ifeq ($(NDK),)
$(error Must export NDK location before building for Android)
endif
NDK_ROOT:=$(NDK)
#NDK_LOG:=1
include $(NDK)/build/core/init.mk

TOOLCHAIN:=$(foreach chain, $(NDK_ALL_TOOLCHAINS), $(if $(findstring arm, $(chain)), $(chain), ))
# Filter out clang
TEMP_TC := $(foreach chain, $(TOOLCHAIN), $(if $(findstring clang, $(chain)), , $(chain)))
ifneq ($(strip $(TEMP_TC)),)
	TOOLCHAIN := $(TEMP_TC)
endif
# use freshmost compiler
TOOLCHAIN:=$(lastword $(TOOLCHAIN))

TOOLCHAIN_ARCH:=
-include $(NDK)/build/core/toolchains/$(TOOLCHAIN)/config.mk
-include $(NDK)/build/core/toolchains/$(TOOLCHAIN)/setup.mk

ifeq ($(TOOLCHAIN_ARCH),arm)

TOOL_PATH:=$(NDK)/toolchains/llvm/prebuilt/linux-x86_64/bin
CROSS_PREFIX:=$(TOOL_PATH)/$(TOOLCHAIN_NAME)-

#Now it's time to decide upon clang/clang++
CLANG_NAME:=$(subst arm-,armv7a-,$(TOOLCHAIN_NAME))
CLANG_NUM:=$(shell mi=256; for i in `seq 24 $$mi`; do [ -e $(TOOL_PATH)/$(CLANG_NAME)$$i-clang ] && [ $$i -le $$mi ] && mi=$$i; done; echo $$mi)
CXX:=$(TOOL_PATH)/$(CLANG_NAME)$(CLANG_NUM)-clang++
CC:=$(TOOL_PATH)/$(CLANG_NAME)$(CLANG_NUM)-clang

#CROSS_FLAGS:=--sysroot=$(NDK)/sysroot \
#			 -I$(ROOT)/gen/cross \
#			 -I$(NDK)/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/c++/v1

CROSS_FLAGS:=--sysroot=$(NDK)/toolchains/llvm/prebuilt/linux-x86_64/sysroot \
			 -I$(ROOT)/gen/cross

else
#TOOLCHAIN_ARCH

ifeq ($(HOST_TAG64),)
HOST_TAG64:=linux-x86
endif
NDK_TOOLCHAIN_VERSION:=$(shell echo $(TOOLCHAIN_DIR) | awk -F - '{print $$NF;}')

CROSS_PLATFORM:=$(NDK)/platforms
ALEVEL:=$(shell for i in `seq 256`; do [ -d $(CROSS_PLATFORM)/android-$${i} ] && adir=$${i}; done; echo $${adir})
CROSS_PLATFORM:=$(CROSS_PLATFORM)/android-$(ALEVEL)/arch-arm

CROSS_PREFIX:=$(NDK)/toolchains/$(TOOLCHAIN_DIR)/prebuilt/$(HOST_TAG64)/bin/arm-linux-androideabi-

CXX:=$(CROSS_PREFIX)g++
CC:=$(CROSS_PREFIX)gcc

CROSS_FLAGS=--sysroot=$(CROSS_PLATFORM) \
			-I$(CROSS_PLATFORM)/usr/include -I$(ROOT)/gen/cross \
			-I$(NDK)/sources/cxx-stl/gnu-libstdc++/$(NDK_TOOLCHAIN_VERSION)/include \
			-I$(NDK)/sources/cxx-stl/gnu-libstdc++/$(NDK_TOOLCHAIN_VERSION)/libs/armeabi/include

endif
#TOOLCHAIN_ARCH


AR:=$(CROSS_PREFIX)ar
AS:=$(CROSS_PREFIX)as
LD:=$(CROSS_PREFIX)ld
NM:=$(CROSS_PREFIX)nm
OBJCOPY:=$(CROSS_PREFIX)objcopy
OBJDUMP:=$(CROSS_PREFIX)objdump
RANLIB:=$(CROSS_PREFIX)ranlib
STRIP:=$(CROSS_PREFIX)strip

export CXX
export CC
export AR

export CROSS_FLAGS

COMMON_FLAGS=-ggdb -DFB_SEND_FLAGS=MSG_NOSIGNAL -DLINUX -DANDROID -DARM -pipe -MMD -fPIC -fmessage-length=0 \
			 -I$(ROOT)/extern/libtommath -I$(ROOT)/extern/libtomcrypt/src/headers \
			 $(CROSS_FLAGS) -fsigned-char

OPTIMIZE_FLAGS=-fno-omit-frame-pointer
WARN_FLAGS=-Wall -Wno-switch -Wno-parentheses -Wno-unknown-pragmas -Wno-unused-variable

PROD_FLAGS=$(COMMON_FLAGS) $(OPTIMIZE_FLAGS)
DEV_FLAGS=$(COMMON_FLAGS) $(WARN_FLAGS)

CROSS_CONFIG=android.arme

LDFLAGS += --sysroot=$(CROSS_PLATFORM) -L$(NDK)/sources/cxx-stl/gnu-libstdc++/$(NDK_TOOLCHAIN_VERSION)/libs/armeabi \
	-L$(NDK)/sources/cxx-stl/gnu-libstdc++/libs/armeabi
DroidLibs := -lm -ldl $(DECLIB) $(RE2LIB)
UDR_SUPPORT_LIBS :=

LINK_LIBS = $(DroidLibs)
SO_LINK_LIBS = $(DroidLibs)

EXE_LINK_OPTIONS= $(LDFLAGS) $(UNDEF_FLAGS) $(LIB_PATH_OPTS) $(LINK_EMPTY_SYMBOLS) -pie
LIB_LINK_OPTIONS= $(LDFLAGS) -shared

UNICODE_DIR := $(shell dirname `find /usr/include -name ucnv.h`)
UNICODE_DIR := $(filter %unicode, $(UNICODE_DIR))
UNICODE_DIR := $(firstword $(UNICODE_DIR))
ifndef UNICODE_DIR
	$(error ERROR while locating ICU include directory, probably missing ucnv.h)
endif

.PHONY:	prerequisites
prerequisites: $(ROOT)/gen/cross/unicode

$(ROOT)/gen/cross/unicode:
	echo $(UNICODE_DIR)
	rm -rf $(ROOT)/gen/cross
	mkdir $(ROOT)/gen/cross
	ln -s $(UNICODE_DIR) cross/unicode