# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.


"""
Serial Port Protocol
"""


# dependent on pyserial ( http://pyserial.sf.net/ )
# only tested w/ 1.18 (5 Dec 2002)
from serial import EIGHTBITS, PARITY_NONE, STOPBITS_ONE

from twisted.internet import abstract, fdesc
from twisted.internet.serialport import BaseSerialPort


class SerialPort(BaseSerialPort, abstract.FileDescriptor):
    """
    A select()able serial device, acting as a transport.
    """

    connected = 1

    def __init__(
        self,
        protocol,
        deviceNameOrPortNumber,
        reactor,
        baudrate=9600,
        bytesize=EIGHTBITS,
        parity=PARITY_NONE,
        stopbits=STOPBITS_ONE,
        timeout=0,
        xonxoff=0,
        rtscts=0,
    ):
        abstract.FileDescriptor.__init__(self, reactor)
        self._serial = self._serialFactory(
            deviceNameOrPortNumber,
            baudrate=baudrate,
            bytesize=bytesize,
            parity=parity,
            stopbits=stopbits,
            timeout=timeout,
            xonxoff=xonxoff,
            rtscts=rtscts,
        )
        self.reactor = reactor
        self.flushInput()
        self.flushOutput()
        self.protocol = protocol
        self.protocol.makeConnection(self)
        self.startReading()

    def fileno(self):
        return self._serial.fd

    def writeSomeData(self, data):
        """
        Write some data to the serial device.
        """
        return fdesc.writeToFD(self.fileno(), data)

    def doRead(self):
        """
        Some data's readable from serial device.
        """
        return fdesc.readFromFD(self.fileno(), self.protocol.dataReceived)

    def connectionLost(self, reason):
        """
        Called when the serial port disconnects.

        Will call C{connectionLost} on the protocol that is handling the
        serial data.
        """
        abstract.FileDescriptor.connectionLost(self, reason)
        self._serial.close()
        self.protocol.connectionLost(reason)