CC ?= cc
CFLAGS ?= -std=c11 -march=native -pipe -Wall -Wextra -Wpedantic
OPENMP_FLAGS ?= -fopenmp
LDLIBS ?= -lm
ENABLE_PNG ?= 1
SPACETIME ?= minkowski
BUILD_TYPE ?= Release
ENABLE_HDR ?= 0
PSF_EVENT_SINK ?= 1
PSF_BACKEND ?= cpu
HIPCC ?= hipcc
HIP_CXXFLAGS ?= -std=c++17 -O2 -Wall -Wextra -Wpedantic

ifeq ($(BUILD_TYPE),Release)
BUILD_CFLAGS := -O2 -DNDEBUG
BUILD_CPPFLAGS :=
else ifeq ($(BUILD_TYPE),Debug)
BUILD_CFLAGS := -O0 -g3
BUILD_CPPFLAGS := -DGR_DEBUG
else
$(error Unknown BUILD_TYPE '$(BUILD_TYPE)'; choose Release or Debug)
endif

ifeq ($(ENABLE_PNG),1)
CPPFLAGS += -DENABLE_PNG
LDLIBS += -lpng
IMAGE_EXT := png
else
IMAGE_EXT := ppm
endif

COMMON_SOURCES := $(filter-out src/main.c src/dummy_psf.c src/fast_psf_fftw.c src/spacetime_minkowski.c src/spacetime_schwarzschild.c,$(wildcard src/*.c))
PROVIDER_SOURCE := src/spacetime_$(SPACETIME).c
BUILD_DIR := build/$(BUILD_TYPE)
TARGET_BASENAME := $(SPACETIME)_sky
OBJECT_DIR := $(BUILD_DIR)/obj/$(SPACETIME)
CORE_MINKOWSKI_SOURCES := $(COMMON_SOURCES) src/spacetime_minkowski.c

.PHONY: all backend clean run test hip-psf-test hip-psf-bench fast-psf-fftw-bench minkowski schwarzschild FORCE

ifneq ($(filter 0 1,$(PSF_EVENT_SINK)),$(PSF_EVENT_SINK))
$(error Unknown PSF_EVENT_SINK '$(PSF_EVENT_SINK)'; choose 0 or 1)
endif
BUILD_CPPFLAGS += -DFRAME_PSF_EVENT_SINK=$(PSF_EVENT_SINK)

ifeq ($(PSF_BACKEND),cpu)
RENDER_LINKER := $(CC)
ifeq ($(shell pkg-config --exists fftw3_omp && echo yes),yes)
CPU_FFTW_CPPFLAGS := -DFAST_PSF_FFTW $(shell pkg-config --cflags fftw3_omp)
CPU_FFTW_LDLIBS := $(shell pkg-config --libs fftw3_omp)
CPU_FFTW_SOURCES := src/fast_psf_fftw.c
BUILD_CPPFLAGS += $(CPU_FFTW_CPPFLAGS)
LDLIBS += $(CPU_FFTW_LDLIBS)
else
$(error PSF_BACKEND=cpu requires the FFTW OpenMP package 'fftw3_omp' (pkg-config --exists fftw3_omp). On Gentoo enable sci-libs/fftw[openmp].)
endif
else ifeq ($(PSF_BACKEND),hip)
RENDER_LINKER := $(HIPCC)
BUILD_CPPFLAGS += -DPSF_BACKEND_HIP
else ifeq ($(PSF_BACKEND),dummy)
RENDER_LINKER := $(CC)
BUILD_CPPFLAGS += -DPSF_BACKEND_DUMMY
else
$(error Unknown PSF_BACKEND '$(PSF_BACKEND)'; choose cpu, hip, or dummy)
endif

# `make test` builds and runs the CPU regression suite.  The dummy and hip
# backends do not build those binaries, so reject the goal explicitly instead of
# silently reusing a stale test binary left by an earlier CPU build.
ifneq ($(filter test test-reference-images,$(MAKECMDGOALS)),)
ifneq ($(PSF_BACKEND),cpu)
$(error make test requires PSF_BACKEND=cpu)
endif
endif

