
+    ----------
+    host : str, default 192.168.4.1
+        Network address of the PSLab.
+    port : int, default 80
+    timeout : float, default 1 s
+    """
+
+    def __init__(
+        self,
+        host: str = "192.168.4.1",
+        port: int = 80,
+        timeout: float = 1.0,
+    ) -> None:
+        self._host = host
+        self._port = port
+        self._timeout = timeout
+        self._sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self._sock.settimeout(timeout)
+
+    @property
+    def host(self) -> int:
+        """Network address of the PSLab."""
+        return self._host
+
+    @property
+    def port(self) -> int:
+        """TCP port number."""
+        return self._port
+
+    @property
+    def timeout(self) -> float:
+        """Timeout in seconds."""
+        return self._timeout
+
+    @timeout.setter
+    def timeout(self, value: float) -> None:
+        self._sock.settimeout(value)
+
+    def connect(self) -> None:
+        """Connect to PSLab."""
+        if self._sock.fileno() == -1:
+            # Socket has been closed.
+            self._sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            self._sock.settimeout(self.timeout)
+
+        self._sock.connect((self.host, self.port))
+
+        try:
+            self.get_version()
+        except Exception:
+            self._sock.close()
+            raise
+
+    def disconnect(self) -> None:
+        """Disconnect from PSLab."""
+        self._sock.close()
+
+    def read(self, numbytes: int) -> bytes:
+        """Read data over WLAN.
+
+        Parameters
+        ----------
+        numbytes : int
+            Number of bytes to read.
+
+        Returns
+        -------
+        data : bytes
+        """
+        received = b""
+        buf_size = 4096
+        remaining = numbytes
+
+        while remaining > 0:
+            chunk = self._sock.recv(min(remaining, buf_size))
+            received += chunk
+            remaining -= len(chunk)
+
+        return received
+
+    def write(self, data: bytes) -> int:
+        """Write data over WLAN.
+
+        Parameters
+        ----------
+        data : bytes
+
+        Returns
+        -------
+        numbytes : int
+            Number of bytes written.
+        """
+        return self._sock.sendall(data)
+
+    def __repr__(self) -> str:  # noqa
+        return (
+            f"{self.__class__.__name__}"
+            "["
+            f"{self.host}:{self.port}, "
+            f"timeout {self.timeout} s"
+            "]"
+        )
diff --git a/tox.ini b/tox.ini
index a7ee8ac..00be71d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,7 @@ commands = coverage run --source pslab -m pytest
 [testenv:lint]
 deps = -rlint-requirements.txt
 setenv =
-    INCLUDE_PSL_FILES = pslab/bus/ pslab/instrument/ pslab/serial_handler.py pslab/cli.py pslab/external/motor.py pslab/external/gas_sensor.py pslab/external/hcsr04.py
+    INCLUDE_PSL_FILES = pslab/bus/ pslab/connection pslab/instrument/ pslab/serial_handler.py pslab/cli.py pslab/external/motor.py pslab/external/gas_sensor.py pslab/external/hcsr04.py
 commands =
     black --check {env:INCLUDE_PSL_FILES}
     flake8 --show-source {env:INCLUDE_PSL_FILES}