# Low level unix utility functions
#
# Copyright (C) 2016-2020  Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import os, pty, fcntl, termios, signal, logging
import traceback


######################################################################
# Low-level Unix commands
######################################################################


# Return the SIGINT interrupt handler back to the OS default
def fix_sigint():
    signal.signal(signal.SIGINT, signal.SIG_DFL)


fix_sigint()


# Set a file-descriptor as non-blocking
def set_nonblock(fd):
    fcntl.fcntl(fd, fcntl.F_SETFL, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)


# Clear HUPCL flag
def clear_hupcl(fd):
    attrs = termios.tcgetattr(fd)
    attrs[2] = attrs[2] & ~termios.HUPCL
    try:
        termios.tcsetattr(fd, termios.TCSADRAIN, attrs)
    except termios.error:
        pass


# Support for creating a pseudo-tty for emulating a serial port
def create_pty(ptyname):
    mfd, sfd = pty.openpty()
    try:
        os.unlink(ptyname)
    except os.error:
        pass
    filename = os.ttyname(sfd)
    os.chmod(filename, 0o660)
    os.symlink(filename, ptyname)
    set_nonblock(mfd)
    old = termios.tcgetattr(mfd)
    old[3] = old[3] & ~termios.ECHO
    termios.tcsetattr(mfd, termios.TCSADRAIN, old)
    return mfd


######################################################################
# General system and software information
######################################################################


def get_cpu_info():
    try:
        f = open("/proc/cpuinfo", "r")
        data = f.read()
        f.close()
    except (IOError, OSError) as e:
        logging.debug("Exception on read /proc/cpuinfo: %s", traceback.format_exc())
        return "?"
    lines = [l.split(":", 1) for l in data.split("\n")]
    lines = [(l[0].strip(), l[1].strip()) for l in lines if len(l) == 2]
    core_count = [k for k, v in lines].count("processor")
    model_name = dict(lines).get("model name", "?")
    return "%d core %s" % (core_count, model_name)