# Copyright (c) 2020 ARM Limited
# All rights reserved
#
# The license below extends only to copyright in the software and shall
# not be construed as granting a license to any other intellectual
# property including but not limited to intellectual property relating
# to a hardware implementation of the functionality of the software
# licensed hereunder.  You may use the software subject to the license
# terms below provided that you ensure that this notice is replicated
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# modified or unmodified, in source code or in binary form.
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# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer;
# redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
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# neither the name of the copyright holders nor the names of its
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# this software without specific prior written permission.
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"""
Utilities to parse and modify copyright headers in gem5 source.
"""

import re

org_alias_map = {
    'arm': b'ARM Limited',
    'uc': b'The Regents of the University of California',
}

_update_copyright_year_regexp = re.compile(b'(.*?)([0-9]+)$')

def _update_copyright_years(m, cur_year, org_bytes):
    '''
    Does e.g.: b'2016, 2018-2019' -> b'2016, 2018-2020'.

    :param m: match containing only the years part of the string
    :type m: re.Match
    :param cur_year: the current year to update the copyright to
    :type cur_year: int
    :return: the new years part of the string
    :rtype: bytes
    '''
    global _update_copyright_year_regexp
    cur_year_bytes = str(cur_year).encode()
    m = _update_copyright_year_regexp.match(m.group(1))
    years_prefix = m.group(1)
    old_year_bytes = m.group(2)
    old_year = int(old_year_bytes.decode())
    if old_year == cur_year:
        new_years_string = old_year_bytes
    elif old_year == cur_year - 1:
        if len(years_prefix) > 0 and years_prefix[-1:] == b'-':
            new_years_string = cur_year_bytes
        else:
            new_years_string = old_year_bytes + b'-' + cur_year_bytes
    else:
        new_years_string = old_year_bytes + b', ' + cur_year_bytes
    new_years_string = years_prefix + new_years_string
    return b' Copyright (c) %b %b\n' % (new_years_string, org_bytes)

def update_copyright(data, cur_year, org_bytes):
    update_copyright_regexp = re.compile(
        b' Copyright \\(c\\) ([0-9,\- ]+) ' + org_bytes + b'\n',
        re.IGNORECASE
    )
    return update_copyright_regexp.sub(
        lambda m: _update_copyright_years(m, cur_year, org_bytes),
        data,
        count=1,
    )