# psf-capture is a CPU producer diagnostic; the dummy and hip backends do not
# provide the producer/frame symbols it links.
ifneq ($(filter psf-capture,$(MAKECMDGOALS)),)
ifneq ($(PSF_BACKEND),cpu)
$(error psf-capture requires PSF_BACKEND=cpu)
endif
endif

ifeq ($(SPACETIME),minkowski)
BACKEND_CPPFLAGS := -DSPACETIME_MINKOWSKI
else ifeq ($(SPACETIME),schwarzschild)
BACKEND_CPPFLAGS := -DSPACETIME_SCHWARZSCHILD
else
$(error Unknown SPACETIME '$(SPACETIME)'; choose minkowski or schwarzschild)
endif

ifeq ($(ENABLE_HDR),1)
HDR_CPPFLAGS := -DENABLE_HDR_OUTPUT $(shell pkg-config --cflags cfitsio)
HDR_LDLIBS := $(shell pkg-config --libs cfitsio)
HDR_BUILD_TAG := hdr_sink$(PSF_EVENT_SINK)_$(PSF_BACKEND)
else ifeq ($(ENABLE_HDR),0)
HDR_BUILD_TAG := standard_sink$(PSF_EVENT_SINK)_$(PSF_BACKEND)
else
$(error Unknown ENABLE_HDR '$(ENABLE_HDR)'; choose 0 or 1)
endif

# Test binaries are namespaced by spacetime and build tag so that switching
# PSF_BACKEND/ENABLE_HDR/PSF_EVENT_SINK cannot silently reuse a stale binary
# built for a different backend.
TEST_OUT_DIR := $(OBJECT_DIR)/$(HDR_BUILD_TAG)
TEST_TARGET := $(TEST_OUT_DIR)/test_geodesic
FRAME_TEST_TARGET := $(TEST_OUT_DIR)/test_frame
SCHWARZSCHILD_TEST_TARGET := $(TEST_OUT_DIR)/test_schwarzschild
OBSERVER_TRACK_TEST_TARGET := $(TEST_OUT_DIR)/test_observer_track
CATALOG_PREFETCH_TEST_TARGET := $(TEST_OUT_DIR)/test_catalog_prefetch
HIP_PSF_TEST_TARGET := $(TEST_OUT_DIR)/test_hip_psf
HIP_PSF_BENCH_TARGET := $(TEST_OUT_DIR)/benchmark_hip_psf
CAMERA_TEST_TARGETS := $(TEST_OUT_DIR)/test_observer_minkowski $(TEST_OUT_DIR)/test_observer_schwarzschild
FAST_PSF_FFTW_TEST_TARGET := $(TEST_OUT_DIR)/test_fast_psf_fftw
FAST_PSF_FFTW_BENCH_TARGET := $(TEST_OUT_DIR)/benchmark_fast_psf_fftw

ifeq ($(PSF_BACKEND),hip)
TARGET := $(BUILD_DIR)/$(TARGET_BASENAME)_hip
else ifeq ($(PSF_BACKEND),dummy)
TARGET := $(BUILD_DIR)/$(TARGET_BASENAME)_dummy
else
TARGET := $(BUILD_DIR)/$(TARGET_BASENAME)
endif
RENDER_SOURCES := $(COMMON_SOURCES) $(PROVIDER_SOURCE) src/main.c
RENDER_SOURCES += $(CPU_FFTW_SOURCES)
ifeq ($(PSF_BACKEND),dummy)
RENDER_SOURCES += src/dummy_psf.c
endif
RENDER_OBJECTS := $(patsubst %.c,$(OBJECT_DIR)/$(HDR_BUILD_TAG)/%.o,$(RENDER_SOURCES))
ifeq ($(PSF_BACKEND),hip)
HIP_PSF_OBJECT := $(OBJECT_DIR)/$(HDR_BUILD_TAG)/src/hip_psf.o
RENDER_OBJECTS += $(HIP_PSF_OBJECT)
endif
RENDER_DEPS := $(RENDER_OBJECTS:.o=.d)

