OPENCM3_DIR 	?= libopencm3
CMSIS_DIR 	?= cmsis
MSPDEBUG_DIR 	?= mspdebug
LIBSODIUM_DIR	?= libsodium
TINYAES_DIR	?= tinyaes
MUSL_DIR	?= musl

C_SOURCES		:= src/main.c src/mspdebug_wrapper.c src/spi_flash.c src/freq_meas.c src/dsss_demod.c
C_SOURCES		+= $(MSPDEBUG_DIR)/drivers/jtaglib.c

CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_rfft_fast_init_f32.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_rfft_fast_f32.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_cfft_init_f32.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_cfft_radix8_f32.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/CommonTables/arm_const_structs.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/CommonTables/arm_common_tables.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c
CMSIS_SOURCES		+= $(CMSIS_DIR)/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal2.c

MUSL_SOURCES		+= $(MUSL_DIR)/src/math/tanhf.c $(MUSL_DIR)/src/math/atanhf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/expm1f.c $(MUSL_DIR)/src/math/log1pf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/expf.c $(MUSL_DIR)/src/math/exp2f_data.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/powf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/__math_oflowf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/__math_uflowf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/__math_xflowf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/__math_invalidf.c
MUSL_SOURCES		+= $(MUSL_DIR)/src/math/powf_data.c

C_SOURCES += $(CMSIS_SOURCES) $(MUSL_SOURCES)

CXX_SOURCES		+= src/ldpc_wrapper.cpp

BUILDDIR 	?= build
BINARY 		:= safetyreset.elf
LDSCRIPT 	:= stm32f407.ld
OPENCM3_LIB	:= opencm3_stm32f4

PREFIX		?= arm-none-eabi-


FMEAS_ADC_SAMPLING_RATE ?= 1000
FMEAS_ADC_MAX			?= 4096
FMEAS_FFT_LEN			?= 256
FMEAS_FFT_WINDOW 		?= gaussian
FMEAS_FFT_WINDOW_SIGMA 	?= 16.0
# TODO: validate
FMEAS_SAMPLING_RATE		?= 10.0

DSSS_GOLD_CODE_NBITS 	?= 5
DSSS_DECIMATION			?= 10
# TODO maybe auto adjust this based on detection rate?
DSSS_THESHOLD_FACTOR	?= 6.0f
DSSS_WAVELET_WIDTH		?= 7.3
DSSS_WAVELET_LUT_SIZE	?= 69
DSSS_FILTER_FC			?= 3e-3
DSSS_FILTER_ORDER		?= 12

PAYLOAD_DATA_BIT		?= 64
TRANSMISSION_SYMBOLS	?= 32

CC			:= $(PREFIX)gcc
CXX			:= $(PREFIX)g++
LD			:= $(PREFIX)gcc
AR			:= $(PREFIX)ar
AS			:= $(PREFIX)as
OBJCOPY		:= $(PREFIX)objcopy
OBJDUMP		:= $(PREFIX)objdump
GDB			:= $(PREFIX)gdb

HOST_CC				?= $(HOST_PREFIX)gcc
HOST_CXX			?= $(HOST_PREFIX)g++
HOST_LD				?= $(HOST_PREFIX)gcc
HOST_AR				?= $(HOST_PREFIX)ar
HOST_AS				?= $(HOST_PREFIX)as
HOST_OBJCOPY		?= $(HOST_PREFIX)objcopy
HOST_OBJDUMP		?= $(HOST_PREFIX)objdump

PYTHON3 ?= python3

OPENCM3_DIR_ABS 	:= $(abspath $(OPENCM3_DIR))
CMSIS_DIR_ABS 		:= $(abspath $(CMSIS_DIR))
MSPDEBUG_DIR_ABS 	:= $(abspath $(MSPDEBUG_DIR))
LIBSODIUM_DIR_ABS	:= $(abspath $(LIBSODIUM_DIR))
TINYAES_DIR_ABS		:= $(abspath $(TINYAES_DIR))
MUSL_DIR_ABS		:= $(abspath $(MUSL_DIR))

COMMON_CFLAGS		+= -I$(OPENCM3_DIR_ABS)/include -Imspdebug/util -Imspdebug/drivers -Ilevmarq
COMMON_CFLAGS		+= -I$(CMSIS_DIR_ABS)/CMSIS/DSP/Include -I$(CMSIS_DIR_ABS)/CMSIS/Core/Include 
CFLAGS				+= -I$(abspath musl_include_shims)
COMMON_CFLAGS		+= -I$(BUILDDIR) -Isrc

