BUILD_DIR_NAME = _build
COMPILED_DIR_NAME = _compiled

USER_INCLUDE_DIR := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/include
USER_LIB_DIR     := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/lib
USER_UTILS_DIR   := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin-utils
USER_TESTS_DIR   := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin-tests
USER_BIN_DIR     := $(OUTPUT_DIR)/$(COMPILED_DIR_NAME)/bin
USER_BUILD_DIR   := $(OUTPUT_DIR)/$(BUILD_DIR_NAME)/user
LINK_BUILD_DIR   := $(OUTPUT_DIR)/$(BUILD_DIR_NAME)/link

USER_OBJS_DIR = $(USER_BUILD_DIR)/$(RELATIVE_DIR)
KERN_OBJS_DIR = $(KERN_BUILD_DIR)/$(RELATIVE_DIR)
OMK_WORK_DIR  = $(USER_OBJS_DIR)

strip_out = $(patsubst $(OUTPUT_DIR)/%,%,$(1))
repl_out  = $(patsubst $(OUTPUT_DIR)/%,$$(OUTPUT_DIR)/%,$(1))

.PHONY: FORCE

#####################
# Build pseudo-pass #
#####################

rule_targets   = $($(1)_targets)
rule_deps      = $($(1)_deps)
rule_quiet_cmd = $($(1)_quiet_cmd)
rule_cmd       = $($(1)_cmd)

# Usage: $(call build_rule,<target>)
define build_rule
$(rule_target): $(rule_deps)	# TODO: dep on .cmd file
	@$(QUIET_CMD_ECHO) "  "$(rule_quiet_cmd) "$$(call strip_out,$$(@))"
	$(Q)$(rule_cmd)
endef

# TODO: Include target.omk only in the subtree
-include $(shell true; find $(USER_BUILD_DIR) -name '*.target.omk') # `true' is a hack for MinGW
-include $(shell true; find $(USER_BUILD_DIR) -name '*.var.omk') # `true' is a hack for MinGW

$(foreach target,$(minor_targets),$(eval $(call build_rule,$(target))))

.PHONY: build-pseudo-pass
build-pseudo-pass: $(foreach target,$(major_targets),$(target))

################
# Prepare pass #
################

$(eval $(call omk_pass_template,prepare-pass,$(USER_OBJS_DIR),,always))

var_omk_file = $(OMK_WORK_DIR)/$(notdir $(1)).var.omk
var_omk_target = $(1:$(OUTPUT_DIR)/%=%)

target_omk_file = $(OMK_WORK_DIR)/$(notdir $(1)).target.omk

###
# prepare is used to generate .var.omk files during prepare-pass.
# All paths in this file should be relative to $(OUTPUT_DIR)
# Usage: $(call prepare,<target-name>,<targets>,<deps>,<quiet_cmd>,<cmd>)
define prepare
prepare-pass-local: $(var_omk_file)

$(var_omk_file): FORCE
	$(Q)echo 'minor_targets += $(var_omk_target)' > $$@.tmp; \
	    echo '$(var_omk_target)_targets = $$(call strip_out,$(2))' >> $$@.tmp; \
	    echo '$(var_omk_target)_deps += $$(call strip_out,$(3))' >> $$@.tmp; \
	    echo '$(var_omk_target)_quiet_cmd = $(4)' >> $$@.tmp; \
	    echo '$(var_omk_target)_cmd = $$(call repl_out,$(5))' >> $$@.tmp; \
	if cmp -s $$@.tmp $$@; then rm $$@.tmp; else mv $$@.tmp $$@; fi
endef

define target
prepare-pass-local: $(var_omk_file)
$(target_omk_file): FORCE
	$(Q)echo 'major_targets += $(var_omk_target)' > $$@
endef

############
# Programs #
############

# Syntax: $(call compile_c_o_template,<source>,<target>,<additional c-flags>)
define compile_c_o_template

$(2): $(1) $$(GEN_HEADERS)
	@$(QUIET_CMD_ECHO) "  CC      $$@"
	$(Q) if $$(c_o_COMPILE) $$(CC_DEPFLAGS) $(3) -o $$@ -c $$< ; \
	then mv -f "$$@.d.tmp" "$$@.d" ; \
	else rm -f "$$@.d.tmp" ; exit 1; \
	fi
endef


# Usage: $(call program_template,<executable-name>,<bin|utils|test>)
define program_template
$(1)_OBJS += $$(patsubst %.c,%.o,$$(filter %.c,$$($(1)_SOURCES)))
$(1)_OBJS := $$(addprefix $(USER_OBJS_DIR),$$(sort $$($(1)_OBJS:%/=%)))

USER_OBJS  += $$($(1)_OBJS)
USER_SOURCES += $$($(1)_SOURCES)


program_targets = $(USER_BIN_DIR)/$(1)$(EXE_SUFFIX)
program_deps = $$($(1)_OBJS) $$($(1)_LIBS)
program_cmd = $$(if $$(filter %.cc,$$($(1)_SOURCES)),$$(CXX),$$(CC)) \
	$$($(1)_OBJS) $$($(1)_LIBS:%=-l%) $$(LOADLIBES) $$(LDFLAGS) -Wl,-rpath-link,$(USER_LIB_DIR) \
	-Wl,-Map,$(USER_OBJS_DIR)/$(1).exe.map -o $$$$@

$(call prepare,\
	$(2)_PROGRAMS_$(1),\
	$$(program_targets),\
	$$(program_deps),\
	"LINK    ",\
	$$(program_cmd))
endef

c_o_cmd := set -e; cd $$(dir $$@); \
	if $$(c_o_COMPILE) $$(CC_DEPFLAGS) -o $$@ -c $$< ; \
	then mv -f "$$@.d.tmp" "$$@.d" ; \
	else rm -f "$$@.d.tmp" ; \
	fi


$(foreach prog,$(bin_PROGRAMS),$(eval $(call program_template,$(prog),bin)))
$(foreach src,$(filter %.c,$(USER_SOURCES)),$(eval $(call prepare,\
	$(USER_OBJS_DIR)/$(src:%.c=%.o),\
	$(USER_OBJS_DIR)/$(src:%.c=%.o),\
	$(SOURCES_DIR)/$(src),\
	"CC      ",\
	$(c_o_cmd))))

default: prepare-pass