#!/usr/bin/env python
# -*- coding: utf-8 -*-

# MIT License
#
# Copyright 2018-2024 New York University Abu Dhabi
#
# 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


def open_files(finpath, foutpath):
    if finpath is None:
        fin = sys.stdin
    else:
        try:
            fin = open(finpath, 'r', encoding='utf-8')
        except OSError:
            sys.stderr.write('Error: Couldn\'t open input file {}.'
                             '\n'.format(repr(finpath)))
            sys.exit(1)

    if foutpath is None:
        fout = sys.stdout
    else:
        try:
            fout = open(foutpath, 'w', encoding='utf-8')
        except OSError:
            sys.stderr.write('Error: Couldn\'t open output file {}.'
                             '\n'.format(repr(foutpath)))
            if finpath is not None:
                fin.close()
            sys.exit(1)

    return fin, fout
