#/
# @license Apache-2.0
#
# Copyright (c) 2017 The Stdlib Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#/

# VARIABLES #

# Define the download URL:
DEPS_OPENBLAS_URL ?= https://github.com/OpenMathLib/OpenBLAS/archive/v$(DEPS_OPENBLAS_VERSION).tar.gz

# Determine the basename for the download:
deps_openblas_basename := openblas_$(deps_openblas_version_slug).tar.gz

# Define the path to the file containing a checksum to verify a download:
DEPS_OPENBLAS_CHECKSUM ?= $(shell $(CAT) $(DEPS_CHECKSUMS_DIR)/$(subst .,_,$(deps_openblas_basename))/sha256)

# Define the output path when downloading:
DEPS_OPENBLAS_DOWNLOAD_OUT ?= $(DEPS_TMP_DIR)/$(deps_openblas_basename)

# Define the output path after extracting:
deps_openblas_extract_out := $(DEPS_BUILD_DIR)/OpenBLAS-$(DEPS_OPENBLAS_VERSION)

# Define the path to the directory containing tests:
DEPS_OPENBLAS_TEST_DIR ?= $(DEPS_DIR)/test/openblas

# Define the output directory path for compiled tests:
DEPS_OPENBLAS_TEST_OUT ?= $(DEPS_OPENBLAS_TEST_DIR)/build

# Define the path to a test file for checking an installation:
DEPS_OPENBLAS_TEST_INSTALL ?= $(DEPS_OPENBLAS_TEST_DIR)/test_install.c

# Define the output path for a test file:
DEPS_OPENBLAS_TEST_INSTALL_OUT ?= $(DEPS_OPENBLAS_TEST_OUT)/test_install

# Define build options (originally based on Julia; see https://github.com/JuliaLang/julia/blob/master/deps/blas.mk):
DEPS_OPENBLAS_BUILD_OPTS := \
	CC="$(CC)" \
	FC="$(FC)" \
	RANLIB="$(RANLIB)" \
	CFLAGS="$(DEPS_OPENBLAS_CFLAGS)" \
	FFLAGS="$(DEPS_OPENBLAS_FFLAGS)" \
	TARGET="$(DEPS_OPENBLAS_TARGET_ARCH)" \
	BINARY="$(DEPS_OPENBLAS_BINARY)"

# Define threading options:
ifeq ($(DEPS_OPENBLAS_USE_THREAD), 1)
	DEPS_OPENBLAS_BUILD_OPTS += USE_THREAD=1

	# If any `gemm` argument `m`, `n` or `k` is less or equal a provided threshold, `gemm` will be execute using a single thread. This flag is used to avoid the overhead of multi-threading in small matrix sizes. The default value is 4.
	DEPS_OPENBLAS_BUILD_OPTS += GEMM_MULTITHREADING_THRESHOLD=50

# Determine the maximum number of threads (which should be less than the number of cores) for parallelism:
ifneq ($(DEPS_OPENBLAS_ARCH), x86_64)
	# 1) We assume that limited memory will restrict the number of threads we can spawn.
	# 2) 32-bit architectures are likely to have fewer cores.
	DEPS_OPENBLAS_BUILD_OPTS += NUM_THREADS=8
else
ifeq ($(OS), WINNT)
	# Windows does not seem capable of handling many threads:
	DEPS_OPENBLAS_BUILD_OPTS += NUM_THREADS=16
else
ifeq ($(OS), Darwin)
	# 16 threads should suffice for the largest Macs:
	DEPS_OPENBLAS_BUILD_OPTS += NUM_THREADS=16
else
	# For Linux, we try to account for (currently) the largest possible machine:
	DEPS_OPENBLAS_BUILD_OPTS += NUM_THREADS=16
endif # OS==Darwin
endif # OS==WINNT
endif # ARCH!=x86_64
else
	DEPS_OPENBLAS_BUILD_OPTS += USE_THREAD=0
endif

# Disable CPU/memory (scheduler) affinity on Linux:
DEPS_OPENBLAS_BUILD_OPTS += NO_AFFINITY=1

# Determine whether to build for multiple architectures in a single binary:
ifeq ($(DEPS_OPENBLAS_DYNAMIC_ARCH), 1)
	DEPS_OPENBLAS_BUILD_OPTS += DYNAMIC_ARCH=1
else
	DEPS_OPENBLAS_BUILD_OPTS += DYNAMIC_ARCH=0
endif

# Determine whether to compile a debug build:
ifeq ($(DEPS_OPENBLAS_DEBUG), 1)
	DEPS_OPENBLAS_BUILD_OPTS += DEBUG=1
endif

# Allow disabling AVX for older `binutils`:
ifeq ($(DEPS_OPENBLAS_NO_AVX), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_AVX=1 NO_AVX2=1 NO_AVX512=1
else
ifeq ($(DEPS_OPENBLAS_NO_AVX2), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_AVX2=1 NO_AVX512=1
else
ifeq ($(DEPS_OPENBLAS_NO_AVX512), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_AVX512=1
endif
endif
endif

# Determine whether to compile the CBLAS interface:
ifeq ($(DEPS_OPENBLAS_NO_CBLAS), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_CBLAS=1
endif

# Determine whether to only compile the CBLAS interface:
ifeq ($(DEPS_OPENBLAS_ONLY_CBLAS), 1)
	DEPS_OPENBLAS_BUILD_OPTS += ONLY_CBLAS=1
endif

# Determine whether to compile LAPACK:
ifeq ($(DEPS_OPENBLAS_NO_LAPACK), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_LAPACK=1
endif

