#
# $Id$
#
# Generate source and header files from protobuf spec, typically for
# use with gRPC.
#
# (NOTE: hard-wired for the C++ Toolkit directory structure.)
#

-include $(builddir)/Makefile.mk

SRCDIR = $(top_srcdir)/src/$(MODULE_PATH)
INCLUDEDIR = $(top_srcdir)/include/$(MODULE_PATH)

SPEC = $(MODULE_PATH)/$(MODULE_ASN) # sic
FILES = $(MODULE).files
comma = ,
# empty =
# space = $(empty) $(empty)
# IMPDIRS = $(subst $(space),:,$(dir $(IMPDEPS)))
# PROTOC_FLAGS = -I$(SRCDIR):$(IMPDIRS):$(subst $(comma),:,$(MODULE_SEARCH))
PROTOC_FLAGS = -I.:$(subst $(comma),:,$(MODULE_SEARCH))

PROTOBUF_BIN = @PROTOBUF_BIN@
GRPC_BIN = @GRPC_BIN@
PROTOC = $(PROTOBUF_BIN)/protoc
GRPC_CPP_PLUGIN = $(GRPC_BIN)/grpc_cpp_plugin

ifneq "" "$(wildcard $(PROTOC))"
  PROTOC_VERSION := $(lastword $(shell $(PROTOC) --version))
endif
VERSION_MARKER_BASE = $(MODULE).using-protoc-
VERSION_MARKER = $(VERSION_MARKER_BASE)$(PROTOC_VERSION)

CAN_MOCK := $(shell grep generate_mock_code $(GRPC_CPP_PLUGIN))
ifneq "" "$(CAN_MOCK)"
   MOCK_OPTION = generate_mock_code=true:
   MOCK_HEADER = $(MODULE)_mock.grpc.pb.h
endif

GRPC_FILES = $(MODULE).grpc.pb.cc $(INCLUDEDIR)/$(MODULE).grpc.pb.h \
             $(MOCK_HEADER:%=$(INCLUDEDIR)/%)

DEPS = $(MODULE_ASN) $(PROTOC) $(MODULE).module $(IMPDEPS) $(VERSION_MARKER)

all: sources

all_files: sources

sources: $(FILES)

clean_sources:
	-$(RM) $(FILES) *.pb.cpp *.pb.h $(VERSION_MARKER_BASE)*

purge_sources:
	-$(RM) $(FILES) *.pb.[ch]* $(INCLUDEDIR)/*.pb.h* \
	    $(VERSION_MARKER_BASE)*

purge_all_sources:
	-$(RM) $(FILES) *.pb.[ch]* $(INCLUDEDIR)/*.pb.h* \
	    $(VERSION_MARKER_BASE)*

purge_all_files:
	-$(RM) $(FILES) *.pb.[ch]* $(INCLUDEDIR)/*.pb.h*

ifneq "" "$(wildcard $(PROTOC))"
$(FILES): $(MODULE).pb.cc $(INCLUDEDIR)/$(MODULE).pb.h $(GRPC_FILES)
	$(RM) $(MODULE).pb.cpp $(MODULE).grpc.pb.cpp
	@$(TOUCH) $@
else
$(FILES): $(GRPC_FILES)
	@echo Warning: Skipping code generation for $(MODULE_ASN) >&2
	@echo because protoc is unavailable here. >&2
	@$(TOUCH) $(MODULE).pb.cc $(INCLUDEDIR)/$(MODULE).pb.h
endif

$(MODULE).pb.cc $(MODULE).pb.h: $(DEPS)
	cd $(top_srcdir)/src  &&  $(PROTOC) $(PROTOC_FLAGS) --cpp_out=. $(SPEC)

ifneq "" "$(wildcard $(GRPC_CPP_PLUGIN))"
$(MODULE).grpc.pb.cc $(MODULE).grpc.pb.h $(MOCK_HEADER): \
    $(DEPS) $(GRPC_CPP_PLUGIN)
	cd $(top_srcdir)/src  &&  $(PROTOC) $(PROTOC_FLAGS) \
            --grpc_out=$(MOCK_OPTION). \
	    --plugin=protoc-gen-grpc=$(GRPC_CPP_PLUGIN) $(SPEC)
else
$(GRPC_FILES):
	@$(TOUCH) $(GRPC_FILES)
endif

$(INCLUDEDIR)/%.pb.h: %.pb.cc # not .h, to avoid duplicate protoc runs
	$(MKDIR) -p $(INCLUDEDIR)
	/bin/mv -f $*.pb.h $@

$(INCLUDEDIR)/%_mock.grpc.pb.h: $(INCLUDEDIR)/%.grpc.pb.h
	/bin/mv -f $*_mock.grpc.pb.h $@

$(MODULE).module:
	@$(TOUCH) $@

$(VERSION_MARKER): $(builddir)/Makefile.protobuf
	@-$(RM) $(VERSION_MARKER_BASE)*
	@$(TOUCH) $@