#
# Copyright (c) 2019-2020, Arm Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#

include_guard(DIRECTORY)

# Trying to set CLANG_LIBRARY_PATH using the following methods
# 1. Using cache or command line definition
#    Show warning if environment variable is also set but has different value
# 2. Copying the value of CLANG_LIBRARY_PATH environment variable if set
# 3. find_package (llvm-config, common paths or Windows registry)
# If none of the above steps succeeded CMake emits a fatal error and stops

set(CLANG_LIBRARY_PATH_HELP "libclang directory for c-picker")

if (DEFINED CLANG_LIBRARY_PATH)
	message(STATUS "Using CLANG_LIBRARY_PATH from CMake variable (command line or cache)")

	if (DEFINED ENV{CLANG_LIBRARY_PATH})
		if (NOT (${CLANG_LIBRARY_PATH} STREQUAL $ENV{CLANG_LIBRARY_PATH}))
			message(WARNING "Both CLANG_LIBRARY_PATH CMake and environment variables are set but have different values")
		endif()
	endif()
else()
	if (DEFINED ENV{CLANG_LIBRARY_PATH})
		message(STATUS "Setting CLANG_LIBRARY_PATH based on environment variable")
		set(CLANG_LIBRARY_PATH $ENV{CLANG_LIBRARY_PATH} CACHE PATH ${CLANG_LIBRARY_PATH_HELP})
	else()
		message(STATUS "Setting CLANG_LIBRARY_PATH based on find_package")
		find_package(LibClang REQUIRED)
		set(CLANG_LIBRARY_PATH ${LibClang_LIBRARY_DIRS} CACHE PATH ${CLANG_LIBRARY_PATH_HELP})
	endif()
endif()

message(STATUS "CLANG_LIBRARY_PATH has been set to ${CLANG_LIBRARY_PATH}")

# Checking c-picker
find_program(CPICKER_COMMAND "c-picker")
if (NOT CPICKER_COMMAND)
	message(FATAL_ERROR "Please install c-picker using pip")
endif()

# Global dependencies:
#   Variables
#     CPICKER_COMMAND: command of the c-picker
#     CPICKER_CACHE_PATH: root directory of the c-picker generate files
#     UNIT_TEST_COMMON_SOURCES: common source files for every test build
#     CLANG_LIBRARY_PATH: libclang directory for c-picker
#   Modules
#     CTest module should be included in the root CMakeLists.txt before calling this function

function(unit_test_add_suite)
	set(_OPTIONS_ARGS args1)
	set(_ONE_VALUE_ARGS NAME)
	set(_MULTI_VALUE_ARGS SOURCES INCLUDE_DIRECTORIES COMPILE_DEFINITIONS DEPENDS)
	cmake_parse_arguments(_MY_PARAMS "${_OPTIONS_ARGS}" "${_ONE_VALUE_ARGS}" "${_MULTI_VALUE_ARGS}" ${ARGN})
	# TODO: check_args(add_unit_test_suite args1 args2 args3)

	if(NOT DEFINED BUILD_TESTING)
		message(FATAL_ERROR
			"add_unit_test_suite(): "
			"CTest module should be included in the root CMakeLists.txt before calling this function.")
	endif()

	set(TEST_NAME ${_MY_PARAMS_NAME})
	set(TEST_INCLUDE_DIRECTORIES ${_MY_PARAMS_INCLUDE_DIRECTORIES})
	set(TEST_COMPILE_DEFINITIONS ${_MY_PARAMS_COMPILE_DEFINITIONS})
	set(TEST_DEPENDS ${_MY_PARAMS_DEPENDS})

	add_executable(${TEST_NAME} ${UNIT_TEST_COMMON_SOURCES})

	foreach(TEST_SOURCE ${_MY_PARAMS_SOURCES})
		get_filename_component(TEST_SOURCE_EXTENSION ${TEST_SOURCE} EXT)

		if (${TEST_SOURCE_EXTENSION} STREQUAL ".yml")
			# Building output file name: tests/a/b/test.yml -> ${CPICKER_CACHE_PATH}/a/b/test.c
			get_filename_component(TEST_SOURCE_DIR ${TEST_SOURCE} DIRECTORY)
			file(RELATIVE_PATH CPICKER_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/tests ${TEST_SOURCE_DIR})
			get_filename_component(TEST_SOURCE_NAME ${TEST_SOURCE} NAME_WE)
			set(CPICKER_OUTPUT ${CPICKER_CACHE_PATH}/${TEST_NAME}/${CPICKER_SOURCE_DIR}/${TEST_SOURCE_NAME}.c)

			# Creating output directory
			get_filename_component(OUTPUT_DIRECTORY ${CPICKER_OUTPUT} DIRECTORY)
			file(MAKE_DIRECTORY ${OUTPUT_DIRECTORY})

			# Fetching referenced source files as the dependencies of the generated file
			execute_process(
				COMMAND
					${CMAKE_COMMAND} -E env CLANG_LIBRARY_PATH=${CLANG_LIBRARY_PATH}
					${CPICKER_COMMAND} --config ${TEST_SOURCE} --root ${TF_A_PATH} --print-dependencies
				OUTPUT_VARIABLE CPICKER_DEPENDENCIES
			)

			# Adding custom command for invoking c-picker
			add_custom_command(
				OUTPUT ${CPICKER_OUTPUT}
				COMMAND
					${CMAKE_COMMAND} -E env CLANG_LIBRARY_PATH=${CLANG_LIBRARY_PATH}
					${CPICKER_COMMAND} --config ${TEST_SOURCE} --root ${TF_A_PATH} > ${CPICKER_OUTPUT}
				DEPENDS ${TEST_SOURCE} ${CPICKER_DEPENDENCIES}
				COMMENT "Generating c-picker output ${CPICKER_OUTPUT}"
			)
			set(TEST_SOURCE ${CPICKER_OUTPUT})
		endif()

		target_sources(${TEST_NAME} PRIVATE ${TEST_SOURCE})
	endforeach()

	target_include_directories(${TEST_NAME} PRIVATE ${TEST_INCLUDE_DIRECTORIES})
	target_compile_definitions(${TEST_NAME} PRIVATE ${TEST_COMPILE_DEFINITIONS})
	if (TEST_DEPENDS)
		add_dependencies(${TEST_NAME} ${TEST_DEPENDS})
	endif()
	add_test(${TEST_NAME} ${TEST_NAME})
endfunction()