# With no explicit backend choice, all means every currently supported
# production spacetime backend. An explicit SPACETIME selects that backend,
# so `make SPACETIME=schwarzschild` remains the direct build command.
ifneq ($(filter command\ line environment environment\ override,$(origin SPACETIME)),)
all: backend
else
all: minkowski schwarzschild
endif

minkowski:
	$(MAKE) SPACETIME=minkowski ENABLE_HDR=$(ENABLE_HDR) backend

schwarzschild:
	$(MAKE) SPACETIME=schwarzschild ENABLE_HDR=$(ENABLE_HDR) backend

# Build exactly the selected backend/configuration, e.g.
# make SPACETIME=schwarzschild ENABLE_HDR=1 backend
backend: $(TARGET)

$(TARGET): $(RENDER_OBJECTS) FORCE | $(BUILD_DIR)
	$(RENDER_LINKER) $(BUILD_CFLAGS) $(OPENMP_FLAGS) $(RENDER_OBJECTS) $(LDLIBS) $(HDR_LDLIBS) -o $@

FORCE:

$(OBJECT_DIR)/$(HDR_BUILD_TAG)/%.o: %.c
	@mkdir -p $(dir $@)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(BACKEND_CPPFLAGS) $(HDR_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc -MMD -MP -c $< -o $@

$(BUILD_DIR):
	mkdir -p $@

$(OBJECT_DIR)/$(HDR_BUILD_TAG)/src/hip_psf.o: src/hip_psf.hip src/hip_psf.h src/optics.h
	@mkdir -p $(dir $@)
	$(HIPCC) $(HIP_CXXFLAGS) $(BUILD_CPPFLAGS) -Isrc -c $< -o $@

# This is a production-sink regression, not the removed float analytic spike.
# It requires PSF_BACKEND=hip and an actual HIP GPU agent at execution time.
ifeq ($(PSF_BACKEND),hip)
hip-psf-test: $(HIP_PSF_TEST_TARGET)
hip-psf-bench: $(HIP_PSF_BENCH_TARGET)

$(HIP_PSF_BENCH_TARGET): tests/benchmark_hip_psf.hip $(HIP_PSF_OBJECT) $(OBJECT_DIR)/$(HDR_BUILD_TAG)/src/optics.o | $(TEST_OUT_DIR)
	$(HIPCC) $(HIP_CXXFLAGS) $(OPENMP_FLAGS) -Isrc -x hip $< -x none $(filter-out $<,$^) $(LDLIBS) $(HDR_LDLIBS) -o $@

$(HIP_PSF_TEST_TARGET): tests/test_hip_psf.hip $(HIP_PSF_OBJECT) $(OBJECT_DIR)/$(HDR_BUILD_TAG)/src/optics.o | $(TEST_OUT_DIR)
	$(HIPCC) $(HIP_CXXFLAGS) $(OPENMP_FLAGS) -Isrc -x hip $< -x none $(filter-out $<,$^) $(LDLIBS) $(HDR_LDLIBS) -o $@
else
hip-psf-test hip-psf-bench:
	$(error HIP PSF checks require PSF_BACKEND=hip)
endif

run: $(TARGET)
	mkdir -p output/imgs
	./$(TARGET) --catalog assets/sky_grid_5deg.csv --output output/imgs/$(SPACETIME)_sky.$(IMAGE_EXT)

