# Copyright 2017 Linaro Limited
# Copyright (c) 2018, Arm Limited.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Semi Semantic Versioning

Implements a subset of semantic versioning that is supportable by the image header.
"""

import argparse
from collections import namedtuple
import re

SemiSemVersion = namedtuple('SemiSemVersion', ['major', 'minor', 'revision', 'build'])

def increment_build_num(lastVer):
    newVer = SemiSemVersion(lastVer.major, lastVer.minor, lastVer.revision, lastVer.build + 1)
    return newVer

# -1 if a is older than b; 0 if they're the same version; 1 if a is newer than b
def compare(a, b):
    if (a.major > b.major): return 1
    elif (a.major < b.major): return -1
    else:
        if (a.minor > b.minor): return 1
        elif (a.minor < b.minor): return -1
        else:
            if (a.revision > b.revision): return 1
            elif (a.revision < b.revision): return -1
            else:
                if (a.build > b.build): return 1
                elif (a.build < b.build): return -1
                else: return 0

version_re = re.compile(r"""^([1-9]\d*|0)(\.([1-9]\d*|0)(\.([1-9]\d*|0)(\+([1-9]\d*|0))?)?)?$""")
def decode_version(text):
    """Decode the version string, which should be of the form maj.min.rev+build"""
    m = version_re.match(text)
    if m:
        result = SemiSemVersion(
                int(m.group(1)) if m.group(1) else 0,
                int(m.group(3)) if m.group(3) else 0,
                int(m.group(5)) if m.group(5) else 0,
                int(m.group(7)) if m.group(7) else 0)
        return result
    else:
        msg = "Invalid version number, should be maj.min.rev+build with later parts optional"
        raise argparse.ArgumentTypeError(msg)

if __name__ == '__main__':
    print(decode_version("1.2"))
    print(decode_version("1.0"))
    print(decode_version("0.0.2+75"))
    print(decode_version("0.0.0+00"))