USR_PREFIX = /usr
LOCAL_PREFIX = $(USR_PREFIX)/local
BIN = /bin
SBIN = /sbin
DEV = /dev

EXTRA_CPP_FLAGS = 
# see configurable-definitions

_LB = $(LOCAL_PREFIX)$(BIN)
_UB = $(USR_PREFIX)$(BIN)
_SB = $(BIN)
_LS = $(LOCAL_PREFIX)$(SBIN)
_US = $(USR_PREFIX)$(SBIN)
_SS = $(SBIN)

AUTH = pam
TTY_GROUP = tty
DEFAULT_HOME = /
DEFAULT_SH = sh
DEFAULT_SHELL = $(BIN)/$(DEFAULT_SH)
DEFAULT_TERM = dumb
VCS = $(DEV)/vcs
VCSA = $(DEV)/vcsa
PATH = $(_LB):$(_UB):$(_SB)
PATH_ROOT = $(_LS):$(_LB):$(_US):$(_UB):$(_SS):$(_SB)

auth_none = 0
auth_crypt = 1
auth_pam = 2

H = \#
VCS_LEN = $(shell vcs="$(VCS)" ; echo "$${$(H)vcs}")
VCSA_LEN = $(shell vcsa="$(VCSA)" ; echo "$${$(H)vcsa}")

STR_DEFS = TTY_GROUP DEFAULT_HOME DEFAULT_SH DEFAULT_SHELL DEFAULT_TERM PATH PATH_ROOT VCS VCSA
VRB_DEFS = VCS_LEN VCSA_LEN

STR_CPPFLAGS = $(foreach D, $(STR_DEFS), -D'$(D)="$($(D))"')
VRB_CPPFLAGS = $(foreach D, $(VRB_DEFS), -D'$(D)=$($(D))') -DAUTH=$(auth_$(AUTH))

OPTIMISE = -Os
CPPFLAGS = $(EXTRA_CPP_FLAGS) $(STR_CPPFLAGS) $(VRB_CPPFLAGS)
CFLAGS = -std=gnu99 -Wall -Wextra
LDFLAGS =
ifeq ($(AUTH),crypt)
LDFLAGS += -lcrypt
endif
ifeq ($(AUTH),pam)
LDFLAGS += -lpam
endif

CC_FLAGS = $(CPPFLAGS) $(CFLAGS) $(OPTIMISE)
LD_FLAGS = $(LDFLAGS) $(CFLAGS) $(OPTIMISE)

SRC = cerberus passphrase quit security login
ifneq ($(AUTH),none)
SRC += auth/$(AUTH)
endif
OBJ = $(foreach S, $(SRC), obj/$(S).o)


.PHONY: all
all: bin/cerberus


bin/cerberus: $(OBJ)
	@mkdir -p bin
	$(CC) $(LD_FLAGS) -o "$@" $^


obj/cerberus.o: $(foreach H, $(SRC), src/$(H).h) src/auth.h
obj/%.o: src/%.c src/%.h src/config.h
	@mkdir -p "$(shell dirname "$@")"
	$(CC) $(CC_FLAGS) -o "$@" -c "$<"


.PHONY: clean
clean:
	-rm -r bin obj