##
# LIBGTEST is the google test library
# GTEST_MAIN is the file that contains the google test
##
LIBGTEST = test/libgtest.a
GTEST_MAIN = $(GTEST)/src/gtest_main.cc
CFLAGS_GTEST += -I $(GTEST)/include -I $(GTEST)

##
# Target to verify header files are coherent
##
HEADER_TESTS := $(addsuffix -test,$(shell find src/stan -name '*.hpp' -type f)) 
ifeq ($(OS),win) 
  DEV_NULL = nul
else
  DEV_NULL = /dev/null
endif

test/dummy.cpp:
	@mkdir -p test
	@touch $@
	@echo "int main() {return 0;}" >> $@

%.hpp-test : %.hpp test/dummy.cpp
	$(COMPILE.c) -O0 -include $< -o $(DEV_NULL) test/dummy.cpp

##
# Target to verify compiled models are valid
##
.PHONY: %.cpp-test
%.cpp-test : %.cpp
	$(COMPILE.c) -fsyntax-only -O$O $< 

##
# Target to build all tests
##
.PHONY: test-all
test-all: test-unit test-headers test-distributions test-models


##
# Build the google test library.
## 
$(LIBGTEST): $(LIBGTEST)(test/gtest.o)

test/gtest.o: $(GTEST)/src/gtest-all.cc
	@mkdir -p test
	$(COMPILE.c) -O$O $(CFLAGS_GTEST) $< $(OUTPUT_OPTION)

test/%.o : src/test/%_test.cpp $(LIBGTEST)
	@mkdir -p $(dir $@)
	$(COMPILE.c) -O$O $(CFLAGS_GTEST) $< $(OUTPUT_OPTION)

##
# Rule for generating dependencies.
##
test/%.d : src/test/%_test.cpp
	@if test -d $(dir $@); \
	then \
	(set -e; \
	rm -f $@; \
	$(CC) $(CFLAGS) -O$O $(CFLAGS_GTEST) $(TARGET_ARCH) -MM $< > $@.$$$$; \
	sed -e 's,\($(notdir $*)\)\(_test\)\.o[ :]*,$(dir $@)\1.o $@ : ,g' < $@.$$$$ > $@; \
	rm -f $@.$$$$ ); \
	fi

ifneq (,$(filter test-unit,$(MAKECMDGOALS)))
  -include $(addsuffix .d, $(UNIT_TESTS)) 
endif
ifneq (,$(filter test-all,$(MAKECMDGOALS)))
  -include $(addsuffix .d, $(UNIT_TESTS)) 
endif

##
# run target which will allow for parallel execution of
# tests.
## 
.PHONY: runtest/%
.PRECIOUS: test/%
.SECONDARY:
runtest/% : %
	@echo '------------------------------------------------------------'
	$< --gtest_output="xml:$*.xml";

##
# target path_separator for use in some tests that need to 
# call executables.
##
.PHONY: path_separator
path_separator :
	@echo $(PATH_SEPARATOR)

##
# PERCENT used for secondary expansion
# $$(PERCENT) turns into %.
##
PERCENT = %

##
# TEST_TARGETS is the set of all src/test subdirectories excluding src/test.
##
TEST_TARGETS := $(shell find src/test ! -path src/test -type d)

##
# ALL_TESTS is the set of all test files
#   This needs to be an '=' assignment and not a ':='.
##
ALL_TESTS = $(shell find src/test -type f -name '*_test.cpp')

ALL_TEST_EXECUTABLES = $(patsubst src/%_test.cpp,%$(EXE),$(ALL_TESTS))

GRAMMAR_TESTS = $(foreach dir,\
                          $(patsubst src/%,%,$(shell find src/test -type d -name 'gm')),\
                          $(filter $(dir)/%,$(ALL_TEST_EXECUTABLES)))

##
# Generate autodependencies for test files.
# Adapted from the gnu make manual.
# http://www.gnu.org/software/make/manual/html_node/Automatic-Prerequisites.html#Automatic-Prerequisites
##
$(GRAMMAR_TESTS) : test/%$(EXE) : test/%.o bin/libstan.a bin/libstanc.a
	@mkdir -p $(dir $@)
	$(LINK.c) -O$O $(GTEST_MAIN) $< $(CFLAGS_GTEST) $(OUTPUT_OPTION) $(LIBGTEST) $(LDLIBS) $(LDLIBS_STANC)
ifeq ($(strip $(findstring test-,$(MAKECMDGOALS))\
              $(findstring runtest/,$(MAKECMDGOALS))\
              $(findstring src/test/,$(MAKECMDGOALS))),)
	$@ --gtest_output="xml:$(basename $@).xml"
endif

