.ONESHELL:

SHELL=/bin/makefile-bash-wrapper.sh

# the include of the Makefile.app-config defines the Makefile
# variables $(BUILDTOOLS), $(ANDROID_JAR) and $(PACKAGE)
# which depend on the configuration and are necessary to have the Makefile work
# the rule whose target is Makefile.app-config will trigger a reload of this include as ncessary
# (as explained https://make.mad-scientist.net/papers/advanced-auto-dependency-generation/#include)
include Makefile.app-config

# litanay of variabes used 
NDK:=./android-sdk/ndk/21.1.6352462
NDK_TOOLCHAIN:=$(NDK)/toolchains/llvm/prebuilt/linux-x86_64
NDK_TOOLCHAIN_INCLUDE:=$(NDK_TOOLCHAIN)/sysroot/usr/include
ANDROIDVERSION:=29
CC_ARM64:=$(NDK_TOOLCHAIN)/bin/aarch64-linux-android29-clang
CFLAGS?=-ffunction-sections -Os -fdata-sections -Wall -fvisibility=hidden
CFLAGS += -fvisibility=hidden
# APP_PACKAGE is set to (-D) i.e preprocessor value and used to set string when logging
CFLAGS+=-Os -DANDROID -DAPP_PACKAGE=\"$(APP_PACKAGE)\"
# the -D will likely set a Variable to be used in the Preprocessor
CFLAGS +=-DANDROID_FULLSCREEN
CFLAGS+= -I./src/nativecode/rawdraw -I./src/nativecode -I$(NDK)/sysroot/usr/include 
CFLAGS+= -I$(NDK)/sysroot/usr/include/android -I$(NDK_TOOLCHAIN_INCLUDE) -I$(NDK_TOOLCHAIN_INCLUDE)/android 
CFLAGS+= -fPIC -DANDROIDVERSION=$(ANDROIDVERSION)
CFLAGS_ARM64:=-m64
LDFLAGS?=-Wl,--gc-sections -Wl,-Map=output.map -s
LDFLAGS += -s
# LDFLAGS += -static-libstdc++
LDFLAGS += -lm -lGLESv3 -lEGL -landroid -llog -lOpenSLES
LDFLAGS += -shared -uANativeActivity_onCreate
# locatoins of "mostly c" source files 
SRC?=./src/nativecode/test.c
RAWDRAWANDROIDSRCS=./src/nativecode/android_native_app_glue.c
ANDROIDSRCS:= $(SRC) $(RAWDRAWANDROIDSRCS)


# symlink
./app.apk:  ./result/app.apk
	ln -sfrv ./result/app.apk ./app.apk

# zipalign and sign again (second signing)
./result/app.apk : ./result/unsigned.apk app-config.sh ./keystore
	$(BUILDTOOLS)/zipalign -v -f 4 $< $@
	$(BUILDTOOLS)/apksigner sign --ks keystore --key-pass pass:armena --ks-pass pass:armena  $@

## sign the apk file (first sign)
#./result/signed.apk : ./result/unsigned.apk ./keystore 
#	jarsigner -verbose -keystore ./keystore -storepass armena -keypass armena -signedjar $@ $< helljniKey

# make a "keystore" for the cryptographic signing stuff
./keystore : 
	keytool -genkeypair -validity 2000 -dname "CN=$(APP_PACKAGE),O=Android,C=IT" -keystore $@ \
	-storepass armena -keypass armena -alias helljniKey -keyalg RSA -v

# aapt "package" together the dalvik/hex stuff (and "assets" and "res")
./result/unsigned.apk : ./assets  ./AndroidManifest.xml ./result/bin/lib/arm64-v8a/libnativecode.so $(shell find ./res -type f) 
	rm -rvf "$@"
	$(BUILDTOOLS)/aapt package \
	  -v -u -f -M ./AndroidManifest.xml -S ./res \
	  -I $(ANDROID_JAR) -A ./assets -F $@ ./result/bin

supi: 
	echo $(shell find ./res -type f)

alex: ./result/bin/classes.dex 
	echo $< > $@

## convert "java class"es files (i.e bytecode) to dalvic/d8 android thing
#./result/bin/classes.dex : ./obj/$(PACKAGE)/AppActivity.class 
#	mkdir -p ./result/bin
#	$(BUILDTOOLS)/d8 ./obj/$(PACKAGE)/*.class \
#	  --lib $(ANDROID_JAR) --output ./result/bin; RESULT=$$?; echo result was $$RESULT; (exit $$RESULT)


./result/bin/lib/arm64-v8a/libnativecode.so: $(ANDROIDSRCS) ./android-sdk/installed
	mkdir -p "$$(dirname "$@")"
	$(CC_ARM64) $(CFLAGS) $(CFLAGS_ARM64) -o $@ $(ANDROIDSRCS) -L$(NDK_TOOLCHAIN)/sysroot/usr/lib/aarch64-linux-android/$(ANDROIDVERSION) $(LDFLAGS)



## compile (javac) the class from 
#./obj/$(PACKAGE)/AppActivity.class : ./src/$(PACKAGE)/AppActivity.java  ./src/$(PACKAGE)/R.java 
#	mkdir -p ./obj/$(PACKAGE)
#	javac -d ./obj -classpath $(ANDROID_JAR) -sourcepath ./src $<
#
#
## make the resources "R.java" thing
#./src/$(PACKAGE)/R.java : $(shell find ./res -type f) app-config.sh ./AndroidManifest.xml ./android-sdk/installed | ./src/$(PACKAGE)
#	$(BUILDTOOLS)/aapt package \
#	  -v -f -m  -S ./res -J ./src -M ./AndroidManifest.xml \
#	  -I $(ANDROID_JAR)

## generate the AppActivity.java (template 
## the "|" denotes an "order-only" prerequiste (as in https://stackoverflow.com/a/58040049/1711186)
#./src/$(PACKAGE)/AppActivity.java: app-config.sh | ./src/$(PACKAGE)
#	./.Makefile.scripts/make--AppActivity.java.sh > $@

./src/$(PACKAGE):
	mkdir -p $@

# install the necessary android sdks
./android-sdk/installed: app-config.sh ./.Makefile.scripts/make--android-sdk.sh
	./.Makefile.scripts/make--android-sdk.sh

# generate the AndroidManifest.xml
./AndroidManifest.xml: app-config.sh ./.Makefile.scripts/make--AndroidManifest.xml
	./.Makefile.scripts/make--AndroidManifest.xml

Makefile.app-config: app-config.sh Makefile
	source app-config.sh; \
	tee $@ << MAKEFILE_APP_CONFIG
	ANDROIDVERSION:=$$APP_VERSION_SDK_TARGET;
	BUILDTOOLS:=$${ANDROID_SDK_ROOT}/build-tools/29.0.3/
	ANDROID_JAR:=$${ANDROID_SDK_ROOT}/platforms/android-29/android.jar
	PACKAGE:=$$(echo "$$APP_PACKAGE" | tr '.' '/')
	APP_PACKAGE=$${APP_PACKAGE}
	MAKEFILE_APP_CONFIG

# use whiptail textgui to make configuration (android API level, app-name, app-label etc...)
app-config.sh: 
	./.Makefile.scripts/make--app-config.sh

# rule to effectuate a cleanup
clean:
	rm -rf obj/* result/*

# this rule's purpose is to run "by force" no matter what, doing nothing
# as listed prerequisite to another rule it causes that rule to be made/run 
# unconditionally every time  
FORCE:
	@true