cmake_minimum_required(VERSION 3.16)
project(skia_wayland_nodeco LANGUAGES C CXX)

# --- toolchain & opts ---------------------------------------------------------
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)

# --- deps (pkg-config) --------------------------------------------------------
find_package(PkgConfig REQUIRED)
pkg_check_modules(WAYLAND_CLIENT REQUIRED wayland-client)
pkg_check_modules(WAYLAND_EGL REQUIRED wayland-egl)
pkg_check_modules(EGL REQUIRED egl)
pkg_check_modules(GLES2 REQUIRED glesv2)
# Skia package name varies; this works on many distros. Adjust if needed.
pkg_check_modules(SKIA REQUIRED skia)
# The protocol XMLs live here:
pkg_check_modules(WAYLAND_PROTOCOLS REQUIRED wayland-protocols)

# --- scanners -----------------------------------------------------------------
find_program(WAYLAND_SCANNER wayland-scanner REQUIRED)
# waylandpp's generator; provided by the waylandpp package
# (typically installed as 'wayland-scanner++')
find_program(WAYLAND_SCANNER_PP wayland-scanner++ REQUIRED)

# --- protocol XML paths -------------------------------------------------------
pkg_get_variable(WAYLAND_PROTOCOLS_DIR wayland-protocols pkgdatadir)

# fallback via datarootdir if needed
if(NOT WAYLAND_PROTOCOLS_DIR OR NOT EXISTS "${WAYLAND_PROTOCOLS_DIR}/stable/xdg-shell/xdg-shell.xml")
	pkg_get_variable(_WP_DATAROOT wayland-protocols datarootdir)
	if(_WP_DATAROOT AND EXISTS "${_WP_DATAROOT}/wayland-protocols")
		set(WAYLAND_PROTOCOLS_DIR "${_WP_DATAROOT}/wayland-protocols")
	endif()
endif()

# last-resort search (covers odd layouts)
if(NOT WAYLAND_PROTOCOLS_DIR OR NOT EXISTS "${WAYLAND_PROTOCOLS_DIR}/stable/xdg-shell/xdg-shell.xml")
	find_path(WAYLAND_PROTOCOLS_DIR
		NAMES stable/xdg-shell/xdg-shell.xml
		HINTS ${CMAKE_SYSTEM_PREFIX_PATH}
		PATH_SUFFIXES wayland-protocols share/wayland-protocols
	)
endif()

if(NOT WAYLAND_PROTOCOLS_DIR)
	message(FATAL_ERROR "Could not locate wayland-protocols datadir (install wayland-protocols?)")
endif()

set(XDG_SHELL_XML
	"${WAYLAND_PROTOCOLS_DIR}/stable/xdg-shell/xdg-shell.xml"
)
set(XDG_DECOR_XML
	"${WAYLAND_PROTOCOLS_DIR}/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml"
)

# --- generated outputs (into build dir) ---------------------------------------
set(GEN_DIR "${CMAKE_CURRENT_BINARY_DIR}/generated")
file(MAKE_DIRECTORY "${GEN_DIR}")

# waylandpp C++ headers + code (used by the app)
set(GEN_CXX_HEADERS
	"${GEN_DIR}/xdg-shell-client-protocol.hpp"
	"${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.hpp"
)
set(GEN_CXX_SOURCES
	"${GEN_DIR}/xdg-shell-client-protocol.cpp"
	"${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.cpp"
)

# (optional) C headers + private impls (not linked, but generated)
set(GEN_C_HEADERS
	"${GEN_DIR}/xdg-shell-client-protocol.h"
	"${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.h"
)
set(GEN_C_PRIVATES
	"${GEN_DIR}/xdg-shell-protocol.c"
	"${GEN_DIR}/xdg-decoration-unstable-v1-protocol.c"
)

