Start work on protobuf files and code generation

CMakeLists.txt

@@ -1,5 +1,6 @@
 cmake_minimum_required(VERSION 3.23)
 project(chat LANGUAGES CXX)
 
+add_subdirectory(proto)
 add_subdirectory(server)
 add_subdirectory(client)

proto/CMakeLists.txt

@@ -0,0 +1,50 @@
+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})

proto/messages.proto

@@ -0,0 +1,8 @@
+syntax = "proto3";
+
+package chat;
+
+message chatMsg {
+  string userid = 1;
+  string message = 2;
+}

proto/services.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package chat;
+
+import "messages.proto";
+
+service Chat {
+  rpc sendMsg(stream chatMsg) returns (stream chatMsg) {}
+}