$(TEST_OUT_DIR): | $(BUILD_DIR)
	mkdir -p $@

$(TEST_TARGET): tests/test_geodesic.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(FRAME_TEST_TARGET): tests/test_frame.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(SCHWARZSCHILD_TEST_TARGET): tests/test_schwarzschild.c $(COMMON_SOURCES) src/spacetime_schwarzschild.c $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(OBSERVER_TRACK_TEST_TARGET): tests/test_observer_track.c $(COMMON_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(CATALOG_PREFETCH_TEST_TARGET): tests/test_catalog_prefetch.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(TEST_OUT_DIR)/test_observer_minkowski: tests/test_observer.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(TEST_OUT_DIR)/test_observer_schwarzschild: tests/test_observer.c $(COMMON_SOURCES) src/spacetime_schwarzschild.c $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -DSPACETIME_SCHWARZSCHILD -Isrc $^ $(LDLIBS) -o $@

$(FAST_PSF_FFTW_TEST_TARGET): tests/test_fast_psf_fftw.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

$(FAST_PSF_FFTW_BENCH_TARGET): tests/benchmark_fast_psf_fftw.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@

# The FFTW-vs-spatial test is meaningful only in the CPU PSF build.
ifneq ($(CPU_FFTW_SOURCES),)
FAST_PSF_FFTW_TEST_DEP := $(FAST_PSF_FFTW_TEST_TARGET)
FAST_PSF_FFTW_TEST_RUN := $(FAST_PSF_FFTW_TEST_TARGET)
else
FAST_PSF_FFTW_TEST_DEP :=
FAST_PSF_FFTW_TEST_RUN :=
endif

test: $(CAMERA_TEST_TARGETS) $(TEST_TARGET) $(FRAME_TEST_TARGET) $(SCHWARZSCHILD_TEST_TARGET) $(OBSERVER_TRACK_TEST_TARGET) $(CATALOG_PREFETCH_TEST_TARGET) $(FAST_PSF_FFTW_TEST_DEP)
	$(TEST_OUT_DIR)/test_observer_minkowski
	$(TEST_OUT_DIR)/test_observer_schwarzschild
	$(TEST_TARGET)
	$(FRAME_TEST_TARGET)
	$(SCHWARZSCHILD_TEST_TARGET)
	$(OBSERVER_TRACK_TEST_TARGET)
	$(CATALOG_PREFETCH_TEST_TARGET)
	$(FAST_PSF_FFTW_TEST_RUN)
	python3 tests/test_camera_cli.py $(BUILD_DIR) $(TEST_OUT_DIR)

fast-psf-fftw-bench: $(FAST_PSF_FFTW_BENCH_TARGET)

clean:
	rm -rf build

-include $(RENDER_DEPS)
include mk/reference_images.mk

# Test-only producer consumer: never linked into a renderer.
.PHONY: psf-capture
psf-capture: $(TEST_OUT_DIR)/capture_psf
$(TEST_OUT_DIR)/capture_psf: tests/capture_psf.c $(CORE_MINKOWSKI_SOURCES) $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $< $(filter-out src/frame.c,$(CORE_MINKOWSKI_SOURCES)) $(CPU_FFTW_SOURCES) $(LDLIBS) -o $@

.PHONY: hip-psf-replay
hip-psf-replay: $(TEST_OUT_DIR)/replay_psf
$(TEST_OUT_DIR)/replay_psf: tests/replay_psf.hip src/hip_psf.hip src/hip_psf.h src/optics.h $(OBJECT_DIR)/$(HDR_BUILD_TAG)/src/optics.o | $(TEST_OUT_DIR)
	$(HIPCC) $(HIP_CXXFLAGS) $(OPENMP_FLAGS) -Isrc -x hip $< -x none $(filter %.o,$^) $(LDLIBS) $(HDR_LDLIBS) -o $@

$(TEST_OUT_DIR)/make_psf_fixture: tests/make_psf_fixture.c src/optics.c src/optics.h $(CPU_FFTW_SOURCES) | $(TEST_OUT_DIR)
	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $< src/optics.c $(CPU_FFTW_SOURCES) $(LDLIBS) -o $@