#!/usr/bin/env python

"""Unique place where the version number is defined.

provides:
* version = "1.2.3" or "1.2.3-beta4"
* version_info = named tuple (1,2,3,"beta",4)
* hexversion: 0x010203B4
* strictversion = "1.2.3b4
* debianversion = "1.2.3~beta4"
* calc_hexversion: the function to transform a version_tuple into an integer

This is called hexversion since it only really looks meaningful when viewed as the
result of passing it to the built-in hex() function.
The version_info value may be used for a more human-friendly encoding of the same information.

The hexversion is a 32-bit number with the following layout:
Bits (big endian order)     Meaning
1-8     PY_MAJOR_VERSION (the 2 in 2.1.0a3)
9-16     PY_MINOR_VERSION (the 1 in 2.1.0a3)
17-24     PY_MICRO_VERSION (the 0 in 2.1.0a3)
25-28     PY_RELEASE_LEVEL (0xA for alpha, 0xB for beta, 0xC for release candidate and 0xF for final)
29-32     PY_RELEASE_SERIAL (the 3 in 2.1.0a3, zero for final releases)

Thus 2.1.0a3 is hexversion 0x020100a3.

"""

from collections import namedtuple

__authors__ = ["Jérôme Kieffer"]
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"
__date__ = "28/02/2018"
__status__ = "production"
__docformat__ = "restructuredtext"
__all__ = [
    "date",
    "version_info",
    "strictversion",
    "hexversion",
    "debianversion",
    "calc_hexversion",
]

RELEASE_LEVEL_VALUE = {
    "dev": 0,
    "alpha": 10,
    "beta": 11,
    "gamma": 12,
    "rc": 13,
    "final": 15,
}

MAJOR = 2
MINOR = 1
MICRO = 2
RELEV = "final"  # <16
SERIAL = 0

date = __date__


_version_info = namedtuple(
    "version_info", ["major", "minor", "micro", "releaselevel", "serial"]
)

version_info = _version_info(MAJOR, MINOR, MICRO, RELEV, SERIAL)

strictversion = version = debianversion = "%d.%d.%d" % version_info[:3]
if version_info.releaselevel != "final":
    version += "-%s%s" % version_info[-2:]
    debianversion += (
        "~adev%i" % version_info[-1] if RELEV == "dev" else "~%s%i" % version_info[-2:]
    )
    prerel = "a" if RELEASE_LEVEL_VALUE.get(version_info[3], 0) < 10 else "b"
    if prerel not in "ab":
        prerel = "a"
    strictversion += prerel + str(version_info[-1])


def calc_hexversion(major=0, minor=0, micro=0, releaselevel="dev", serial=0):
    """Calculate the hexadecimal version number from the tuple version_info:

    :param major: integer
    :param minor: integer
    :param micro: integer
    :param relev: integer or string
    :param serial: integer
    :return: integer always increasing with revision numbers
    """
    try:
        releaselevel = int(releaselevel)
    except ValueError:
        releaselevel = RELEASE_LEVEL_VALUE.get(releaselevel, 0)

    hex_version = int(serial)
    hex_version |= releaselevel * 1 << 4
    hex_version |= int(micro) * 1 << 8
    hex_version |= int(minor) * 1 << 16
    hex_version |= int(major) * 1 << 24
    return hex_version


hexversion = calc_hexversion(*version_info)


if __name__ == "__main__":
    print(version)
