# 3 june 2016
# see https://cmake.org/gitweb?p=cmake.git;a=commit;h=95cdf132489c79e88a10fdf7a7566fa002c7680b (thanks ngladitz in irc.freenode.net/#cmake)
cmake_minimum_required(VERSION 3.1.0 FATAL_ERROR)

# TODOs
# - silence entering/leaving messages?
# - uname -s for more refined OS control
# 	- Haiku for haiku
# - debian DESTDIR? https://github.com/andlabs/libui/pull/10
# - libui-combined* needs to be deleted so that custom command can run every time
# - add notelemetry.obj to *ALL TARGETS* on VS2015 and up - https://www.infoq.com/news/2016/06/visual-cpp-telemetry
# - switch to 3.1.0 features

# the docs say we need to set this up prior to project()
# the docs don't say this, but the CACHE part is important; see https://stackoverflow.com/questions/34208360/cmake-seems-to-ignore-cmake-osx-deployment-target
# TODO figure out what other variables must be set with CACHE
# TODO figure out if FORCE is needed here
# TODO figure out whether STRING "" is best or if something else is better; also what FORCE does because I forget and later I say it's needed
set(CMAKE_OSX_DEPLOYMENT_TARGET "10.8" CACHE STRING "" FORCE)

# we want to disable incremental linking
# see also:
# - https://github.com/bulletphysics/bullet3/blob/master/CMakeLists.txt#L43
# - https://cmake.org/pipermail/cmake/2010-February/035174.html
# this must also go before project()
set(MSVC_INCREMENTAL_DEFAULT ON)

# default to debug builds
# do this before project() just to be safe
if(NOT CMAKE_BUILD_TYPE)
	set(CMAKE_BUILD_TYPE DEBUG CACHE STRING "" FORCE)
endif()

project(libui)
option(BUILD_SHARED_LIBS "Whether to build libui as a shared library or a static library" ON)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/out")
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/out")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/out")
set(CMAKE_PDB_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/out")

if(APPLE)
	set(_OSNAME darwin)
	set(_HASVERSION TRUE)
	set(_VERSION "A")

	# always use our rpath
	set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
	# the / is required by some older versions of OS X
	set(CMAKE_INSTALL_RPATH "@executable_path/")
	set(CMAKE_MACOSX_RPATH TRUE)
elseif(WIN32)
	set(_OSNAME windows)

	# and don't include the default libraries with ANY of the builds
	# note the CACHE FORCE stuff is required here
	set(CMAKE_C_STANDARD_LIBRARIES CACHE STRING "" FORCE)
	set(CMAKE_CXX_STANDARD_LIBRARIES CACHE STRING "" FORCE)
else()
	set(_OSNAME unix)
	set(_HASVERSION TRUE)
	set(_VERSION "0")

	# always use our rpath
	set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
	set(CMAKE_INSTALL_RPATH "\$ORIGIN")
endif()

# common flags
if(MSVC)
	# TODO subsystem version

	# TODO /Wall does too much
	# TODO -Wno-switch equivalent
	# TODO /sdl turns C4996 into an ERROR
	# don't use /analyze; that requires us to write annotations everywhere
	# TODO undecided flags from qo?
	# /RTCc is not supplied because it's discouraged as of VS2015; see https://www.reddit.com/r/cpp/comments/46mhne/rtcc_rejects_conformant_code_with_visual_c_2015/d06auq5
	# /EHsc is to shut the compiler up in some cases
	# TODO make /EHsc C++-only
	set(_COMMON_CFLAGS
		/W4 /wd4100
		/bigobj /nologo
		/RTC1 /RTCs /RTCu
		/EHsc
	)

	# note the /MANIFEST:NO (which must be / and uppercase); thanks FraGag (https://github.com/andlabs/libui/issues/93#issuecomment-223183436)
	# TODO warnings on undefined symbols
	set(_COMMON_LDFLAGS
		/LARGEADDRESSAWARE
		/NOLOGO
		/INCREMENTAL:NO
		/MANIFEST:NO
	)

	# TODO autogenerate a .def file?

	# more incremental linking fixes
	# TODO actually get rid of incremental linking here
else()
	set(_COMMON_CFLAGS
		-Wall -Wextra -pedantic
		-Wno-unused-parameter
		-Wno-switch
		-fvisibility=hidden
	)
	# don't use C_VERSION or CXX_VERSION because they use GNU standards
	# TODO we can actually do this; set both C_EXTENSIONS and CXX_EXTENSIONS to OFF
	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --std=c99")
	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --std=c++11")

	set(_COMMON_LDFLAGS
		-fvisibility=hidden
	)

