#    Copyright (C) 2012 Modelon AB

#    This program is free software: you can redistribute it and/or modify

#    it under the terms of the BSD style license.

#    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

#    FMILIB_License.txt file for more details.

#    You should have received a copy of the FMILIB_License.txt file

#    along with this program. If not, contact Modelon AB <http://www.modelon.com>.

# Merge_static_libs(output_library lib1 lib2 ... libn) merges a number of static

# libs into a single static library

function(merge_static_libs output_library)

	set(output_target "${output_library}")

	string(REGEX REPLACE "-" "_" output_library ${output_library})

	set(libs ${ARGV})

	list(REMOVE_AT libs 0)

	# Create a dummy file that the target will depend on

	set(dummyfile ${CMAKE_CURRENT_BINARY_DIR}/${output_library}_dummy.c)

	file(WRITE ${dummyfile} "const char * dummy = \"${dummyfile}\";")

	add_library(${output_target} STATIC ${dummyfile})

	if("${CMAKE_CFG_INTDIR}" STREQUAL ".")

		set(multiconfig FALSE)

	else()

		set(multiconfig TRUE)

	endif()

	# First get the file names of the libraries to be merged	

	foreach(lib ${libs})

		get_target_property(libtype ${lib} TYPE)

		if(NOT libtype STREQUAL "STATIC_LIBRARY")

			message(FATAL_ERROR "Merge_static_libs can only process static libraries")

		endif()

		if(multiconfig)

			foreach(CONFIG_TYPE ${CMAKE_CONFIGURATION_TYPES})

				get_target_property("libfile_${CONFIG_TYPE}" ${lib} "LOCATION_${CONFIG_TYPE}")

				list(APPEND libfiles_${CONFIG_TYPE} ${libfile_${CONFIG_TYPE}})

			endforeach()

		else()

			get_target_property(libfile ${lib} LOCATION)

			list(APPEND libfiles "${libfile}")

		endif(multiconfig)

	endforeach()

	# Just to be sure: cleanup from duplicates

	if(multiconfig)	

		foreach(CONFIG_TYPE ${CMAKE_CONFIGURATION_TYPES})

			list(REMOVE_DUPLICATES libfiles_${CONFIG_TYPE})

			set(libfiles ${libfiles} ${libfiles_${CONFIG_TYPE}})

		endforeach()

	endif()

	list(REMOVE_DUPLICATES libfiles)

	# Now the easy part for MSVC and for MAC

  if(MSVC)

    # lib.exe does the merging of libraries just need to conver the list into string

	foreach(CONFIG_TYPE ${CMAKE_CONFIGURATION_TYPES})

		set(flags "")

		foreach(lib ${libfiles_${CONFIG_TYPE}})

			set(flags "${flags} ${lib}")

		endforeach()

		string(TOUPPER "STATIC_LIBRARY_FLAGS_${CONFIG_TYPE}" PROPNAME)

		set_target_properties(${output_target} PROPERTIES ${PROPNAME} "${flags}")

	endforeach()

  elseif(APPLE)

    # Use OSX's libtool to merge archives

	if(multiconfig)

		message(FATAL_ERROR "Multiple configurations are not supported")

	endif()

	get_target_property(outfile ${output_target} LOCATION)  

	add_custom_command(TARGET ${output_target} POST_BUILD

		COMMAND rm ${outfile}

		COMMAND /usr/bin/libtool -static -o ${outfile} 

		${libfiles}

	)

  else() 

  # general UNIX - need to "ar -x" and then "ar -ru"

	if(multiconfig)

		message(FATAL_ERROR "Multiple configurations are not supported")

	endif()

	get_target_property(outfile ${output_target} LOCATION)

	message(STATUS "output file location is ${outfile}")

	foreach(lib ${libfiles})

		# objlistfile will contain the list of object files for the library

		set(objlistfile ${lib}.objlist)

		set(objdir ${lib}.objdir)

		set(objlistcmake  ${objlistfile}.cmake)

		get_filename_component(libname ${lib} NAME_WE)

		if(${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/cmake.check_cache IS_NEWER_THAN ${objlistcmake})

			file(WRITE ${objlistcmake} "

				# delete previous object files

				message(STATUS \"Removing previous object files from ${lib}\")

				EXECUTE_PROCESS(COMMAND ls .

					WORKING_DIRECTORY ${objdir}

					COMMAND xargs -I {} rm {}

					WORKING_DIRECTORY ${objdir})

				# Extract object files from the library

				message(STATUS \"Extracting object files from ${lib}\")

				EXECUTE_PROCESS(COMMAND ${CMAKE_AR} -x ${lib}

					WORKING_DIRECTORY ${objdir})

				# Prefixing object files to avoid conflicts

				message(STATUS \"Prefixing object files to avoid conflicts\")

				EXECUTE_PROCESS(COMMAND ls .

					WORKING_DIRECTORY ${objdir}

					COMMAND xargs -I {} mv {} ${libname}_{}

					WORKING_DIRECTORY ${objdir})

				# save the list of object files

				EXECUTE_PROCESS(COMMAND ls . 

					OUTPUT_FILE ${objlistfile}

					WORKING_DIRECTORY ${objdir})

			")

			file(MAKE_DIRECTORY ${objdir})

			add_custom_command(

				OUTPUT ${objlistfile}

				COMMAND ${CMAKE_COMMAND} -P ${objlistcmake}

				DEPENDS ${lib})

		endif()

		list(APPEND extrafiles "${objlistfile}")

		# relative path is needed by ar under MSYS

		file(RELATIVE_PATH objlistfilerpath ${objdir} ${objlistfile})

		add_custom_command(TARGET ${output_target} POST_BUILD

			COMMAND ${CMAKE_COMMAND} -E echo "Running: ${CMAKE_AR} ru ${outfile} @${objlistfilerpath}"

			COMMAND ${CMAKE_AR} ru "${outfile}" @"${objlistfilerpath}"

			#COMMAND ld -r -static -o "${outfile}" --whole-archive @"${objlistfilerpath}"

			WORKING_DIRECTORY ${objdir})

	endforeach()

	add_custom_command(TARGET ${output_target} POST_BUILD

			COMMAND ${CMAKE_COMMAND} -E echo "Running: ${CMAKE_RANLIB} ${outfile}"

			COMMAND ${CMAKE_RANLIB} ${outfile})

  endif()

  file(WRITE ${dummyfile}.base "const char* ${output_library}_sublibs=\"${libs}\";")

  add_custom_command( 

		OUTPUT ${dummyfile}

		COMMAND ${CMAKE_COMMAND} -E copy ${dummyfile}.base ${dummyfile}

		DEPENDS ${libs} ${extrafiles})

endfunction()