# Compiler Flags
CC := gcc
CFLAGS := -g -Wall -Wextra -Werror -pedantic -fno-omit-frame-pointer

# Directory Variables 
LIBDIR := lib
OBJ := obj
INC := include
SRC := src
TEST := tests

# Platform Detection and Library Linking
ifeq ($(OS), Windows_NT)
    PLATFORM := win32
    PLATFORM_SRC := $(SRC)/windows_platform.c
    PLATFORM_OBJ := $(OBJ)/windows_platform.o
    PLATFORM_FLAGS := -D WIN32
    PLATFORM_LIBS := 
else
    UNAME_S := $(shell uname -s)
    ifeq ($(UNAME_S), Linux)
        PLATFORM := linux
        PLATFORM_SRC := $(SRC)/linux_platform.c
        PLATFORM_OBJ := $(OBJ)/linux_platform.o
        PLATFORM_FLAGS := -D LINUX
        PLATFORM_LIBS := -lX11 
    else ifeq ($(UNAME_S), Darwin)
        PLATFORM := macos
        PLATFORM_SRC := $(SRC)/macos_platform.c
        PLATFORM_OBJ := $(OBJ)/macos_platform.o
        PLATFORM_FLAGS := -D MACOS
        PLATFORM_LIBS := 
    else
        $(error Unsupported platform: $(UNAME_S))
    endif
endif


CFLAGS += $(PLATFORM_FLAGS)
# Filepath Pattern Matching
LIB := $(LIBDIR)/lib.a
# Exclude platform files from wildcard, add the correct one back in
SRCS := $(filter-out $(SRC)/windows_platform.c $(SRC)/linux_platform.c $(SRC)/macos_platform.c, \
        $(wildcard $(SRC)/*.c)) $(PLATFORM_SRC)
OBJS := $(patsubst $(SRC)/%.c, $(OBJ)/%.o, $(SRCS))
TESTS := $(wildcard $(TEST)/*.c)
TESTBINS := $(patsubst $(TEST)/%.c, $(TEST)/bin/%, $(TESTS))


# Commands must be labeled PHONY
.PHONY: all release clean test
# Compiler Release Flags 
release: CFLAGS := -Wall -Wextra -Werror -pedantic -fsanitize=address,undefined -fno-omit-frame-pointer -O2 -DNDEBUG $(PLATFORM_FLAGS)
release: clean $(LIB)


# Target for compilation.
all: $(LIB)
	@echo "Built for platform: $(PLATFORM)"
# Target / Dependencies
$(LIB): $(OBJS) | $(LIBDIR)
	$(RM) $(LIB)
	ar -cvrs $@ $^
$(OBJ)/%.o: $(SRC)/%.c $(SRC)/%.h | $(OBJ)
	$(CC) $(CFLAGS) -c $< -o $@
$(OBJ)/%.o: $(SRC)/%.c | $(OBJ)
	$(CC) $(CFLAGS) -c $< -o $@
$(TEST)/bin/%: $(TEST)/%.c $(LIB) | $(TEST)/bin
	$(CC) $(CFLAGS) $< $(LIB) $(PLATFORM_LIBS) -o $@

# Make directories if none. 
$(LIBDIR):
	mkdir $@
$(INC):
	mkdir $@
$(OBJ):
	mkdir $@
$(TEST)/bin:
	mkdir $@

# Run the tests in the bin folder and track results
test: $(LIB) $(TESTBINS)
	@SUCCESS=0; FAILURE=0; \
	RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; NC='\033[0m'; \
	for t in $(TESTBINS); do \
		NAME=$$(basename $$t); \
		START=$$(date +%s%N); \
		if $$t; then \
			RET=0; \
		else \
			RET=$$?; \
		fi; \
		END=$$(date +%s%N); \
		ELAPSED_NS=$$((END - START)); \
		ELAPSED_MS=$$((ELAPSED_NS / 1000000)); \
		if [ $$RET -eq 0 ]; then \
			printf "%-20s %bPASS%b (%b%4d ms%b)\n" "$$NAME" "$$GREEN" "$$NC" "$$YELLOW" "$$ELAPSED_MS" "$$NC"; \
			SUCCESS=$$((SUCCESS + 1)); \
		else \
			printf "%-20s %bFAIL%b (%b%4d ms%b)\n" "$$NAME" "$$RED" "$$NC" "$$YELLOW" "$$ELAPSED_MS" "$$NC"; \
			FAILURE=$$((FAILURE + 1)); \
		fi; \
	done; \
	printf "\nTests completed\n"; \
	printf "SUCCESS: %b%d%b\n" "$$GREEN" "$$SUCCESS" "$$NC"; \
	printf "FAILURE: %b%d%b\n" "$$RED" "$$FAILURE" "$$NC"; \
	test $$FAILURE -eq 0
	
clean:
	$(RM) -r $(LIBDIR) $(OBJ) $(TEST)/bin/