	# don't require shipping the MinGW-w64 DLLs
	if(WIN32)
		list(APPEND _COMMON_LDFLAGS
			-static
			-static-libgcc
			-static-libstdc++
		)
	endif()

	# TODO document this
	if(ADDRESS_SANITIZER)
		set(_COMMON_CFLAGS ${_COMMON_CFLAGS}
			-fsanitize=address
			-fno-omit-frame-pointer
		)
		set(_COMMON_LDFLAGS ${_COMMON_LDFLAGS}
			-fsanitize=address
			-fno-omit-frame-pointer
		)
	endif()
endif()

# problem:
# - target_link_libraries() only supports - for flags
# - but cmake only doesn't generate the manifest if the flag has a /
macro(_target_link_options_private _target)
	foreach(_opt IN LISTS ${ARGN})
		set_property(TARGET ${_target} APPEND_STRING PROPERTY
			LINK_FLAGS " ${_opt}")
	endforeach()
endmacro()

add_subdirectory("common")
add_subdirectory("${_OSNAME}")
add_library(libui ${_LIBUI_SOURCES})
target_include_directories(libui
	PUBLIC .
	PRIVATE ${_LIBUI_INCLUEDIRS})
target_compile_definitions(libui
	PRIVATE ${_LIBUI_DEFS})
# cmake produces this for us by default but only for shared libraries
target_compile_definitions(libui
	PRIVATE libui_EXPORTS)
target_compile_options(libui
	PUBLIC ${_COMMON_CFLAGS}
	PRIVATE ${_LIBUI_CFLAGS})
# TODO link directories?
if(BUILD_SHARED_LIBS)
	target_link_libraries(libui
		PRIVATE ${_LIBUI_LIBS})
endif()
# TODO INTERFACE libs don't inherit to grandhcildren?
# on Windows the linker for static libraries is different; don't give it the flags
if(BUILD_SHARED_LIBS)
	_target_link_options_private(libui
		_COMMON_LDFLAGS
		_LIBUI_LDFLAGS)
endif()
if(NOT BUILD_SHARED_LIBS)
	# TODO figure out a way to tell libui that it's static
	target_compile_definitions(libui
		PUBLIC _UI_STATIC)
endif()
if(NOT MSVC)
	# on non-MSVC compilers cmake adds an extra lib-
	# note that we apply this to libui, not to any intermediates
	set_target_properties(libui PROPERTIES
		OUTPUT_NAME ui)

	# flags for warning on undefined symbols
	# TODO figure out why FreeBSD follows linked libraries here
	# TODO figure out MSVC equivalents
	if(BUILD_SHARED_LIBS)
		if(NOT (${CMAKE_SYSTEM_NAME} STREQUAL FreeBSD))
			# on OS X we don't need to do this; Apple's linker warns about undefined symbols in -shared builds!
			if(NOT APPLE)
				target_link_libraries(libui
					PRIVATE -Wl,--no-undefined -Wl,--no-allow-shlib-undefined
				)
			endif()
		endif()
	endif()
endif()
if(BUILD_SHARED_LIBS)
	if(_HASVERSION)
		set_target_properties(libui PROPERTIES
			SOVERSION "${_VERSION}")
	endif()
endif()

macro(_add_exec _name)
	# TODOTODO re-add WIN32 when merging back
	add_executable(${_name}
		EXCLUDE_FROM_ALL
		${ARGN})
	target_link_libraries(${_name} libui)
	_target_link_options_private(${_name}
		_COMMON_LDFLAGS)
	# make shared-linked executables PIC too
	if(BUILD_SHARED_LIBS)
		set_property(TARGET ${_name} PROPERTY
			POSITION_INDEPENDENT_CODE True)
	endif()
	# TODO see above about INTERFACE
	if(NOT BUILD_SHARED_LIBS)
		target_link_libraries(${_name}
			${_LIBUI_LIBS})
	endif()

	# TODOfor some reason these don't propagate
	if(NOT WIN32)
		target_include_directories(${_name}
			PUBLIC .)
		target_compile_options(${_name}
			PUBLIC ${_COMMON_CFLAGS})
	endif()
endmacro()
add_subdirectory("test")
add_subdirectory("examples")