text: # Copyright 2015 gRPC 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
  #
  #     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.
  
  """
  Bazel macros to declare gRPC libraries automatically generated from proto files.
  
  This file declares two macros:
  - objc_proto_library
  - objc_grpc_library
  """
  
  def _lower_underscore_to_upper_camel(str):
      humps = []
      for hump in str.split("_"):
          humps += [hump[0].upper() + hump[1:]]
      return "".join(humps)
  
  def _file_to_upper_camel(src):
      elements = src.rpartition("/")
      upper_camel = _lower_underscore_to_upper_camel(elements[-1])
      return "".join(elements[:-1] + [upper_camel])
  
  def _file_with_extension(src, ext):
      elements = src.rpartition("/")
      basename = elements[-1].partition(".")[0]
      return "".join(elements[:-1] + [basename, ext])
  
  def _protoc_invocation(srcs, flags):
      """Returns a command line to invoke protoc from a genrule, on the given
      sources, using the given flags.
      """
      protoc_command = "$(location //external:protoc) -I . "
      srcs_params = ""
      for src in srcs:
          srcs_params += " $(location %s)" % (src)
      return protoc_command + flags + srcs_params
  
  def objc_proto_library(name, srcs, visibility = None):
      """Declares an objc_library for the code generated by protoc from the given
      proto sources. This generated code doesn't include proto services.
      """
      h_files = []
      m_files = []
      for src in srcs:
          src = _file_to_upper_camel(src)
          h_files += [_file_with_extension(src, ".pbobjc.h")]
          m_files += [_file_with_extension(src, ".pbobjc.m")]
  
      protoc_flags = "--objc_out=$(GENDIR)"
  
      native.genrule(
          name = name + "_codegen",
          srcs = srcs + ["//external:protoc"],
          outs = h_files + m_files,
          cmd = _protoc_invocation(srcs, protoc_flags),
      )
      native.objc_library(
          name = name,
          hdrs = h_files,
          includes = ["."],
          non_arc_srcs = m_files,
          deps = ["//external:protobuf_objc"],
          visibility = visibility,
      )
  
  def objc_grpc_library(name, services, other_messages, visibility = None):
      """Declares an objc_library for the code generated by gRPC and protoc from the
      given proto sources (services and other_messages). The generated code doesn't
      include proto services of the files passed as other_messages.
      """
      objc_proto_library(name + "_messages", services + other_messages)
  
      h_files = []
      m_files = []
      for src in services:
          src = _file_to_upper_camel(src)
          h_files += [_file_with_extension(src, ".pbrpc.h")]
          m_files += [_file_with_extension(src, ".pbrpc.m")]
  
      protoc_flags = ("--grpc_out=$(GENDIR) --plugin=" +
                      "protoc-gen-grpc=$(location //external:grpc_protoc_plugin_objc)")
  
      native.genrule(
          name = name + "_codegen",
          srcs = services + [
              "//external:grpc_protoc_plugin_objc",
              "//external:protoc",
          ],
          outs = h_files + m_files,
          cmd = _protoc_invocation(services, protoc_flags),
      )
      native.objc_library(
          name = name,
          hdrs = h_files,
          includes = ["."],
          srcs = m_files,
          deps = [
              ":" + name + "_messages",
              "//external:proto_objc_rpc",
          ],
          visibility = visibility,
      )
  
  