.POSIX:
.SUFFIXES: .apk .unsigned .aligned

PROJECT = helloworld
ANDROIDSDK = /usr/lib/android-sdk
DX = $(ANDROIDSDK)/build-tools/debian/dx
MANIFEST = AndroidManifest.xml
PLATFORM = $(ANDROIDSDK)/platforms/android-23/android.jar
OBJECTS = \
	HelloWorld.class \
	Test.class
RESOURCES = \
	res/layout/activity_main.xml
R = helloworld/R.java

# Resources:
# https://www.hanshq.net/command-line-android.html

all: $(PROJECT).apk

$(PROJECT).apk: keystore.jks

.aligned.apk:
	apksigner sign \
		--ks keystore.jks \
		--ks-key-alias androidkey \
		--ks-pass pass:android \
		--key-pass pass:android \
		--out $@ $<

keystore.jks:
	keytool \
		-genkeypair \
		-keystore $@ \
		-alias androidkey \
		-validity 10000 \
		-keyalg RSA \
		-keysize 4096 \
		-storepass android \
		-keypass android

.unsigned.aligned:
	zipalign -f -p 4 $< $@

$(PROJECT).unsigned: dex/classes.dex $(MANIFEST)
	aapt package -f -F $@ -I $(PLATFORM) -M $(MANIFEST) -S res dex

dex/classes.dex: $(OBJECTS) $(MANIFEST)
	mkdir -p dex
	$(DX) --dex --output=$@ $(OBJECTS)

$(OBJECTS): $(OBJECTS:.class=.java) $(R)
	javac -bootclasspath $(PLATFORM) -source 1.7 $(OBJECTS:.class=.java)

$(R): $(MANIFEST) $(RESOURCES)
	aapt package -f -m -S res -M $(MANIFEST) -I $(PLATFORM) -J .

clean:
	rm -f $(R) $(OBJECTS) $(PROJECT).unsigned \
		$(PROJECT).aligned $(PROJECT).apk.idsig dex/classes.dex

distclean: clean
	rm -rf dex/ *.apk keystore.jks