.PRECIOUS: test/%.o
test/%$(EXE) : test/%.o bin/libstan.a
	@mkdir -p $(dir $@)
	$(LINK.c) -O$O $(GTEST_MAIN) $< $(CFLAGS_GTEST) $(OUTPUT_OPTION) $(LIBGTEST) $(LDLIBS)
ifeq ($(strip $(findstring test-,$(MAKECMDGOALS))\
              $(findstring runtest/,$(MAKECMDGOALS))\
              $(findstring src/test/,$(MAKECMDGOALS))),)
	$@ --gtest_output="xml:$(basename $@).xml"
endif


####
## These make rules apply if SECONDEXPANSION is available
## in make.
#### 
ifneq ($(filter second-expansion,$(.FEATURES)),)
##
# Defining the test target implicit static rule.
#
# Each src/test/* depends on each executable that's generated
# by the test file.
##
.SECONDEXPANSION:
.PHONY: $(TEST_TARGETS)
$(TEST_TARGETS): src/test/%: $$(addprefix runtest/,$$(filter $$(patsubst src/$$(PERCENT),$$(PERCENT),$$@)/$$(PERCENT),$$(ALL_TEST_EXECUTABLES)))
	@echo ''
	$(if $(GENERATE_TESTS),\
             $(MAKE) $@ $(if $(J),-j$(J)), \
             @echo 'Ran '$(words $(filter runtest/%,$^))' tests for '$@)
else
####
## Warning for developers that don't have a 
## current enough version of make (3.81 or higher).
#### 
.PHONY: $(TEST_TARGETS)
$(TEST_TARGETS):
	@echo ''
	@echo '------------------------------------------------------------'
	@echo 'The current version of make does not satisfy the developer  '
	@echo 'requirements. Please install make 3.81 or higher.           '
	@echo '------------------------------------------------------------'
endif

##
# TEST_MODELS is the set of all the test models.
# Those in the 'compiled' subdirectory are supposed to be compiled.
# Those in the 'no_main' subdirectory are supposed to be compiled without a main function.
##
TEST_MODELS := $(shell find src/test/test-models -type f -name '*.stan')

##
# Compile these with a main.
## 
$(patsubst %.stan,%.cpp,$(filter src/test/test-models/compiled/%,$(TEST_MODELS))) : %.cpp : %.stan bin/stanc$(EXE)
	bin$(PATH_SEPARATOR)stanc$(EXE) --o=$@ $<
##
# Compile these with no main.
##
$(patsubst %.stan,%.cpp,$(filter src/test/test-models/no-main/%,$(TEST_MODELS))) : %.cpp : %.stan bin/stanc$(EXE)
	bin$(PATH_SEPARATOR)stanc$(EXE) --o=$@ --no_main $<


##
# Tests that also depend on generated models.
##
test/unit/io/mcmc_writer.o: src/test/test-models/no-main/io_example.cpp
test/unit/gm/command_init.o: src/test/test-models/no-main/gm/test_lp.cpp
test/unit/gm/command_write_iteration.o: src/test/test-models/no-main/gm/test_lp.cpp
test/unit/gm/generator.o: src/test/test-models/no-main/gm/test_lp.cpp

test/unit/model/util.o: src/test/test-models/no-main/model/valid.cpp src/test/test-models/no-main/model/domain_fail.cpp

test/unit/mcmc/hmc/hamiltonians/base_hamiltonian.o: src/test/test-models/no-main/mcmc/hmc/hamiltonians/funnel.cpp
test/unit/mcmc/hmc/hamiltonians/unit_e_metric.o: src/test/test-models/no-main/mcmc/hmc/hamiltonians/funnel.cpp
test/unit/mcmc/hmc/hamiltonians/diag_e_metric.o: src/test/test-models/no-main/mcmc/hmc/hamiltonians/funnel.cpp
test/unit/mcmc/hmc/hamiltonians/dense_e_metric.o: src/test/test-models/no-main/mcmc/hmc/hamiltonians/funnel.cpp
test/unit/mcmc/hmc/integrators/expl_leapfrog.o: src/test/test-models/no-main/mcmc/hmc/integrators/command.cpp src/test/test-models/no-main/mcmc/hmc/integrators/gauss.cpp