# Determine whether to compile the C interface to LAPACK:
ifeq ($(DEPS_OPENBLAS_NO_LAPACKE), 1)
	DEPS_OPENBLAS_BUILD_OPTS += NO_LAPACKE=1
endif

# Determine whether to build a 64-bit BLAS interface:
ifeq ($(DEPS_OPENBLAS_USE_BLAS64), 1)
	DEPS_OPENBLAS_BUILD_OPTS += INTERFACE64=1 SYMBOLSUFFIX="$(DEPS_OPENBLAS_SYMBOLSUFFIX)" SYMBOLPREFIX="$(DEPS_OPENBLAS_SYMBOLPREFIX)"
endif

# Do not allow overwriting the `-j` flag which specifies the number of `make` jobs:
DEPS_OPENBLAS_BUILD_OPTS += MAKE_NB_JOBS=0


# RULES #

#/
# Downloads an OpenBLAS distribution.
#
# @private
#/
$(DEPS_OPENBLAS_DOWNLOAD_OUT): | $(DEPS_TMP_DIR)
	$(QUIET) echo 'Downloading OpenBLAS...' >&2
	$(QUIET) $(DEPS_DOWNLOAD_BIN) $(DEPS_OPENBLAS_URL) $(DEPS_OPENBLAS_DOWNLOAD_OUT)

#/
# Extracts an OpenBLAS gzipped tar archive.
#
# @private
#/
$(DEPS_OPENBLAS_BUILD_OUT): $(DEPS_OPENBLAS_DOWNLOAD_OUT) | $(DEPS_BUILD_DIR)
	$(QUIET) echo 'Extracting OpenBLAS...' >&2
	$(QUIET) $(TAR) -zxf $(DEPS_OPENBLAS_DOWNLOAD_OUT) -C $(DEPS_BUILD_DIR)
	$(QUIET) mv $(deps_openblas_extract_out) $(DEPS_OPENBLAS_BUILD_OUT)

#/
# Creates a directory for storing compiled OpenBLAS tests.
#
# @private
#/
$(DEPS_OPENBLAS_TEST_OUT):
	$(QUIET) $(MKDIR_RECURSIVE) $(DEPS_OPENBLAS_TEST_OUT)

#/
# Compiles a test file for testing an OpenBLAS installation.
#
# @private
#/
$(DEPS_OPENBLAS_TEST_INSTALL_OUT): $(DEPS_OPENBLAS_BUILD_OUT) $(DEPS_OPENBLAS_TEST_OUT)
	$(QUIET) $(CC) $(DEPS_OPENBLAS_TEST_INSTALL) -o $(DEPS_OPENBLAS_TEST_INSTALL_OUT) -I $(DEPS_OPENBLAS_BUILD_OUT) -L $(DEPS_OPENBLAS_BUILD_OUT) -lopenblas -lpthread

#/
# Downloads an OpenBLAS distribution.
#
# @private
#
# @example
# make deps-download-openblas
#/
deps-download-openblas: $(DEPS_OPENBLAS_DOWNLOAD_OUT)

.PHONY: deps-download-openblas

#/
# Verifies a download.
#
# @private
#
# @example
# make deps-verify-openblas
#/
deps-verify-openblas: deps-download-openblas
	$(QUIET) echo 'Verifying download...' >&2
	$(QUIET) $(DEPS_CHECKSUM_BIN) $(DEPS_OPENBLAS_DOWNLOAD_OUT) $(DEPS_OPENBLAS_CHECKSUM) >&2

.PHONY: deps-verify-openblas

#/
# Extracts an OpenBLAS download.
#
# @private
#
# @example
# make deps-extract-openblas
#/
deps-extract-openblas: $(DEPS_OPENBLAS_BUILD_OUT)

.PHONY: deps-extract-openblas

#/
# Installs OpenBLAS.
#
# @private
#
# @example
# make deps-install-openblas
#/
deps-install-openblas: $(DEPS_OPENBLAS_BUILD_OUT)
	$(QUIET) $(MAKE) --directory="$(DEPS_OPENBLAS_BUILD_OUT)" $(DEPS_OPENBLAS_BUILD_OPTS)

.PHONY: deps-install-openblas

#/
# Tests an OpenBLAS installation.
#
# @private
#
# @example
# make deps-test-openblas
#/
deps-test-openblas: $(DEPS_OPENBLAS_TEST_INSTALL_OUT)
	$(QUIET) echo 'Running tests...' >&2
	$(QUIET) $(DEPS_OPENBLAS_TEST_INSTALL_OUT)
	$(QUIET) echo '' >&2
	$(QUIET) echo 'Success.' >&2

.PHONY: deps-test-openblas

#/
# Installs OpenBLAS.
#
# @example
# make install-deps-openblas
#/
install-deps-openblas: deps-download-openblas deps-verify-openblas deps-extract-openblas deps-install-openblas deps-test-openblas

.PHONY: install-deps-openblas

#/
# Removes an OpenBLAS distribution (but does not remove an OpenBLAS download if one exists).
#
# @example
# make clean-deps-openblas
#/
clean-deps-openblas: clean-deps-openblas-tests
	$(QUIET) $(DELETE) $(DELETE_FLAGS) $(DEPS_OPENBLAS_BUILD_OUT)

.PHONY: clean-deps-openblas

#/
# Removes OpenBLAS installation test artifacts.
#
# @example
# make clean-deps-openblas-tests
#/
clean-deps-openblas-tests:
	$(QUIET) $(DELETE) $(DELETE_FLAGS) $(DEPS_OPENBLAS_TEST_OUT)

.PHONY: clean-deps-openblas-tests