COMMON_CFLAGS	+= -Os -std=gnu11 -g -DSTM32F4
CFLAGS			+= -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16
#SIM_CFLAGS		+= -mthumb -mcpu=cortex-m4 -mfloat-abi=soft
# Note: libopencm3 requires some standard libc definitions from stdint.h and stdbool.h, so we don't pass -nostdinc here.
CFLAGS			+= -nostdlib -ffreestanding
CFLAGS			+= -fno-common -ffunction-sections -fdata-sections
COMMON_CFLAGS	+= -DDSSS_GOLD_CODE_NBITS=$(DSSS_GOLD_CODE_NBITS) -DFMEAS_FFT_LEN=$(FMEAS_FFT_LEN) -DFMEAS_ADC_MAX=$(FMEAS_ADC_MAX)
COMMON_CFLAGS	+= -DFMEAS_ADC_SAMPLING_RATE=$(FMEAS_ADC_SAMPLING_RATE)
COMMON_CFLAGS	+= -DFMEAS_FFT_WINDOW_SIGMA=$(FMEAS_FFT_WINDOW_SIGMA)
COMMON_CFLAGS	+= -DDSSS_DECIMATION=$(DSSS_DECIMATION)
COMMON_CFLAGS	+= -DDSSS_THESHOLD_FACTOR=$(DSSS_THESHOLD_FACTOR)
COMMON_CFLAGS	+= -DDSSS_WAVELET_WIDTH=$(DSSS_WAVELET_WIDTH)
COMMON_CFLAGS	+= -DDSSS_WAVELET_LUT_SIZE=$(DSSS_WAVELET_LUT_SIZE)
COMMON_CFLAGS	+= -DPAYLOAD_DATA_BIT=$(PAYLOAD_DATA_BIT)
COMMON_CFLAGS	+= -DTRANSMISSION_SYMBOLS=$(TRANSMISSION_SYMBOLS)

# for musl
CFLAGS			+= -Dhidden=

SIM_CFLAGS	+= -lm -DSIMULATION

INT_CFLAGS	+= -Wall -Wextra -Wpedantic -Wshadow -Wimplicit-function-declaration -Wundef
INT_CFLAGS	+= -Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes

CXXFLAGS	+= -Os -g
CXXFLAGS	+= -nostdlib -ffreestanding
CXXFLAGS	+= -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16
CXXFLAGS	+= -fno-common -ffunction-sections -fdata-sections
CXXFLAGS	+= -Wall -Wextra -Wshadow -Wundef -Wredundant-decls
CXXFLAGS	+= -I.

COMMON_LDFLAGS	+= -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 -g
LDFLAGS			+= --static -nostartfiles
LDFLAGS			+= -Wl,--cre
#LDFLAGS		+= -Wl,--gc-sections
LDFLAGS			+= -Wl,--start-group -lc -lgcc -lnosys -Wl,--end-group
LDFLAGS			+= -L$(OPENCM3_DIR_ABS)/lib -l$(OPENCM3_LIB) $(shell $(CC) -print-libgcc-file-name)

all: $(BUILDDIR)/$(BINARY)

src/dsss_demod.c: $(BUILDDIR)/generated/dsss_gold_code.h $(BUILDDIR)/generated/dsss_butter_filter.h

$(BUILDDIR)/generated/dsss_gold_code.h: $(BUILDDIR)/generated/gold_code_$(DSSS_GOLD_CODE_NBITS).h
	ln -srf $< $@

.PRECIOUS: $(BUILDDIR)/generated/gold_code_%.c
$(BUILDDIR)/generated/gold_code_%.c $(BUILDDIR)/generated/gold_code_%.h: | $(BUILDDIR)/generated
	$(PYTHON3) tools/gold_code_header_gen.py -v dsss_gold_code_table -$(patsubst .%,%,$(suffix $@)) $* > $@

.PRECIOUS: $(BUILDDIR)/generated/fmeas_fft_window.c
$(BUILDDIR)/generated/fmeas_fft_window.c: | $(BUILDDIR)/generated
	$(PYTHON3) tools/fft_window_header_gen.py -v fmeas_fft_window_table $(FMEAS_FFT_WINDOW) $(FMEAS_FFT_LEN) $(FMEAS_FFT_WINDOW_SIGMA) > $@

.PRECIOUS: $(BUILDDIR)/generated/dsss_cwt_wavelet.c
$(BUILDDIR)/generated/dsss_cwt_wavelet.c: | $(BUILDDIR)/generated
	$(PYTHON3) tools/cwt_wavelet_header_gen.py -v dsss_cwt_wavelet_table $(DSSS_WAVELET_LUT_SIZE) $(DSSS_WAVELET_WIDTH) > $@

.PRECIOUS: $(BUILDDIR)/generated/dsss_butter_filter.h
$(BUILDDIR)/generated/dsss_butter_filter.h: | $(BUILDDIR)/generated
	$(PYTHON3) tools/butter_filter_gen.py -m dsss_filter $(DSSS_FILTER_FC) $(FMEAS_SAMPLING_RATE) $(DSSS_FILTER_ORDER) > $@

$(BUILDDIR)/generated: ; mkdir -p $@

OBJS := $(addprefix $(BUILDDIR)/,$(C_SOURCES:.c=.o) $(CXX_SOURCES:.cpp=.o))

