#
# Copyright (C) 2019 Michael Zucchi
#
# This is the copyright for java.make
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

# General purpose modular java makefile that supports native library
# compilation directly.  Non-recrusve implementation.
#
# Uses metamake programming with some file conventions to implement
# auto-make-like features.

# Define modules
# --------------
# java_MODULES list of java modules to compile.  The sources must
# 		exist in src/<module>/classes.  Resource files are
# 		stored in src/<module>/classes.  Source-code
# 		generators must exist in src/<module>/gen.  Native
# 		libraries must exist in src/<module>/jni.

# Global variables

# JAVA_HOME		location of jdk.
# JAVAC			java compiler to use.  Default is 'javac' on the path.
# JAVACFLAGS		javac flags applied to all invocations.
# JAR 			jar command.
# JARFLAGS		jar flags
# JMOD			jmod command.
# JMODFLAGS		jmod flags.

# Module specific variables

# <module>_JDEPMOD	Lists modules which this one depends on.

# <module>_JAVACFLAGS	Extra module-specific flags for each command.
# <module>_JARFLAGS
# <module>_JMODFLAGS

# <module>_JAVA			Java sources.  If not set it is found from src/<module>/classes/(*.java)
# <module>_RESOURCES		.jar resources.  If not set it is found from src/<module>/classes/(not *.java)
# <module>_JAVA_GENERATED	Java generated sources.  These must be relative to the package name.

# Variables for use in fragments

# gen.make and jni.make can additionally make use of these variables

# <module>_gendir	Location for files used in Java generation process (per project).
# <module>_genjavadir	Location where _JAVA_GENERATED .java files will be created (per project).
# <module>_jnidir	Location for jni generated files (per target).
# <module>_objdir	Location for c objects (per target).
# <module>_incdir	Location for output includes, .jmod staging.
# <module>_libdir	Location for output libraries, .jmod staging.  May point to _bindir.
# <module>_bindir	Location for output commands, .jmod staging.

# Define libraries
# ----------------

# Each module can define one or more native libraries.

# These are compiled after the java sources have been compiled as that
# process also generates any native binding headers.

# <module>_JNI_LIBRARIES	list of libraries to build.
# library names match System.loadLibrary().

# Global variables

# <target>_LDFLAGS
# <target>_LDLIBS
# <target>_CPPFLAGS
# <target>_CFLAGS
# SO		shared library suffix
# LIB		shared library prefix

# Utility functions
#
# $(call library-path,<module>,<libname>) will resolve to the library file name.

# Per library variables.

# <library>_SOURCES	.c, .cc, .C - source files for library.  Paths are relative to src/<module>/jni.
# <library>_HEADERS	header files for jmod
# <library>_COMMANDS	commands/bin/scripts for jmod

# <library>_LDFLAGS	link flags
# <library>_LIBADD	extra objects to add to link line
# <library>_LDLIBS	link libraries
# <library>_CPPFLAGS	c pre-processor flags.  "-Isrc/<module>/jni -Ibin/include/<module>" is implicit.
# <library>_CCFLAGS	c compiler flags

# <library>_DEPENDENCIES 	A list of other objects on which this library depends before linking.

# <library>_DEFS	A list of .def files for nativez-gen.
# <library>_DEFSFLAGS	Flags for nativez-gen invocation.

# .c files have dependencies automatically generated

# Targets
# -------

# make gen		only generate java sources
# make clean		rm -rf bin
# make dist		create dist tar in bin/
# make | make jar	make all jars and jmods
# make bin		make everything but jars and mods

# Outputs
# -------

# All intermediate and output files are written to bin/

# This layout is enforced by javac
#  bin/include/<module>/        .h files from javac -h
#  bin/modules/<module>/        .class files from javac

# This layout is convenient for netbeans
#  bin/gen/<module>/gen/	.c, exe files for generator	free use
#  bin/gen/<module>/classes/	.java files from generator	<module>_JAVA_GENERATED

