# Copyright 2022 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Implementation of py_library rule."""

load(
    ":common/python/attributes.bzl",
    "COMMON_ATTRS",
    "PY_SRCS_ATTRS",
    "SRCS_VERSION_ALL_VALUES",
    "create_srcs_attr",
    "create_srcs_version_attr",
)
load(
    ":common/python/common.bzl",
    "collect_runfiles",
    "create_instrumented_files_info",
    "create_output_group_info",
    "create_py_info",
    "filter_to_py_srcs",
    "union_attrs",
)

_py_builtins = _builtins.internal.py_builtins

LIBRARY_ATTRS = union_attrs(
    COMMON_ATTRS,
    PY_SRCS_ATTRS,
    create_srcs_version_attr(values = SRCS_VERSION_ALL_VALUES),
    create_srcs_attr(mandatory = False),
)

def py_library_impl(ctx, *, semantics):
    """Abstract implementation of py_library rule.

    Args:
        ctx: The rule ctx
        semantics: A `LibrarySemantics` struct; see `create_library_semantics_struct`

    Returns:
        A list of modern providers to propagate.
    """
    direct_sources = filter_to_py_srcs(ctx.files.srcs)
    output_sources = depset(semantics.maybe_precompile(ctx, direct_sources))
    runfiles = collect_runfiles(ctx = ctx, files = output_sources)

    cc_info = semantics.get_cc_info_for_library(ctx)
    py_info, deps_transitive_sources = create_py_info(
        ctx,
        direct_sources = depset(direct_sources),
        imports = semantics.get_imports(ctx),
    )

    # TODO(b/253059598): Remove support for extra actions; https://github.com/bazelbuild/bazel/issues/16455
    listeners_enabled = _py_builtins.are_action_listeners_enabled(ctx)
    if listeners_enabled:
        _py_builtins.add_py_extra_pseudo_action(
            ctx = ctx,
            dependency_transitive_python_sources = deps_transitive_sources,
        )

    return [
        DefaultInfo(files = output_sources, runfiles = runfiles),
        py_info,
        create_instrumented_files_info(ctx),
        _py_builtins.new_py_cc_link_params_provider(cc_info = cc_info),
        create_output_group_info(py_info.transitive_sources),
    ]

def create_py_library_rule(*, attrs = {}, **kwargs):
    """Creates a py_library rule.

    Args:
        attrs: dict of rule attributes.
        **kwargs: Additional kwargs to pass onto the rule() call.
    Returns:
        A rule object
    """
    return rule(
        attrs = LIBRARY_ATTRS | attrs,
        # TODO(b/253818097): fragments=py is only necessary so that
        # RequiredConfigFragmentsTest passes
        fragments = ["py"],
        # Necessary for --compile_one_dependency to give preference to
        # py_library if a .py file is associated with multiple targets.
        compile_one_filetype = [".py"],
        **kwargs
    )