"""setup for the dlib project
 Copyright (C) 2015  Ehsan Azar (dashesy@linux.com)
 License: Boost Software License   See LICENSE.txt for the full license.

This file basically just uses CMake to compile the dlib python bindings project
located in the tools/python folder and then puts the outputs into standard
python packages.

To build the dlib:
    python setup.py build
To build and install:
    python setup.py install
To package the wheel (after pip installing twine and wheel):
    python setup.py bdist_wheel
To upload the binary wheel to PyPi
    twine upload dist/*.whl
To upload the source distribution to PyPi
    python setup.py sdist upload
To exclude/include certain options in the cmake config use --yes and --no:
    for example:
    --yes USE_AVX_INSTRUCTIONS: will set -DUSE_AVX_INSTRUCTIONS=yes
    --no USE_AVX_INSTRUCTIONS: will set -DUSE_AVX_INSTRUCTIONS=no
Additional options:
    --compiler-flags: pass flags onto the compiler, e.g. --compiler-flag "-Os -Wall" passes -Os -Wall onto GCC.
    --clean: delete any previous build folders and rebuild.  You should do this if you change any build options
             by setting --compiler-flags or --yes or --no since last time you ran a build to make sure the changes
             take effect.
"""
import os
import re
import sys
import shutil
import platform
import subprocess
import multiprocessing
from distutils import log
from math import ceil,floor

from setuptools import setup, Extension
from setuptools.command.build_ext import build_ext
from distutils.version import LooseVersion


def get_extra_cmake_options():
    """read --clean, --yes, --no, and --compiler-flag options from the command line and add them as cmake switches.
    """
    _cmake_extra_options = []
    _clean_build_folder = False

    opt_key = None

    argv = [arg for arg in sys.argv]  # take a copy
    # parse command line options and consume those we care about
    for opt_idx, arg in enumerate(argv):
        if opt_key == 'compiler-flags':
            _cmake_extra_options.append('-DCMAKE_CXX_FLAGS={arg}'.format(arg=arg.strip()))
        elif opt_key == 'yes':
            _cmake_extra_options.append('-D{arg}=yes'.format(arg=arg.strip()))
        elif opt_key == 'no':
            _cmake_extra_options.append('-D{arg}=no'.format(arg=arg.strip()))

        if opt_key:
            sys.argv.remove(arg)
            opt_key = None
            continue

        if arg == '--clean':
            _clean_build_folder = True
            sys.argv.remove(arg)
            continue

        if arg in ['--yes', '--no', '--compiler-flags']:
            opt_key = arg[2:].lower()
            sys.argv.remove(arg)
            continue

    return _cmake_extra_options, _clean_build_folder

cmake_extra_options,clean_build_folder = get_extra_cmake_options()


class CMakeExtension(Extension):
    def __init__(self, name, sourcedir=''):
        Extension.__init__(self, name, sources=[])
        self.sourcedir = os.path.abspath(sourcedir)

def rmtree(name):
    """remove a directory and its subdirectories.
    """
    def remove_read_only(func, path, exc):
        excvalue = exc[1]
        if func in (os.rmdir, os.remove) and excvalue.errno == errno.EACCES:
            os.chmod(path, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
            func(path)
        else:
            raise

    if os.path.exists(name):
        log.info('Removing old directory {}'.format(name))
        shutil.rmtree(name, ignore_errors=False, onerror=remove_read_only)


class CMakeBuild(build_ext):

    def get_cmake_version(self):
        try:
            out = subprocess.check_output(['cmake', '--version'])
        except OSError:
            raise RuntimeError("CMake must be installed to build the following extensions: " +
                               ", ".join(e.name for e in self.extensions))
        return re.search(r'version\s*([\d.]+)', out.decode()).group(1)

    def run(self):
        if platform.system() == "Windows":
            if LooseVersion(self.get_cmake_version()) < '3.1.0':
                raise RuntimeError("CMake >= 3.1.0 is required on Windows")

        for ext in self.extensions:
            self.build_extension(ext)

    def build_extension(self, ext):
        extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))

        cmake_args = ['-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=' + extdir,
                      '-DPYTHON_EXECUTABLE=' + sys.executable]

        cmake_args += cmake_extra_options 

        cfg = 'Debug' if self.debug else 'Release'
        build_args = ['--config', cfg]