# Working files
#  bin/status/			marker files for makefile

#  bin/<module>/<target>/lib	.so librareies for jmod		<module>_LIBRARIES = libname
#  bin/<module>/<target>/obj	.o, .d files for library	<libname>_SOURCES
#  bin/<module>/<target>/include .h files for jmod  		<libname>_HEADERS
#  bin/<module>/<target>/<module>.jmod	.jmod module

# Output files
#  bin/<target>/lib/		modular jar files and shared libraries for GNU/linux dev
#  bin/<target>/include/	header files for exported shared libraries
#  bin/<target>/bin/		shared libraries for microsoft dev
#  bin/<target>/jmods/		jmod files for 'jlink' use.

# ######################################################################

E:=
S:=$(E) $(E)

# All modules with native code
java_JMODS=$(foreach module,$(java_MODULES),$(if $(wildcard src/$(module)/jni/jni.make),$(module)))
# Only modules with no native code
java_JARS=$(foreach module,$(java_MODULES),$(if $(wildcard src/$(module)/jni/jni.make),,$(module)))
# Modules with generated java source
java_JGEN=$(foreach module,$(java_MODULES),$(if $(wildcard src/$(module)/gen/gen.make),$(module)))

# Define some useful variables before including fragments
define java_variables=
$(1)_gendir:=bin/gen/$(1)/gen
$(1)_genjavadir:=bin/gen/$(1)/classes
$(1)_jnidir:=bin/$(1)/$(TARGET)/jni
$(1)_objdir:=bin/$(1)/$(TARGET)/obj
$(1)_incdir:=bin/$(1)/$(TARGET)/include
$(1)_libdir:=$$(if $$(filter windows-%,$(TARGET)),bin/$(1)/$(TARGET)/bin,bin/$(1)/$(TARGET)/lib)
$(1)_bindir:=bin/$(1)/$(TARGET)/bin
ifndef $(1)_JAVA
$(1)_JAVA := $$(shell find src/$(1)/classes -type f -name '*.java')
endif
ifndef $(1)_RESOURCES
$(1)_RESOURCES := $$(shell find src/$(1)/classes -type f \! -name '*.java')
endif
endef

java_libdir:=$(if $(filter windows-%,$(TARGET)),bin/$(TARGET)/bin,bin/$(TARGET)/lib)
java_bindir:=bin/$(TARGET)/bin
java_jardir:=bin/$(TARGET)/lib
java_incdir:=bin/$(TARGET)/include
java_jmoddir:=bin/$(TARGET)/jmods

$(foreach module,$(java_MODULES),$(eval $(call java_variables,$(module))))

# ######################################################################

all: jar
bin:
gen:

.PHONY: all clean jar bin gen
clean:
	rm -rf bin

include $(patsubst %,src/%/gen/gen.make,$(java_JGEN))
include $(patsubst %,src/%/jni/jni.make,$(java_JMODS))

# ######################################################################
# Java
# ######################################################################

define java_targets=
# Rules for module $(1)
$(1)_JAVA_generated = $$(addprefix $$($(1)_genjavadir)/,$$($(1)_JAVA_GENERATED))

bin/status/$(1).data: $$($(1)_RESOURCES)
bin/status/$(1).classes: $(patsubst %,bin/status/%.classes,$($(1)_JDEPMOD)) $$($(1)_JAVA) $$($(1)_JAVA_generated)
jar $(1): $(java_jardir)/$(1).jar $(java_jmoddir)/$(1).jmod
bin: bin/status/$(1).classes bin/status/$(1).data
sources: $(java_jardir)/$(1)-sources.zip
gen: $$($(1)_JAVA_generated)

# Create modular jar
$(java_jardir)/$(1).jar: bin/status/$(1).classes bin/status/$(1).data
	@install -d $$(@D)
	$(JAR) cf $$@ \
	  $(JARFLAGS) $$($(1)_JARFLAGS) \
	  -C bin/modules/$(1) .

