# Copyright 2021 The Pigweed Authors
#
# 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
#
#     https://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.

import("//build_overrides/pigweed.gni")

import("$dir_pw_build/python.gni")
import("$dir_pw_build/target_types.gni")
import("$dir_pw_protobuf_compiler/proto.gni")
import("nanopb.gni")

# This file defines a GN source_set for an external installation of nanopb.
# To use, checkout the nanopb source into a directory, then set the build arg
# dir_pw_third_party_nanopb to point to that directory. The nanopb library
# will be available in GN at "$pw_external_nanopb".
if (dir_pw_third_party_nanopb != "") {
  config("includes") {
    include_dirs = [ dir_pw_third_party_nanopb ]
  }

  config("disable_warnings") {
    cflags = [
      # Fixed in upstream (https://github.com/nanopb/nanopb/pull/1022), but that
      # PR is not yet in any released version of nanopb (as of 0.4.9.1).
      "-Wno-switch-enum",
    ]
    visibility = [ ":*" ]
  }

  pw_source_set("nanopb") {
    public_configs = [
      ":disable_warnings",
      ":includes",
    ]
    public = [
      "$dir_pw_third_party_nanopb/pb.h",
      "$dir_pw_third_party_nanopb/pb_common.h",
      "$dir_pw_third_party_nanopb/pb_decode.h",
      "$dir_pw_third_party_nanopb/pb_encode.h",
    ]
    public_deps = [ pw_third_party_nanopb_CONFIG ]
    sources = [
      "$dir_pw_third_party_nanopb/pb_common.c",
      "$dir_pw_third_party_nanopb/pb_decode.c",
      "$dir_pw_third_party_nanopb/pb_encode.c",
    ]
  }

  pw_proto_library("proto") {
    strip_prefix = "$dir_pw_third_party_nanopb/generator/proto"
    sources = [ "$dir_pw_third_party_nanopb/generator/proto/nanopb.proto" ]
    python_module_as_package = "nanopb_pb2"
  }

  # Generates nanopb_pb2.py, which is needed to compile protobufs with Nanopb.
  pw_python_script("generate_nanopb_proto") {
    sources = [ "generate_nanopb_proto.py" ]
    pylintrc = "$dir_pigweed/.pylintrc"
    mypy_ini = "$dir_pigweed/.mypy.ini"
    ruff_toml = "$dir_pigweed/.ruff.toml"

    # Path to protoc binary. This variable is relative to the build directory,
    # so it must be rebased as a source-tree-absolute path.
    _protoc_binary_path =
        "//" +
        rebase_path(pw_protobuf_compiler_PROTOC_BINARY, "//", root_build_dir)

    if (host_os == "win") {
      if (get_path_info(_protoc_binary_path, "extension") != "exe" &&
          get_path_info(_protoc_binary_path, "extension") != "bat") {
        _protoc_binary_path += ".exe"
      }
    }
    inputs = [
      "$dir_pw_third_party_nanopb/pb.h",
      "$dir_pw_third_party_nanopb/pb_common.h",
      "$dir_pw_third_party_nanopb/pb_decode.h",
      "$dir_pw_third_party_nanopb/pb_encode.h",
      "$dir_pw_third_party_nanopb/pb_common.c",
      "$dir_pw_third_party_nanopb/pb_decode.c",
      "$dir_pw_third_party_nanopb/pb_encode.c",
      "$dir_pw_third_party_nanopb/generator/nanopb_generator.py",
      "$dir_pw_third_party_nanopb/generator/proto/google/protobuf",
      "$dir_pw_third_party_nanopb/generator/proto/google/protobuf/descriptor.proto",
      "$dir_pw_third_party_nanopb/generator/proto/__init__.py",
      "$dir_pw_third_party_nanopb/generator/proto/nanopb.proto",
      "$dir_pw_third_party_nanopb/generator/proto/_utils.py",
      "$dir_pw_third_party_nanopb/generator/protoc-gen-nanopb",
      "$dir_pw_third_party_nanopb/generator/nanopb_generator.py2",
      "$dir_pw_third_party_nanopb/generator/protoc-gen-nanopb-py2",
      "$dir_pw_third_party_nanopb/generator/protoc",
      "$dir_pw_third_party_nanopb/generator/protoc-gen-nanopb.bat",
      "$dir_pw_third_party_nanopb/generator/protoc.bat",
      _protoc_binary_path,
    ]
    action = {
      args = [
        "--nanopb-root=" +
            rebase_path(dir_pw_third_party_nanopb, root_build_dir),
        "--nanopb-pb2-dir=" +
            rebase_path(pw_protobuf_compiler_INTERNAL_NANOPB_PB2_DIR,
                        root_build_dir,
                        root_gen_dir),

        # This is spelled a little weirdly because
        # `pw_protobuf_compiler_PROTOC_BINARY` often points to a GN-absolute
        # path like //.environment/packages/protobuf/protoc rather than the
        # originally intended build-root relative path of
        # ../.environment/packages/protobuf/protoc. This basically says
        # "make GN-absolute paths relative to the build root, and don't modify
        # paths that are already relative to the build root."
        "--protoc-binary=" + rebase_path(pw_protobuf_compiler_PROTOC_BINARY,
                                         root_build_dir,
                                         root_build_dir),
      ]

      outputs =
          [ "$pw_protobuf_compiler_INTERNAL_NANOPB_PB2_DIR/nanopb_pb2.py" ]
    }
  }
} else {
  group("nanopb") {
  }
  pw_python_group("generate_nanopb_proto") {
  }
}

config("disable_error_messages_config") {
  defines = [ "PB_NO_ERRMSG=1" ]
}

pw_source_set("disable_error_messages") {
  public_configs = [ ":disable_error_messages_config" ]
}