WEBRTC_BASE ?= .
WEBRTC_DIR ?= $(WEBRTC_BASE)
WEBRTC_VERSION ?= m79
WEBRTC_OUT ?= Release
WEBRTC_GN_ARGS ?= \
	is_debug=false \
	use_sysroot=false \
	rtc_include_tests=false \
	rtc_use_h264=true \
	rtc_use_x11=false \
	treat_warnings_as_errors=false \
	is_clang=false \
	use_custom_libcxx=false \
	use_rtti=true \
	$(WEBRTC_GN_ARGS_EXTRA)
WEBRTC_TARGETS ?= default $(WEBRTC_TARGETS_EXTRA)
WEBRTC_INCLUDES = \
	api audio base call common_audio common_video logging media modules p2p pc \
	system_wrappers rtc_base rtc_tools video third_party common_types.h \
	$(WEBRTC_INCLUDES_EXTRA)

WEBRTC_PLATFORM ?= POSIX

WEBRTC_FLAGS ?= \
	-I$(WEBRTC_BASE)/include \
	-I$(WEBRTC_DIR)/include -I$(WEBRTC_DIR)/include/webrtc \
	-I$(WEBRTC_DIR)/include/webrtc/third_party/abseil-cpp \
	-DWEBRTC_$(WEBRTC_PLATFORM)

WEBRTC_SETPATH = PATH=$(WEBRTC_DIR)/depot_tools:"$$PATH"
RTC_STAMP_DEPOT = $(WEBRTC_DIR)/depot_tools/.stamp
RTC_STAMP_REPO = $(WEBRTC_DIR)/webrtc-checkout/.stamp
RTC_STAMP_VERSION = $(WEBRTC_DIR)/webrtc-checkout/.stamps/stamp-$(WEBRTC_VERSION)
RTC_STAMP_COMPILE = $(WEBRTC_DIR)/webrtc-checkout/src/out/$(WEBRTC_OUT)/.stamp
RTC_STAMP_INCLUDES = $(WEBRTC_DIR)/include/webrtc/.stamp
RTC_STAMP_ALL = \
	$(RTC_STAMP_DEPOT) $(RTC_STAMP_REPO) $(RTC_STAMP_VERSION) \
	$(RTC_STAMP_COMPILE) $(RTC_STAMP_INCLUDES)

.PHONY: rtcall
rtc-all: \
		$(WEBRTC_DIR)/include/webrtc/.stamp \
		$(WEBRTC_DIR)/lib/libwebrtc.a

# Get depot_tools, which contains all the tools required to work with Google software
$(RTC_STAMP_DEPOT):
	rm -rf $(WEBRTC_DIR)/depot_tools
	git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git $(WEBRTC_DIR)/depot_tools
	touch $@

# Fetch the WebRTC project itself
$(RTC_STAMP_REPO): $(RTC_STAMP_DEPOT)
	rm -rf $(WEBRTC_DIR)/webrtc-checkout && mkdir $(WEBRTC_DIR)/webrtc-checkout
	#
	# Fetch webrtc, thit will take time...
	cd $(WEBRTC_DIR)/webrtc-checkout && $(WEBRTC_SETPATH) fetch --nohooks --no-history webrtc
	touch $@

# Check out the correct WebRTC branch/commit
$(RTC_STAMP_VERSION): $(RTC_STAMP_REPO)
	rm -rf $(WEBRTC_DIR)/webrtc-checkout/.stamps && mkdir $(WEBRTC_DIR)/webrtc-checkout/.stamps
	cd $(WEBRTC_DIR)/webrtc-checkout/src && git checkout branch-heads/$(WEBRTC_VERSION)
	#
	# Sync webrtc, this will take time...
	cd $(WEBRTC_DIR)/webrtc-checkout/src && $(WEBRTC_SETPATH) gclient sync -D --nohooks
	touch $@

# Compile
$(RTC_STAMP_COMPILE):
	cd $(WEBRTC_DIR)/webrtc-checkout/src && $(WEBRTC_SETPATH) gn gen out/$(WEBRTC_OUT) --args='$(WEBRTC_GN_ARGS)'
	cd $(WEBRTC_DIR)/webrtc-checkout/src && $(WEBRTC_SETPATH) ninja -C out/$(WEBRTC_OUT) $(WEBRTC_TARGETS)
	touch $@

# Includes
$(RTC_STAMP_INCLUDES): $(RTC_STAMP_VERSION)
	rm -rf $(WEBRTC_DIR)/include/webrtc && mkdir -p $(WEBRTC_DIR)/include/webrtc
	rsync -m --recursive --include='*/' --include='*.h' --exclude='*' \
		$(patsubst %,$(WEBRTC_DIR)/webrtc-checkout/src/%,$(WEBRTC_INCLUDES)) \
		$(WEBRTC_DIR)/include/webrtc
	touch $@

# Libraries
.PRECIOUS: $(WEBRTC_DIR)/webrtc-checkout/src/out/$(WEBRTC_OUT)/obj/%.a
$(WEBRTC_DIR)/webrtc-checkout/src/out/$(WEBRTC_OUT)/obj/%.a: $(RTC_STAMP_COMPILE)
	touch $@
$(WEBRTC_DIR)/lib/%.a: $(WEBRTC_DIR)/webrtc-checkout/src/out/$(WEBRTC_OUT)/obj/%.a
	@mkdir -p $(@D)
	cp $< $@

# Create distribution
WEBRTC_DIST_LIBS ?= libwebrtc.a $(WEBRTC_DIST_LIBS_EXTRA)
$(WEBRTC_DIR)/dist.tar.gz: $(patsubst %,$(WEBRTC_DIR)/lib/%,$(WEBRTC_DIST_LIBS)) $(RTC_STAMP_ALL)
	rm -f $@
	cd $(WEBRTC_DIR) && tar czf $(notdir $@) \
		include $(patsubst %,lib/%,$(WEBRTC_DIST_LIBS)) \
		$(patsubst $(WEBRTC_DIR)/%,%,$(RTC_STAMP_ALL))

.PHONY: rtc-dist
rtc-dist: $(WEBRTC_DIR)/dist.tar.gz

.PHONY: rtc-clean
rtc-clean:
	rm -rf $(WEBRTC_DIR)/include/webrtc $(WEBRTC_DIR)/lib

.PHONY: rtc-gn-clean
rtc-gn-clean: rtc-clean
	cd $(WEBRTC_DIR)/webrtc-checkout/src && $(WEBRTC_SETPATH) gn clean out/$(WEBRTC_OUT)
	rm -f $(RTC_STAMP_COMPILE)

.PHONY: rtc-clean-all
rtc-clean-all: rtc-clean
	rm -rf $(WEBRTC_DIR)/depot_tools $(WEBRTC_DIR)/webrtc-checkout

.PHONY: rtc-redo
rtc-redo:
	rm -f $(RTC_STAMP_COMPILE)

.PHONY: rtc-mock-stamps
rtc-mock-stamps:
	mkdir -p $(dir $(RTC_STAMP_DEPOT)) && touch $(RTC_STAMP_DEPOT)
	mkdir -p $(dir $(RTC_STAMP_REPO)) && touch $(RTC_STAMP_REPO)
	mkdir -p $(dir $(RTC_STAMP_VERSION)) && touch $(RTC_STAMP_VERSION)
	mkdir -p $(dir $(RTC_STAMP_COMPILE)) && touch $(RTC_STAMP_COMPILE)
	mkdir -p $(dir $(RTC_STAMP_INCLUDES)) && touch $(RTC_STAMP_INCLUDES)