# MIT License
#
# Copyright (c) 2022 Eugenio Parodi <ceccopierangiolieugenio AT googlemail DOT com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import sys, os, re
from select import select

try: import fcntl, termios, tty
except Exception as e:
    print(f'ERROR: {e}')
    exit(1)


class ReadInput():
    __slots__ = ('_readPipe','_attr')

    def __init__(self):
        self._readPipe = os.pipe()
        self._attr = termios.tcgetattr(sys.stdin)
        tty.setcbreak(sys.stdin)

    def close(self):
        termios.tcsetattr(sys.stdin, termios.TCSANOW, self._attr)
        os.write(self._readPipe[1], b'quit')

    def cont(self):
        tty.setcbreak(sys.stdin)

    def read(self):
        rm = re.compile('(\033?[^\033]+)')
        while self._readPipe[0] not in (list := select( [sys.stdin, self._readPipe[0]], [], [] )[0]):
            # Read all the full input
            _fl = fcntl.fcntl(sys.stdin, fcntl.F_GETFL)
            fcntl.fcntl(sys.stdin, fcntl.F_SETFL, _fl | os.O_NONBLOCK) # Set the input as NONBLOCK to read the full sequence
            stdinRead = sys.stdin.read()
            fcntl.fcntl(sys.stdin, fcntl.F_SETFL, _fl)

            # Split all the ansi sequences
            # or yield any separate input char
            if stdinRead == '\033':
                yield '\033'
                continue
            for sr in rm.findall(stdinRead):
                if '\033' == sr[0]:
                    yield sr
                else:
                    for ch in sr:
                        yield ch