export OUT = $(PWD)/out

# TODO: calculate these using $(MAKE_HOST)
export ARCH = x86
export OS = lin
export BITS = 64
export ROOT = $(PWD)
export TMP = $(PWD)/tmp

ifneq ($(BITS),)
    export TARGET = $(ARCH).$(OS).$(BITS)
else
    export TARGET = $(ARCH).$(OS)
endif

export m4 = m4

moddirs = $(wildcard k*)
binaries = $(wildcard k*/*.exe.c)
functions = $(wildcard k*/*.fn.c) 
assemblies = $(wildcard k*/*.fn.$(TARGET).s)
binmods = $(sort $(dir $(binaries)))

# i'm sorry
collect = $(strip $(foreach dir,$(moddirs),$(wildcard $(dir)/*.$1)))
transform = $(strip $(foreach dir,$(moddirs),$(patsubst $(dir)/%.$1,$(subst @,$(dir),$2),$(wildcard $(dir)/*.$1))))

m-hdr-macs = $(call collect,h.m)
m-c-src-macs = $(call collect,c.m)
m-s-src-macs = $(call collect,$(TARGET).s.m)

m-c-sources = $(call transform,c.m,$(TMP)/@.%.c)
m-s-sources = $(call transform,$(TARGET).s.m,$(TMP)/@.%.$(TARGET).s)

m-headers = $(call transform,h.m,$(OUT)/k/%.h)
m-c-objects = $(call transform,c.m,$(OUT)/@.%.o)
m-s-objects = $(call transform,$(TARGET).s.m,$(OUT)/@.%.$(TARGET).o)

fnobjects = $(call transform,fn.c,$(OUT)/@.%.fn.o) \
            $(call transform,fn.c.m,$(OUT)/@.%.fn.o) \
            $(call transform,fn.$(TARGET).s,$(OUT)/@.%.fn.$(TARGET).o) \
            $(call transform,fn.$(TARGET).s.m,$(OUT)/@.%.fn.$(TARGET).o)

rtobjects = $(call transform,rt.c,$(OUT)/@.%.rt.o) \
            $(call transform,rt.c.m,$(OUT)/@.%.rt.o) \
            $(call transform,rt.$(TARGET).s,$(OUT)/@.%.rt.$(TARGET).o) \
            $(call transform,rt.$(TARGET).s.m,$(OUT)/@.%.rt.$(TARGET).o)

objects = $(fnobjects) $(rtobjects)

header-dir = /usr/include
lib-dir = /usr/lib

unix-oses = lin fbsd dar and
posix-oses = lin fbsd dar and hai mgw

ifeq ($(findstring $(OS),$(unix-oses)),$(OS))
    export UNIX = yes
    export POSIX = yes
else
    export UNIX = no
    ifeq ($(findstring $(OS),$(posix-oses)),$(OS))
        export POSIX = yes
	else
        export POSIX = no
	endif
endif

# include libgcc.a in gcc builds, just in case
ifeq ($(CC),gcc)
export COMPLIB = -lgcc
endif

all: $(OUT) defs obj tool lib.static $(OUT)/boot.o lib.shared
lib.static: defs obj $(OUT)/libk.a
lib.shared: defs obj $(OUT)/libk.so
obj: $(moddirs:%=%.obj) 
defs: $(moddirs:%=%.def) 
tool: $(OUT)/boot.o $(OUT)/libk.a $(binmods:%=%.tool) 
clean:
	rm -rf $(TMP) $(OUT)

install: all
	install -d $(header-dir)/k -o root -g wheel
	install $(OUT)/k/* $(header-dir)/k/ -o root -g wheel -m 0644
	install -d $(lib-dir)/k -o root -g wheel
	install $(OUT)/libk.a $(OUT)/libk.so $(OUT)/boot.o \
		$(lib-dir)/k/ -o root -g wheel -m 0644

uninstall: $(header-dir)/k $(lib-dir)/k
	rm -rf $^

lists = moddirs functions assemblies fnobjects rtobjects binaries binmods POSIX
dbg:
	@echo -e lists: $(foreach var, $(lists), "\\n - \\e[1m$(var)\\e[m = $($(var))")

%.obj: %/makefile $(TMP)/system_calls.h $(TMP)/system_calls.s $(OUT)
	cd $* && $(MAKE) obj

%.tool: %/makefile $(OUT)
	cd $* && $(MAKE) tool

%.dbg: %/makefile $(OUT)
	cd $* && $(MAKE) dbg

%.def: %/makefile $(TMP)/typesize.def $(OUT) $(OUT)/k
	cd $* && $(MAKE) def

.PRECIOUS: $(TMP)/system_calls.%
$(TMP)/system_calls.%: arch/makefile
	$(MAKE) -C arch $@

$(TMP)/typesize.def: arch/makefile $(TMP)
	$(MAKE) -C arch $@

$(OUT)/libk.so: $(fnobjects) 
	ld -shared $(COMPLIB) -o $@ $^
	@# $(CC) -shared -fPIC -nostdlib $(COMPLIB) -o $@ $(OUT)/*.o

$(OUT)/boot.o: $(rtobjects)
	ld -r $^ -o $(OUT)/boot.o

$(OUT)/libk.a: $(fnobjects) $(rtobjects)
	@# using `ar rc` and ranlib here instead of
	@# `ar rcs` in case `ar` isn't the GNU version
	ar rc $@ $^
	ranlib $@

$(OUT) $(OUT)/k $(TMP):
	mkdir -p $@
