.DEFAULT_GOAL := engine

# Modules listed in dependency order
MODULE_NAMES := entity tilemap world input physics renderer assets engine mixer sound animation ai scene-loader
OBJECT_FILES := $(patsubst %,bin/%.o,$(MODULE_NAMES))

DEMO_NAMES := platformer shmup topdown audio sandbox
DEMO_BINS  := $(patsubst %,bin/demo-%,$(DEMO_NAMES))

UNIT_NAMES := $(patsubst %,downstroke-%,$(MODULE_NAMES))
USES_FLAGS := $(patsubst %,-uses %,$(UNIT_NAMES))

# Build all engine modules
engine: $(OBJECT_FILES)

bin:
	@mkdir -p $@

# Explicit inter-module dependencies
bin/entity.o:
bin/tilemap.o:
bin/world.o: bin/entity.o bin/tilemap.o
bin/input.o: bin/entity.o
bin/physics.o: bin/entity.o bin/world.o bin/tilemap.o
bin/renderer.o: bin/entity.o bin/tilemap.o bin/world.o
bin/assets.o:
bin/engine.o: bin/renderer.o bin/world.o bin/input.o bin/assets.o
bin/mixer.o:
bin/sound.o: bin/mixer.o
bin/animation.o: bin/entity.o bin/world.o
bin/ai.o: bin/entity.o bin/world.o
bin/scene-loader.o: bin/world.o bin/tilemap.o bin/assets.o bin/engine.o

# Pattern rule: compile each module as a library unit
bin/%.o: %.scm | bin
	csc -c -J -unit downstroke-$* $*.scm -o bin/$*.o -I bin
	@if [ -f downstroke-$*.import.scm ]; then mv downstroke-$*.import.scm bin/; fi

.PHONY: clean test engine demos

clean:
	rm -rf bin
	rm -f *.import.scm
	rm -f *.log

test:
	@echo "Running unit tests..."
	@csi -s tests/entity-test.scm
	@csi -s tests/world-test.scm
	@csi -s tests/tilemap-test.scm
	@csi -s tests/physics-test.scm
	@csi -s tests/input-test.scm
	@csi -s tests/renderer-test.scm
	@csi -s tests/assets-test.scm
	@csi -s tests/engine-test.scm
	@csi -s tests/animation-test.scm
	@csi -s tests/ai-test.scm
	@csi -s tests/scene-loader-test.scm

demos: engine $(DEMO_BINS)

bin/demo-%: demo/%.scm $(OBJECT_FILES) | bin
	csc demo/$*.scm $(OBJECT_FILES) -o bin/demo-$* -I bin $(USES_FLAGS) -L -lSDL2_mixer