"""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 dlib:
    python setup.py build
To build and install:
    python setup.py install
To upload the source distribution to PyPi
    python setup.py sdist 
    twine upload dist/dlib-*.tar.gz
To exclude certain options in the cmake config use --no:
    for example:
    --no USE_AVX_INSTRUCTIONS: will set -DUSE_AVX_INSTRUCTIONS=no
Additional options:
    --compiler-flags: pass flags onto the compiler, e.g. --compiler-flags "-Os -Wall" passes -Os -Wall onto GCC.
    -G: Set the CMake generator.  E.g. -G "Visual Studio 14 2015"
    --clean: delete any previous build folders and rebuild.  You should do this if you change any build options
             by setting --compiler-flags or --no since the last time you ran a build.  This will
             ensure the changes take effect.
    --set: set arbitrary cmake options e.g. --set CUDA_HOST_COMPILER=/usr/bin/gcc-6.4.0
           passes -DCUDA_HOST_COMPILER=/usr/bin/gcc-6.4.0 to CMake.
"""
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 find_packages, setup, Extension
from setuptools.command.build_ext import build_ext
from distutils.version import LooseVersion


def get_extra_cmake_options():
    """read --clean, --no, --set, --compiler-flags, and -G 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 arg in argv:
        if opt_key == 'compiler-flags':
            _cmake_extra_options.append('-DCMAKE_CXX_FLAGS={arg}'.format(arg=arg.strip()))
        elif opt_key == 'G':
            _cmake_extra_options += ['-G', arg.strip()]
        elif opt_key == 'no':
            _cmake_extra_options.append('-D{arg}=no'.format(arg=arg.strip()))
        elif opt_key == 'set':
            _cmake_extra_options.append('-D{arg}'.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 == '--yes':
            print("The --yes options to dlib's setup.py don't do anything since all these options ")
            print("are on by default.  So --yes has been removed.  Do not give it to setup.py.")
            sys.exit(1)
        if arg in ['--no', '--set', '--compiler-flags']:
            opt_key = arg[2:].lower()
            sys.argv.remove(arg)
            continue
        if arg in ['-G']:
            opt_key = arg[1:]
            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:
            sys.stderr.write("\nERROR: CMake must be installed to build dlib\n\n") 
            sys.exit(1)
        return re.search(r'version\s*([\d.]+)', out.decode()).group(1)

    def run(self):
        cmake_version = self.get_cmake_version()
        if platform.system() == "Windows":
            if LooseVersion(cmake_version) < '3.1.0':
                sys.stderr.write("\nERROR: CMake >= 3.1.0 is required on Windows\n\n")
                sys.exit(1)

        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']
            # Do a parallel build
            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("Building extension for Python {}".format(sys.version.split('\n',1)[0]))
        print("Invoking CMake setup: '{}'".format(' '.join(cmake_setup)))
        sys.stdout.flush()
        subprocess.check_call(cmake_setup, cwd=build_folder)
        print("Invoking CMake build: '{}'".format(' '.join(cmake_build)))
        sys.stdout.flush()
        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 = '--ignore docs --ignore dlib'

    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='See http://dlib.net for documentation.',
    author='Davis King',
    author_email='davis@dlib.net',
    url='https://github.com/davisking/dlib',
    license='Boost Software License',
    ext_modules=[CMakeExtension('_dlib_pybind11','tools/python')],
    cmdclass=dict(build_ext=CMakeBuild, test=PyTest),
    zip_safe=False,
    # We need an older more-itertools version because v6 broke pytest (for everyone, not just dlib)
    tests_require=['pytest==3.8', 'more-itertools<6.0.0'],
    #install_requires=['cmake'], # removed because the pip cmake package is busted, maybe someday it will be usable.
    packages=find_packages(exclude=['python_examples']),
    package_dir={'': 'tools/python'},
    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',
        'Topic :: Scientific/Engineering',
        'Topic :: Scientific/Engineering :: Artificial Intelligence',
        'Topic :: Scientific/Engineering :: Image Recognition',
        'Topic :: Software Development',
    ],
)
