cmake_minimum_required(VERSION 3.23)
project(proto LANGUAGES CXX)

find_program(PROTOC_EXECUTABLE protoc)
find_program(GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)

if(NOT PROTOC_EXECUTABLE)
    message(FATAL_ERROR "protoc not found! Install protobuf compiler")
endif()

if(NOT GRPC_CPP_PLUGIN_EXECUTABLE)
    message(FATAL_ERROR "grpc_cpp_plugin not found! Install gRPC with C++ plugin")
endif()

set(PROTO_FILES
    ${CMAKE_CURRENT_SOURCE_DIR}/messages.proto
    ${CMAKE_CURRENT_SOURCE_DIR}/services.proto
)

set(PROTO_OUT ${CMAKE_CURRENT_BINARY_DIR})

set(GENERATED_FILES
  ${PROTO_OUT}/messages.pb.h ${PROTO_OUT}/messages.pb.cc
  ${PROTO_OUT}/services.pb.h ${PROTO_OUT}/services.pb.cc
  ${PROTO_OUT}/services.grpc.pb.h ${PROTO_OUT}/services.grpc.pb.cc
)

set(PROTO_INCLUDES
  "-I${CMAKE_CURRENT_LIST_DIR}"
)

add_custom_command(
  OUTPUT ${GENERATED_FILES}
  COMMAND ${PROTOC_EXECUTABLE}
  ARGS
  --cpp_out=${PROTO_OUT}
  --grpc_out=${PROTO_OUT}
  --plugin=protoc-gen-grpc=${GRPC_CPP_PLUGIN_EXECUTABLE}
  ${PROTO_INCLUDES}
  ${PROTO_FILES}
  WORKING_DIRECTORY ${PROTO_OUT}
  DEPENDS ${PROTO_FILES}
  COMMENT "Generating protobuf files"
  COMMAND_EXPAND_LISTS
  VERBATIM
)

set_source_files_properties(${GENERATED_FILES} PROPERTIES GENERATED TRUE)

add_library(proto_interface INTERFACE ${GENERATED_FILES})