find_program(IFC
	NAMES ifc
	REQUIRED
	HINTS ${BUILD_TOOLS_DIR})
message(STATUS "Found interface compiler: ${IFC}")

function(add_interface)
	set(options)
	set(one_value_args NAME PARENT_DIR PATH)
	set(multi_value_args)

	cmake_parse_arguments(PARSE_ARGV 0 arg
		"${options}"
		"${one_value_args}"
		"${multi_value_args}")

	message(STATUS "Building interface ${arg_NAME}")
	file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${arg_PARENT_DIR})
	set(header_path ${CMAKE_CURRENT_BINARY_DIR}/${arg_PARENT_DIR}/${arg_NAME}.h)

	add_custom_command(
		OUTPUT ${header_path}
		COMMAND	${IFC} ${arg_PATH}
		WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${arg_PARENT_DIR}
		COMMENT "Compiling interface: ${arg_NAME}")

	add_custom_target(ifgen-${arg_NAME} ALL
		DEPENDS ${header_path})

	set_target_properties(ifgen-${arg_NAME} PROPERTIES
		iface_header_path ${header_path}
		iface_parent_dir ${arg_PARENT_DIR})

	add_library(iflib-${arg_NAME} INTERFACE)
	set_target_properties(iflib-${arg_NAME} PROPERTIES
		INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_BINARY_DIR})
	add_dependencies(iflib-${arg_NAME} ifgen-${arg_NAME})
	add_library(interface::${arg_NAME} ALIAS iflib-${arg_NAME})
endfunction(add_interface)

function(iface_get_header_path)
	set(options)
	set(one_value_args NAME OUT)
	set(multi_value_args)

	cmake_parse_arguments(PARSE_ARGV 0 arg
		"${options}"
		"${one_value_args}"
		"${multi_value_args}")

	get_property(
		value
		TARGET ifgen-${name}
		PROPERTY iface_header_path)

	set(${arg_OUT} ${value} PARENT_SCOPE)
endfunction(iface_get_header_path)

function(iface_get_parent_dir)
	set(options)
	set(one_value_args NAME OUT)
	set(multi_value_args)

	cmake_parse_arguments(PARSE_ARGV 0 arg
		"${options}"
		"${one_value_args}"
		"${multi_value_args}")

	get_property(
		value
		TARGET ifgen-${name}
		PROPERTY iface_parent_dir)

	set(${arg_OUT} ${value} PARENT_SCOPE)
endfunction(iface_get_parent_dir)