##
# all files that should be compiled as tests
##
FILES := $(shell find src/test/test-models/compiled -type f -name '*.stan')

test/integration/compile_models.o : $(patsubst %.stan,%$(EXE),$(FILES)) $(patsubst %.stan,%.cpp-test,$(wildcard src/test/test-models/syntax-only/*stan))

test/CmdStan/command.o: \
   $(addprefix src/test/test-models/compiled/CmdStan/,\
               $(addsuffix $(EXE), printer domain_fail value_fail proper))
test/CmdStan/gm/argument_configuration.o: src/test/test-models/compiled/CmdStan/test_model$(EXE)
test/CmdStan/fixed_param_sampler.o: src/test/test-models/compiled/CmdStan/empty$(EXE) src/test/test-models/compiled/CmdStan/proper$(EXE)
test/CmdStan/optimization_output.o: src/test/test-models/compiled/CmdStan/optimization_output$(EXE)

##
# CmdStan specific targets. Should be removed in the future.
##
$(patsubst src/%_test.cpp,%.o,$(filter src/test/CmdStan/%,$(ALL_TESTS))): test/%.o : src/test/%_test.cpp $(LIBGTEST) bin/print$(EXE)
	@mkdir -p $(dir $@)
	$(COMPILE.c) -O$O $(CFLAGS_GTEST) $< $(OUTPUT_OPTION)

##
# CmdStan model tests. Adding built model as a dependency.
##
$(patsubst src/%_test.cpp,%.o,$(filter src/test/CmdStan/models/%,$(ALL_TESTS))): test/CmdStan/%.o : %$(EXE)


##
# Agrad distributions test generator
##
test/unit-distribution/generate_tests$(EXE) : src/test/unit-distribution/generate_tests.cpp
	@mkdir -p $(dir $@)
	$(LINK.c) -O$(O_STANC) $(CFLAGS) $< $(OUTPUT_OPTION)

src/test/unit-distribution/%_00000_generated_test.cpp : src/test/unit-distribution/%_test.hpp | test/unit-distribution/generate_tests$(EXE)
	@echo "--- Generating tests for $(notdir $<) ---"
	test/unit-distribution/generate_tests$(EXE) $<




##
# For src/test/unit-distribution tests, adding
# dependency on generated tests.
##

ifneq ($(filter second-expansion,$(.FEATURES)),)

DISTRIBUTION_TESTS := $(shell find src/test/unit-distribution -type f -name '*.hpp')
.SECONDEXPANSION:
$(filter src/test/unit-distribution%,$(TEST_TARGETS)): src/test/unit-distribution%: $$(patsubst $$(PERCENT)_test.hpp,$$(PERCENT)_00000_generated_test.cpp,$$(filter $$@$$(PERCENT),$$(DISTRIBUTION_TESTS)))

endif

##
# Set the variable GENERATE_TESTS to non-empty string
# when the target is generating distribution tests.
# This indicates whether make should be rerun.
#
#   Notes:
#     The first argument to filter-out is the number of unique
#        generated distribution tests that have already been generated
#        in this current run of make. If this is the stage where
#        we are generating tests, this number will be less than the
#        number of tests to generate. (0 if running from a clean state)
#     The second argument to filter-out is the number of unique
#        generated distribution tests that should be generated. 
#        This is determined by the existence of *_test.hpp files in 
#        the appropriate directory.
#     The filter-out function returns the total number of tests that should
#        be generated if they have not yet been generated.
##
$(filter src/test/unit-distribution%,$(TEST_TARGETS)): \
GENERATE_TESTS = $(filter-out $(words $(filter %_00000_generated$(EXE),$^)),\
                              $(words $(filter $@%_00000_generated_test.cpp,$(ALL_TESTS))))


.PHONY: test-headers
test-headers: $(HEADER_TESTS) 

##
# Deprecated test targets
##
.PHONY: test-unit test-distributions test-models test-bugs
test-unit test-distributions test-models test-bugs test-all:
	@echo ''
	@echo ''
	@echo '  The '$@' target is deprecated. Please use these make targets instead:'
	@echo '      '$^

test-unit: src/test/unit src/test/unit-agrad-rev src/test/unit-agrad-fwd

test-distributions: src/test/unit-distribution

test-models: src/test/CmdStan/models

test-bugs: src/test/CmdStan/models/bugs_examples


.PHONY: test-all
test-all: test-headers $(TEST_TARGETS)