ALL_OBJS := $(OBJS)
ALL_OBJS += $(OPENCM3_DIR)/lib/lib$(OPENCM3_LIB).a
ALL_OBJS += $(BUILDDIR)/libsodium/src/libsodium/.libs/libsodium.a
ALL_OBJS += $(BUILDDIR)/tinyaes/aes.o
ALL_OBJS += $(BUILDDIR)/levmarq/levmarq.o
ALL_OBJS += $(BUILDDIR)/generated/gold_code_$(DSSS_GOLD_CODE_NBITS).o
ALL_OBJS += $(BUILDDIR)/generated/fmeas_fft_window.o
ALL_OBJS += $(BUILDDIR)/generated/dsss_cwt_wavelet.o 

$(BUILDDIR)/$(BINARY): $(ALL_OBJS)
	$(LD) -T$(LDSCRIPT) $(COMMON_LDFLAGS) $(LDFLAGS) -o $@ -Wl,-Map=$(BUILDDIR)/src/$*.map $^

tools: $(BUILDDIR)/tools/freq_meas_test
$(BUILDDIR)/tools/freq_meas_test: tools/freq_meas_test.c src/freq_meas.c levmarq/levmarq.c $(BUILDDIR)/generated/fmeas_fft_window.c $(CMSIS_SOURCES)
	mkdir -p $(@D)
	$(HOST_CC) $(COMMON_CFLAGS) $(SIM_CFLAGS) -o $@ $^

tools: $(BUILDDIR)/tools/dsss_demod_test
$(BUILDDIR)/tools/dsss_demod_test: tools/dsss_demod_test.c src/dsss_demod.c $(BUILDDIR)/generated/dsss_cwt_wavelet.c $(BUILDDIR)/generated/gold_code_$(DSSS_GOLD_CODE_NBITS).c
	mkdir -p $(@D)
	$(HOST_CC) $(COMMON_CFLAGS) $(SIM_CFLAGS) -o $@ $^

$(BUILDDIR)/src/%.o: src/%.c
	mkdir -p $(@D)
	$(CC) $(COMMON_CFLAGS) $(CFLAGS) $(INT_CFLAGS) -o $@ -c $<

$(BUILDDIR)/src/%.o: src/%.cpp
	mkdir -p $(@D)
	$(CXX) $(CXXFLAGS) -o $@ -c $<

$(BUILDDIR)/generated/%.o: $(BUILDDIR)/generated/%.c
	mkdir -p $(@D)
	$(CC) $(COMMON_CFLAGS) $(CFLAGS) $(INT_CFLAGS) -o $@ -c $<

$(BUILDDIR)/%.o: %.c
	mkdir -p $(@D)
	$(CC) $(COMMON_CFLAGS) $(CFLAGS) $(EXT_CFLAGS) -o $@ -c $<

$(OPENCM3_DIR)/lib/lib$(OPENCM3_LIB).a:
	$(MAKE) -C $(OPENCM3_DIR) -j $(shell nproc)

$(BUILDDIR)/libsodium/src/libsodium/.libs/libsodium.a:
	mkdir -p $(BUILDDIR)/libsodium
	cd $(BUILDDIR)/libsodium && CFLAGS="$(COMMON_CFLAGS) $(CFLAGS) -DDEV_MODE=1" $(LIBSODIUM_DIR_ABS)/configure --host=arm-none-eabi && $(MAKE) -j $(shell nproc)

$(BUILDDIR)/tinyaes/aes.o:
	mkdir -p $(@D)
	make -C $(@D) -f $(TINYAES_DIR_ABS)/Makefile VPATH=$(TINYAES_DIR_ABS) CFLAGS="$(COMMON_CFLAGS) $(CFLAGS) -c" CC=$(CC) LD=$(LD) AR=$(AR) aes.o

$(BUILDDIR)/musl/lib/libc.a:
	mkdir -p $(BUILDDIR)/musl
	cd $(BUILDDIR)/musl && CFLAGS="$(SIM_CFLAGS) $(COMMON_CFLAGS)" CC=$(CC) LD=$(LD) AR=$(AR) $(MUSL_DIR_ABS)/configure && $(MAKE) TARGET=arm-linux-musleabihf GCC_CONFIG="-mcpu=cortex-m4 -mfloat-abi=soft" -j $(shell nproc)

build/ldpc_decoder_test.so: src/ldpc_decoder.c
	gcc -fPIC -shared -Wall -Wextra -Wpedantic -std=gnu11 -O0 -g -o $@ $^

clean:
	rm -rf $(BUILDDIR)/src
	rm -rf $(BUILDDIR)/generated
	rm -f $(BUILDDIR)/$(BINARY)
	rm -f $(BUILDDIR)/tools/freq_meas_test

mrproper: clean
	rm -rf build
	-$(MAKE) -C $(OPENCM3_DIR) clean

.PHONY: clean mrproper

-include $(OBJS:.o=.d)