        if platform.system() == "Windows":
            cmake_args += ['-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}'.format(cfg.upper(), extdir)]
            if sys.maxsize > 2**32:
                cmake_args += ['-A', 'x64']
            build_args += ['--', '/m']
        else:
            cmake_args += ['-DCMAKE_BUILD_TYPE=' + cfg]
            # Do a parallel build
            build_args += ['--', '-j'+str(num_available_cpu_cores(2))]

        build_folder = os.path.abspath(self.build_temp)

        if clean_build_folder:
            rmtree(build_folder)
        if not os.path.exists(build_folder):
            os.makedirs(build_folder)

        cmake_setup = ['cmake', ext.sourcedir] + cmake_args
        cmake_build = ['cmake', '--build', '.'] + build_args

        print("Invoking CMake setup: '{}'".format(' '.join(cmake_setup)))
        subprocess.check_call(cmake_setup, cwd=build_folder)
        print("Invoking CMake build: '{}'".format(' '.join(cmake_build)))
        subprocess.check_call(cmake_build, cwd=build_folder)

def num_available_cpu_cores(ram_per_build_process_in_gb):
    if 'TRAVIS' in os.environ and os.environ['TRAVIS']=='true':
        # When building on travis-ci, just use 2 cores since travis-ci limits
        # you to that regardless of what the hardware might suggest.
        return 2 
    try:
        mem_bytes = os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES')  
        mem_gib = mem_bytes/(1024.**3)
        num_cores = multiprocessing.cpu_count() 
        # make sure we have enough ram for each build process.
        mem_cores = int(floor(mem_gib/float(ram_per_build_process_in_gb)+0.5));
        # We are limited either by RAM or CPU cores.  So pick the limiting amount
        # and return that.
        return max(min(num_cores, mem_cores), 1)
    except ValueError:
        return 2 # just assume 2 if we can't get the os to tell us the right answer.


from setuptools.command.test import test as TestCommand
class PyTest(TestCommand):
    user_options = [('pytest-args=', 'a', "Arguments to pass to pytest")]

    def initialize_options(self):
        TestCommand.initialize_options(self)
        self.pytest_args = ''

    def run_tests(self):
        import shlex
        #import here, cause outside the eggs aren't loaded
        import pytest
        errno = pytest.main(shlex.split(self.pytest_args))
        sys.exit(errno)

def read_version_from_cmakelists(cmake_file):
    """Read version information
    """
    major = re.findall("set\(CPACK_PACKAGE_VERSION_MAJOR.*\"(.*)\"", open(cmake_file).read())[0]
    minor = re.findall("set\(CPACK_PACKAGE_VERSION_MINOR.*\"(.*)\"", open(cmake_file).read())[0]
    patch = re.findall("set\(CPACK_PACKAGE_VERSION_PATCH.*\"(.*)\"", open(cmake_file).read())[0]
    return major + '.' + minor + '.' + patch

def read_entire_file(fname):
    """Read text out of a file relative to setup.py.
    """
    return open(os.path.join(fname)).read()

setup(
    name='dlib',
    version=read_version_from_cmakelists('dlib/CMakeLists.txt'),
    description='A toolkit for making real world machine learning and data analysis applications',
    long_description=read_entire_file('README.md'),
    author='Davis King',
    author_email='davis@dlib.net',
    url='https://github.com/davisking/dlib',
    license='Boost Software License',
    ext_modules=[CMakeExtension('dlib','tools/python')],
    cmdclass=dict(build_ext=CMakeBuild, test=PyTest),
    zip_safe=False,
    tests_require=['pytest'],
    packages=['dlib'],
    keywords=['dlib', 'Computer Vision', 'Machine Learning'],
    classifiers=[
        'Development Status :: 5 - Production/Stable',
        'Intended Audience :: Science/Research',
        'Intended Audience :: Developers',
        'Operating System :: MacOS :: MacOS X',
        'Operating System :: POSIX',
        'Operating System :: POSIX :: Linux',
        'Operating System :: Microsoft',
        'Operating System :: Microsoft :: Windows',
        'Programming Language :: C++',
        'Programming Language :: Python',
        'Programming Language :: Python :: 2',
        'Programming Language :: Python :: 2.6',
        'Programming Language :: Python :: 2.7',
        'Programming Language :: Python :: 3',
        'Programming Language :: Python :: 3.4',
        'Programming Language :: Python :: 3.5',
        'Programming Language :: Python :: 3.6',
        'Topic :: Scientific/Engineering',
        'Topic :: Scientific/Engineering :: Artificial Intelligence',
        'Topic :: Scientific/Engineering :: Image Recognition',
        'Topic :: Software Development',
    ],
)
