# Output directory: elixir_make sets MIX_APP_PATH; fall back to local priv/
PRIV_DIR ?= $(if $(MIX_APP_PATH),$(MIX_APP_PATH)/priv,priv)
NIF_SO = $(PRIV_DIR)/prometheus_nif.so

# Erlang NIF headers
ERTS_INCLUDE_DIR ?= $(shell erl -noshell -eval "io:format(\"~s/erts-~s/include\", [code:root_dir(), erlang:system_info(version)])." -s init stop)

# Compiler settings
CXX ?= c++
CXXFLAGS = -std=c++17 -O2 -fPIC -fvisibility=hidden -Wall -Wextra -Wno-unused-parameter
CXXFLAGS += -I$(ERTS_INCLUDE_DIR)

# Platform-specific linker flags
UNAME_S := $(shell uname -s)
ifeq ($(UNAME_S),Darwin)
	LDFLAGS = -dynamiclib -undefined dynamic_lookup
else
	LDFLAGS = -shared
endif

# Sources — put .o in PRIV_DIR so each cross-compile target gets its own
NIF_SRC = c_src/prometheus_nif.cpp
NIF_OBJ = $(PRIV_DIR)/prometheus_nif.o

# Rust NIF settings
RUST_TARGET ?= $(shell rustc -Vv 2>/dev/null | grep host | cut -d' ' -f2)
RUST_NIF_DIR = $(PRIV_DIR)/native
RUST_NIF_SO = $(RUST_NIF_DIR)/tms_engine.so
CARGO_FLAGS = --release
ifneq ($(RUST_TARGET),)
	CARGO_FLAGS += --target $(RUST_TARGET)
	RUST_OUT_DIR = native/tms_engine/target/$(RUST_TARGET)/release
else
	RUST_OUT_DIR = native/tms_engine/target/release
endif

.PHONY: all clean

all: $(PRIV_DIR) $(NIF_SO) $(RUST_NIF_SO)

$(PRIV_DIR):
	mkdir -p $(PRIV_DIR)

# Always recompile — avoids stale cross-platform .o from Hex package or other arch
$(NIF_OBJ): .FORCE $(NIF_SRC)
	$(CXX) $(CXXFLAGS) -c -o $@ $(NIF_SRC)

$(NIF_SO): $(NIF_OBJ) | $(PRIV_DIR)
	$(CXX) $(LDFLAGS) -o $@ $(NIF_OBJ)

$(RUST_NIF_SO): .FORCE | $(PRIV_DIR)
	mkdir -p $(RUST_NIF_DIR)
	cd native/tms_engine && cargo build $(CARGO_FLAGS)
	cp $(RUST_OUT_DIR)/libtms_engine.so $(RUST_NIF_SO) 2>/dev/null || \
	cp $(RUST_OUT_DIR)/libtms_engine.dylib $(RUST_NIF_SO) 2>/dev/null || \
	(echo "ERROR: Rust NIF build failed — cargo not found or build error" && exit 1)

.FORCE:

clean:
	rm -f $(NIF_SO) $(NIF_OBJ)
	rm -f $(RUST_NIF_SO)
	cd native/tms_engine && cargo clean 2>/dev/null || true