# Create a jmod
$(java_jmoddir)/$(1).jmod: bin/status/$(1).classes bin/status/$(1).data
	rm -f $$@
	@install -d $$(@D)
	$$(JMOD) create \
	  $$(JMODFLAGS) $$($(1)_JMODFLAGS) \
	  --target-platform $(TARGET) \
	  --class-path bin/modules/$(1) \
	  $$(if $$(wildcard bin/$(1)/$(TARGET)/include),--header-files bin/$(1)/$(TARGET)/include) \
	  $$(if $$(wildcard src/$(1)/legal),--legal-notices src/$(1)/legal) \
	  $$(if $$(wildcard bin/$(1)/$(TARGET)/bin),--cmds bin/$(1)/$(TARGET)/bin) \
	  $$(if $$(wildcard bin/$(1)/$(TARGET)/lib),--libs bin/$(1)/$(TARGET)/lib) \
	  $$@

# Create an IDE source zip, paths have to match --module-source-path
$(java_jardir)/$(1)-sources.zip: bin/status/$(1).classes
	@install -d $$(@D)
	jar -c -f $$@ -M \
		$$(patsubst src/$(1)/classes/%,-C src/$(1)/classes %,$$(filter src/$(1)/classes/%,$$($(1)_JAVA))) \
		$$(patsubst bin/gen/$(1)/classes/%,-C bin/gen/$(1)/classes %,$$(filter bin/gen/$(1)/classes/%,$$($(1)_JAVA)))

endef

#$(foreach module,$(java_MODULES),$(info $(call java_targets,$(module))))
$(foreach module,$(java_MODULES),$(eval $(call java_targets,$(module))))

# ######################################################################
# Global pattern rules

# Stage resources
bin/status/%.data:
	@install -d $(@D)
	for data in $(patsubst src/$*/classes/%,"%",$($*_RESOURCES)) ; do \
		install -vDC "src/$*/classes/$$data" "bin/modules/$*/$$data" || exit 1 ; \
	done
	touch $@

# Compile one module.  This only updates (javac -h) headers if they changed.
bin/status/%.classes:
	@install -d $(@D)
	$(JAVAC) \
		--module-source-path "src/*/classes:bin/gen/*/classes" \
		$(if $(JAVAMODPATH),--module-path $(subst $(S),:,$(JAVAMODPATH))) \
		$(JAVACFLAGS) $($*_JAVACFLAGS) \
		-h bin/inc \
		-d bin/modules \
		-m $* \
		$($*_JAVA) $($*_JAVA_generated)
	if [ -d bin/inc/$* ] ; then \
		install -DC -t bin/include/$* bin/inc/$*/*.h ; \
	fi
	touch $@

# ######################################################################
# C stuff
# ######################################################################

SUFFIXES=.c .C .cc
SO=$($(TARGET)_SO)
LIB=$($(TARGET)_LIB)

# functions to find cross-module stuff $(call library-path,modname,libname)
library-path=$($(1)_libdir)/$(LIB)$(2)$(SO)
library-dir=$($(1)_libdir)/

define jni_library=
# Rule for library $(2) in module $(1)
$(2)_OBJS = $(foreach sx,$(SUFFIXES),$(patsubst %$(sx), $($(1)_objdir)/%.o, $(filter %$(sx),$($(2)_SOURCES))))
$(2)_SRCS = $(addprefix src/$(1)/jni/,$($(2)_SOURCES))
$(2)_SO = $($(1)_libdir)/$(LIB)$(2)$(SO)

$($(1)_libdir)/$(LIB)$(2)$(SO): $$($(2)_OBJS) $($(2)_LIBADD) $($(2)_DEPENDENCIES)
	@install -d $$(@D)
	$($(TARGET)_CC) -o $$@ -shared \
		$($(TARGET)_LDFLAGS) $($(2)_LDFLAGS) $$($(2)_OBJS) $($(2)_LIBADD) $($(TARGET)_LDLIBS) $($(2)_LDLIBS)

