# Copyright (c) 2016-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree. An additional grant
# of patent rights can be found in the PATENTS file in the same directory.

# This file creates an adapter between some internal Facebook-isms and the
# public version of Buck. Over time, this adapter should be unnecesary.


def cpp_library(
    name,
    srcs=None,
    headers=None,
    deps=None,
    output_subdir=None,
    external_deps=None,
):
    # TODO: Handle output_subdir.
    cxx_library(
        name=name,
        srcs=srcs,
        exported_headers=headers,
        deps=_translate_deps(deps, external_deps),
        visibility=[
            'PUBLIC',
        ],
    )


def cpp_binary(
    name,
    output_subdir=None,
    srcs=None,
    deps=None,
    external_deps=None,
):
    # TODO: Handle output_subdir.
    cxx_binary(
        name=name,
        srcs=srcs,
        deps=_translate_deps(deps, external_deps),
    )


def cpp_unittest(
    name,
    srcs=None,
    headers=None,
    deps=None,
    external_deps=None,
):
    cxx_test(
        name=name,
        srcs=srcs,
        headers=None,
        deps=_translate_deps(deps, external_deps),
    )

def cpp_benchmark(
    name,
    srcs=None,
    deps=None,
    external_deps=None,
):
    cxx_binary(
        name=name,
        srcs=srcs,
        deps=_translate_deps(deps, external_deps),
    )


original_python_binary = python_binary
def python_binary(
    name,
    srcs=None,
    gen_srcs=None,
    main_module=None,
    deps=None,
):
    # TODO: Handle gen_srcs.
    original_python_library(
        name=name + '.lib',
        deps=_translate_deps(deps),
    )
    original_python_binary(
        name=name,
        main_module=main_module,
        visibility=[
            'PUBLIC',
        ],
        deps=[':%s.lib' % (name,)]
    )


original_thrift_library = thrift_library
def thrift_library(
    name,
    thrift_srcs=None,
    languages=None,
    deps=None,
    thrift_args=None,
    py_base_module=None,
):
    original_thrift_library(
        name=name,
        srcs=thrift_srcs,
        deps=_translate_deps(deps),
        visibility=['PUBLIC'],
    )

original_python_library = python_library
def python_library(name, deps=None, **kwargs):
    original_python_library(
        name=name,
        deps=_translate_deps(deps),
        visibility=kwargs.pop('visibility', ['PUBLIC']),
        **kwargs
    )


def python_unittest(**kwargs):
    # TODO
    pass

def buck_genrule(**kwargs):
    # TODO
    pass


def _translate_deps(deps, external_deps=None):
    # The translation process may result in duplicates, so use a set
    # to make sure we filter out duplicates.
    translated_deps = set()
    for dep in (deps or ()):
        translated = _translate_dep(dep)
        if translated is not None:
            translated_deps.add(translated)

    for dep in (external_deps or ()):
        translated = _translate_external_dep(dep)
        if translated is not None:
            translated_deps.add(translated)

    if not translated_deps:
        return None
    return list(translated_deps)


def _translate_dep(dep):
    import re
    dep = re.sub('^@/', '//', dep)

    # Translate thrift_library() suffixes
    dep = re.sub('-cpp2$', '#cpp2', dep)
    dep = re.sub('-py$', '#py', dep)
    dep = re.sub('-java$', '#java', dep)

    m = re.match('//(folly|rocksdb|wangle|thrift)[/:]', dep)
    if m:
        libname = m.group(1)
        if libname == 'thrift':
            dep = '//external:thriftcpp2'
        else:
            dep = '//external:%s' % libname
    return dep


def _translate_external_dep(dep):
    if isinstance(dep, tuple):
        # This is a 2-tuple or 3-tuple of
        # project, version constraints, library
        project = dep[0]
        if len(dep) == 3:
            lib = dep[2]
        else:
            lib = project
    else:
        project = dep
        lib = dep

    if project == 'glog':
        return '//external:glog'
    elif project == 'openssl':
        if lib == 'ssl':
            return '//external:openssl_ssl'
        elif lib == 'crypto':
            return '//external:openssl_crypto'
        else:
            raise Exception('unknown openssl lib %r' % lib)
    elif project == 'fuse':
        return '//external:fuse'
    elif project == 'libgit2':
        return '//external:libgit2'
    elif project == 'boost':
        if lib == 'boost':
            # This is headers-only, nothing to add for now.
            return None
        elif lib == 'boost_filesystem':
            return '//external:boost_filesystem'
        else:
            raise Exception('unknown boost lib %r' % lib)
    elif project == 'gtest':
        # buck will add this dependency automatically for
        # cxx_test() rules
        return None
    elif project == 'gmock':
        return '//external:gmock'
    else:
        raise Exception('unhandled external dependency: %r' % project)