# --- custom commands: generate C++ (required) ---------------------------------
add_custom_command(
	OUTPUT ${GEN_CXX_HEADERS} ${GEN_CXX_SOURCES}
	COMMAND "${WAYLAND_SCANNER_PP}" "${XDG_SHELL_XML}" "${GEN_DIR}/xdg-shell-client-protocol.hpp"                 "${GEN_DIR}/xdg-shell-client-protocol.cpp"
	COMMAND "${WAYLAND_SCANNER_PP}" "${XDG_DECOR_XML}" "${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.hpp" "${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.cpp"
	DEPENDS "${XDG_SHELL_XML}" "${XDG_DECOR_XML}"
	COMMENT "Generating waylandpp C++ protocol headers/sources with wayland-scanner++"
	VERBATIM
)

# --- custom commands: generate C (optional) -----------------------------------
add_custom_command(
	OUTPUT ${GEN_C_HEADERS} ${GEN_C_PRIVATES}
	COMMAND "${WAYLAND_SCANNER}" client-header "${XDG_SHELL_XML}" "${GEN_DIR}/xdg-shell-client-protocol.h"
	COMMAND "${WAYLAND_SCANNER}" private-code  "${XDG_SHELL_XML}" "${GEN_DIR}/xdg-shell-protocol.c"
	COMMAND "${WAYLAND_SCANNER}" client-header "${XDG_DECOR_XML}" "${GEN_DIR}/xdg-decoration-unstable-v1-client-protocol.h"
	COMMAND "${WAYLAND_SCANNER}" private-code  "${XDG_DECOR_XML}" "${GEN_DIR}/xdg-decoration-unstable-v1-protocol.c"
	DEPENDS "${XDG_SHELL_XML}" "${XDG_DECOR_XML}"
	COMMENT "Generating C client headers + private code with wayland-scanner (optional)"
	VERBATIM
)

add_custom_target(generate_protocols ALL
	DEPENDS ${GEN_CXX_HEADERS} ${GEN_CXX_SOURCES} ${GEN_C_HEADERS} ${GEN_C_PRIVATES}
)

# --- executable ---------------------------------------------------------------
add_executable(skia_wayland
	${GEN_CXX_HEADERS}
	${GEN_CXX_SOURCES}

	${CMAKE_CURRENT_SOURCE_DIR}/main.cpp
)
add_dependencies(skia_wayland generate_protocols)

# include dirs (system + generated)
target_include_directories(skia_wayland PRIVATE
	${WAYLAND_CLIENT_INCLUDE_DIRS}
	${WAYLAND_EGL_INCLUDE_DIRS}
	${EGL_INCLUDE_DIRS}
	${GLES2_INCLUDE_DIRS}
	${SKIA_INCLUDE_DIRS}
	# waylandpp headers (wayland-client.hpp). If they aren't system-wide, add your path here:
	# ${CMAKE_CURRENT_SOURCE_DIR}/external/waylandpp/include
	${GEN_DIR}
)

# libs
target_link_libraries(skia_wayland PRIVATE
	${WAYLAND_CLIENT_LIBRARIES}
	${WAYLAND_EGL_LIBRARIES}
	${EGL_LIBRARIES}
	${GLES2_LIBRARIES}
	${SKIA_LIBRARIES}
	# some distros need these as well:
	m
	dl
	pthread
)

# cflags/ldflags from pkg-config
target_compile_options(skia_wayland PRIVATE
	${WAYLAND_CLIENT_CFLAGS_OTHER}
	${WAYLAND_EGL_CFLAGS_OTHER}
	${EGL_CFLAGS_OTHER}
	${GLES2_CFLAGS_OTHER}
	${SKIA_CFLAGS_OTHER}
)
target_link_options(skia_wayland PRIVATE
	${WAYLAND_CLIENT_LDFLAGS_OTHER}
	${WAYLAND_EGL_LDFLAGS_OTHER}
	${EGL_LDFLAGS_OTHER}
	${GLES2_LDFLAGS_OTHER}
	${SKIA_LDFLAGS_OTHER}
)

# --- warnings -----------------------------------------------------------------
if(CMAKE_CXX_COMPILER_ID MATCHES "Clang|GNU")
	target_compile_options(skia_wayland PRIVATE -Wall -Wextra -Wno-unused-parameter)
endif()

# --- install (optional) -------------------------------------------------------
install(TARGETS skia_wayland RUNTIME DESTINATION bin)