# Copyright (c) 2016-present, Gregory Szorc

# All rights reserved.

#

# This software may be modified and distributed under the terms

# of the BSD license. See the LICENSE file for details.

import distutils.ccompiler

import os

from distutils.extension import Extension

zstd_sources = ['zstd/%s' % p for p in (

    'common/debug.c',

    'common/entropy_common.c',

    'common/error_private.c',

    'common/fse_decompress.c',

    'common/pool.c',

    'common/threading.c',

    'common/xxhash.c',

    'common/zstd_common.c',

    'compress/fse_compress.c',

    'compress/hist.c',

    'compress/huf_compress.c',

    'compress/zstd_compress.c',

    'compress/zstd_double_fast.c',

    'compress/zstd_fast.c',

    'compress/zstd_lazy.c',

    'compress/zstd_ldm.c',

    'compress/zstd_opt.c',

    'compress/zstdmt_compress.c',

    'decompress/huf_decompress.c',

    'decompress/zstd_decompress.c',

    'dictBuilder/cover.c',

    'dictBuilder/divsufsort.c',

    'dictBuilder/fastcover.c',

    'dictBuilder/zdict.c',

)]

zstd_sources_legacy = ['zstd/%s' % p for p in (

    'deprecated/zbuff_common.c',

    'deprecated/zbuff_compress.c',

    'deprecated/zbuff_decompress.c',

    'legacy/zstd_v01.c',

    'legacy/zstd_v02.c',

    'legacy/zstd_v03.c',

    'legacy/zstd_v04.c',

    'legacy/zstd_v05.c',

    'legacy/zstd_v06.c',

    'legacy/zstd_v07.c'

)]

zstd_includes = [

    'zstd',

    'zstd/common',

    'zstd/compress',

    'zstd/decompress',

    'zstd/dictBuilder',

]

zstd_includes_legacy = [

    'zstd/deprecated',

    'zstd/legacy',

]

ext_includes = [

    'c-ext',

    'zstd/common',

]

ext_sources = [

    'zstd/common/pool.c',

    'zstd/common/threading.c',

    'zstd.c',

    'c-ext/bufferutil.c',

    'c-ext/compressiondict.c',

    'c-ext/compressobj.c',

    'c-ext/compressor.c',

    'c-ext/compressoriterator.c',

    'c-ext/compressionchunker.c',

    'c-ext/compressionparams.c',

    'c-ext/compressionreader.c',

    'c-ext/compressionwriter.c',

    'c-ext/constants.c',

    'c-ext/decompressobj.c',

    'c-ext/decompressor.c',

    'c-ext/decompressoriterator.c',

    'c-ext/decompressionreader.c',

    'c-ext/decompressionwriter.c',

    'c-ext/frameparams.c',

]

zstd_depends = [

    'c-ext/python-zstandard.h',

]

def get_c_extension(support_legacy=False, system_zstd=False, name='zstd',

                    warnings_as_errors=False, root=None):

    """Obtain a distutils.extension.Extension for the C extension.

    ``support_legacy`` controls whether to compile in legacy zstd format support.

    ``system_zstd`` controls whether to compile against the system zstd library.

    For this to work, the system zstd library and headers must match what

    python-zstandard is coded against exactly.

    ``name`` is the module name of the C extension to produce.

    ``warnings_as_errors`` controls whether compiler warnings are turned into

    compiler errors.

    ``root`` defines a root path that source should be computed as relative

    to. This should be the directory with the main ``setup.py`` that is

    being invoked. If not defined, paths will be relative to this file.

    """

    actual_root = os.path.abspath(os.path.dirname(__file__))

    root = root or actual_root

    sources = set([os.path.join(actual_root, p) for p in ext_sources])

    if not system_zstd:

        sources.update([os.path.join(actual_root, p) for p in zstd_sources])

        if support_legacy:

            sources.update([os.path.join(actual_root, p)

                            for p in zstd_sources_legacy])

    sources = list(sources)

    include_dirs = set([os.path.join(actual_root, d) for d in ext_includes])

    if not system_zstd:

        include_dirs.update([os.path.join(actual_root, d)

                             for d in zstd_includes])

        if support_legacy:

            include_dirs.update([os.path.join(actual_root, d)

                                 for d in zstd_includes_legacy])

    include_dirs = list(include_dirs)

    depends = [os.path.join(actual_root, p) for p in zstd_depends]

    compiler = distutils.ccompiler.new_compiler()

    # Needed for MSVC.

    if hasattr(compiler, 'initialize'):

        compiler.initialize()

    if compiler.compiler_type == 'unix':

        compiler_type = 'unix'

    elif compiler.compiler_type == 'msvc':

        compiler_type = 'msvc'

    elif compiler.compiler_type == 'mingw32':

        compiler_type = 'mingw32'

    else:

        raise Exception('unhandled compiler type: %s' %

                        compiler.compiler_type)

    extra_args = ['-DZSTD_MULTITHREAD']

    if not system_zstd:

        extra_args.append('-DZSTDLIB_VISIBILITY=')

        extra_args.append('-DZDICTLIB_VISIBILITY=')

        extra_args.append('-DZSTDERRORLIB_VISIBILITY=')

        if compiler_type == 'unix':

            extra_args.append('-fvisibility=hidden')

    if not system_zstd and support_legacy:

        extra_args.append('-DZSTD_LEGACY_SUPPORT=1')

    if warnings_as_errors:

        if compiler_type in ('unix', 'mingw32'):

            extra_args.append('-Werror')

        elif compiler_type == 'msvc':

            extra_args.append('/WX')

        else:

            assert False

    libraries = ['zstd'] if system_zstd else []

    # Python 3.7 doesn't like absolute paths. So normalize to relative.

    sources = [os.path.relpath(p, root) for p in sources]

    include_dirs = [os.path.relpath(p, root) for p in include_dirs]

    depends = [os.path.relpath(p, root) for p in depends]

    # TODO compile with optimizations.

    return Extension(name, sources,

                     include_dirs=include_dirs,

                     depends=depends,

                     extra_compile_args=extra_args,

                     libraries=libraries)