#!/usr/bin/env python2

"""
setup.py file for SWIG libfdt
Copyright (C) 2017 Google, Inc.
Written by Simon Glass <sjg@chromium.org>

Version is provided in VERSION

If these variables are not given they are parsed from the Makefiles. This
allows this script to be run stand-alone, e.g.:

    ./pylibfdt/setup.py install [--prefix=...]
"""

from distutils.core import setup, Extension
import os
import re
import sys

# Decodes a Makefile assignment line into key and value (and plus for +=)
RE_KEY_VALUE = re.compile('(?P<key>\w+) *(?P<plus>[+])?= *(?P<value>.*)$')


def ParseMakefile(fname):
    """Parse a Makefile to obtain its variables.

    This collects variable assigments of the form:

        VAR = value
        VAR += more

    It does not pick out := assignments, as these are not needed here. It does
    handle line continuation.

    Returns a dict:
        key: Variable name (e.g. 'VAR')
        value: Variable value (e.g. 'value more')
    """
    makevars = {}
    with open(fname) as fd:
        prev_text = ''  # Continuation text from previous line(s)
        for line in fd.read().splitlines():
          if line and line[-1] == '\\':  # Deal with line continuation
            prev_text += line[:-1]
            continue
          elif prev_text:
            line = prev_text + line
            prev_text = ''  # Continuation is now used up
          m = RE_KEY_VALUE.match(line)
          if m:
            value = m.group('value') or ''
            key = m.group('key')

            # Appending to a variable inserts a space beforehand
            if 'plus' in m.groupdict() and key in makevars:
              makevars[key] += ' ' + value
            else:
              makevars[key] = value
    return makevars

def GetEnvFromMakefiles():
    """Scan the Makefiles to obtain the settings we need.

    This assumes that this script is being run from the top-level directory,
    not the pylibfdt directory.

    Returns:
        Tuple with:
            Version string
            List of extra C preprocessor flags needed
    """
    basedir = os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0])))
    makevars = ParseMakefile(os.path.join(basedir, 'Makefile'))
    version = '%s.%s.%s' % (makevars['VERSION'], makevars['PATCHLEVEL'],
                            makevars['SUBLEVEL'])
    return version


progname = sys.argv[0]
version = os.environ.get('VERSION')

# If we were called directly rather than through our Makefile (which is often
# the case with Python module installation), read the settings from the
# Makefile.
if not version:
    version = GetEnvFromMakefiles()

libfdt_module = Extension(
    '_libfdt',
    sources = ['pylibfdt/libfdt.i'],
    include_dirs = ['libfdt'],
    libraries = ['fdt'],
    library_dirs = ['libfdt'],
)

setup(
    name='libfdt',
    version= version,
    author='Simon Glass <sjg@chromium.org>',
    description='Python binding for libfdt',
    ext_modules=[libfdt_module],
    py_modules=['pylibfdt/libfdt'],
)