$(java_libdir)/%: $($(1)_libdir)/%
	install -DC $$< $$@
$(java_bindir)/%: $($(1)_bindir)/%
	install -DC $$< $$@
$(java_incdir)/%: $($(1)_incdir)/%
	install -DC $$< $$@

$($(1)_objdir)/%.o: src/$(1)/jni/%.c
	@install -d $$(@D)
	$($(TARGET)_CC) -Isrc/$(1)/jni -Ibin/include/$(1) -I$($(1)_jnidir) \
		$($(TARGET)_CPPFLAGS) $($(2)_CPPFLAGS) \
		$($(TARGET)_CFLAGS) $($(2)_CFLAGS) -c -o $$@ $$<

$($(1)_incdir)/%.h: src/$(1)/jni/%.h
	install -DC $$< $$@

# auto-dependencies for c files
$($(1)_objdir)/%.d: src/$(1)/jni/%.c bin/status/$(1).classes
	@install -d $$(@D)
	@rm -f $$@
	@$($(TARGET)_CC) -MM -MT "bin/$(1)/$(TARGET)/obj/$$*.o" -Isrc/$(1)/jni -Ibin/include/$(1) \
		$($(TARGET)_CPPFLAGS) $($(2)_CPPFLAGS) $$< -o $$@.d 2>/dev/null
	@sed 's,\($$*\.o\) *:,\1 $$@ : ,g' $$@.d > $$@ ; rm $$@.d

# .def files for nativez mapping
$($(1)_jnidir)/%.h: src/$(1)/jni/%.def
	@install -d $$(@D)
	$(NATIVEZ_HOME)/bin/nativez-gen -J $($(2)_DEFSFLAGS) $$< > $$@ || ( rm $$@ ; exit 1)

bin jni $(1) $(java_jmoddir)/$(1).jmod: \
	$($(1)_libdir)/$(LIB)$(2)$(SO) \
	$(java_libdir)/$(LIB)$(2)$(SO) \
	$(addprefix $($(1)_incdir)/,$($(2)_HEADERS)) \
	$(addprefix $(java_incdir)/,$($(2)_HEADERS)) \
	$(addprefix $($(1)_bindir)/,$($(2)_COMMANDS)) \
	$(addprefix $(java_bindir)/,$($(2)_COMMANDS)) \
	$(addprefix $($(1)_libdir)/,$($(2)_LIBRARIES))

$(if $(filter clean dist gen,$(MAKECMDGOALS)),,-include $$($(2)_OBJS:.o=.d))
endef

#$(foreach module,$(java_JMODS),$(foreach library,$($(module)_JNI_LIBRARIES),$(info $(call jni_library,$(module),$(library)))))
$(foreach module,$(java_JMODS),$(foreach library,$($(module)_JNI_LIBRARIES),$(eval $(call jni_library,$(module),$(library)))))

#$(foreach module,$(java_JMODS),$(foreach library,$($(module)_JNI_LIBRARIES),$(foreach def,$($(library)_DEFS),$(info $($(module)_objdir)/$(def:.def=.o): $($(module)_jnidir)/$(def:.def=.h)))))
$(foreach module,$(java_JMODS),$(foreach library,$($(module)_JNI_LIBRARIES),$(foreach def,$($(library)_DEFS),$(eval $($(module)_objdir)/$(def:.def=.o): $($(module)_jnidir)/$(def:.def=.h)))))

# ######################################################################

dist:
	@install -d bin
	tar cfz bin/$(dist_NAME)-$(dist_VERSION).tar.gz	\
	 --transform=s,^,$(dist_NAME)-$(dist_VERSION)/,	\
	 config.make java.make Makefile	src		\
	 $(dist_EXTRA)