# Findw32-pthreads.cmake -- last-resort fallback, Windows only.
#
# WHY THIS EXISTS
#
# obs-studio's libobs links `PUBLIC OBS::w32-pthreads` on Windows
# (libobs/cmake/os-windows.cmake), so the libobsConfig.cmake it installs
# carries an unconditional, REQUIRED dependency on a findable `w32-pthreads`
# CMake package:
#
#   if(MSVC)
#     find_dependency(w32-pthreads REQUIRED)
#   endif()
#
# obs-studio *does* export that package -- deps/w32-pthreads/CMakeLists.txt
# ends in `target_export(w32-pthreads)` -- but it exports it to
# <prefix>/cmake/w32-pthreads/, the same OBS_CMAKE_DESTINATION shape that
# find_package's Config-mode search suffixes never look at. The top-level
# CMakeLists.txt therefore points `w32-pthreads_DIR` straight at it, exactly
# as it already does for `libobs_DIR`, and that is the path this build is
# expected to take.
#
# This module is only reached when that export is genuinely absent from
# .deps/ -- for instance if a future obs-studio changes where or whether
# deps/w32-pthreads installs its package, or if the tolerated
# UI/obs-frontend-api install error in
# cmake/common/buildspec_common.cmake::_setup_obs_studio ever starts aborting
# the install *before* libobs's own subtree instead of after it. In that case
# the alternative is a hard configure failure inside libobsConfig.cmake with
# no plugin module built at all, so reconstructing the imported target by
# hand from artifacts the bootstrap definitely produced is strictly better.
#
# It deliberately lives in cmake/windows/find-fallback/ and NOT in
# cmake/windows/, which cmake/common/osconfig.cmake puts on CMAKE_MODULE_PATH
# for every Windows configure. A Findw32-pthreads.cmake on the default module
# path would win over OBS's own exported package on every single build
# (find_package tries MODULE mode before CONFIG mode), permanently replacing
# upstream's real export metadata with this approximation. The top-level
# CMakeLists.txt appends this directory to CMAKE_MODULE_PATH only when it has
# already established that the real export is missing.
#
# Nothing outside Windows ever loads this: the find_dependency above is
# inside `if(MSVC)`, and the CMAKE_MODULE_PATH append that exposes this file
# is inside `if(OS_WINDOWS ...)`.

if(TARGET OBS::w32-pthreads)
  set(w32-pthreads_FOUND TRUE)
  return()
endif()

# Resolve paths from this file's own location rather than
# CMAKE_CURRENT_SOURCE_DIR: a find module runs in whatever scope called
# find_package, and here that call comes from inside libobsConfig.cmake.
# <repo>/cmake/windows/find-fallback/ -> <repo>
get_filename_component(_w32pt_repo_root "${CMAKE_CURRENT_LIST_DIR}/../../.." ABSOLUTE)
set(_w32pt_deps "${_w32pt_repo_root}/.deps")

# Search order, both from obs-studio's own Windows layout:
#   1. the bootstrap's install prefix -- obs-studio/cmake/windows/defaults.cmake
#      sets OBS_LIBRARY_DESTINATION=lib (ARCHIVE, i.e. the import library),
#      OBS_EXECUTABLE_DESTINATION=bin/64bit (RUNTIME, i.e. the DLL) and
#      OBS_INCLUDE_DESTINATION=include (where target_export installs
#      w32-pthreads' PUBLIC_HEADER pthread.h/sched.h);
#   2. the obs-studio build tree the bootstrap just built in, in case the
#      install step is what failed rather than the export.
file(GLOB _w32pt_build_trees "${_w32pt_deps}/obs-studio-*/build_*/deps/w32-pthreads/Release")
file(GLOB _w32pt_source_trees "${_w32pt_deps}/obs-studio-*/deps/w32-pthreads")

find_library(
  w32-pthreads_IMPLIB
  NAMES w32-pthreads
  PATHS "${_w32pt_deps}/lib" ${_w32pt_build_trees}
  NO_DEFAULT_PATH
)
find_file(
  w32-pthreads_RUNTIME_LIBRARY
  NAMES w32-pthreads.dll
  PATHS "${_w32pt_deps}/bin/64bit" ${_w32pt_build_trees}
  NO_DEFAULT_PATH
)
find_path(
  w32-pthreads_INCLUDE_DIR
  NAMES pthread.h
  PATHS "${_w32pt_deps}/include" ${_w32pt_source_trees}
  NO_DEFAULT_PATH
)

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(
  w32-pthreads
  REQUIRED_VARS w32-pthreads_IMPLIB w32-pthreads_INCLUDE_DIR
  REASON_FAILURE_MESSAGE
    "The OBS SDK bootstrap neither exported a w32-pthreads CMake package under ${_w32pt_deps}/cmake/ nor left a w32-pthreads import library anywhere under ${_w32pt_deps}."
)

if(w32-pthreads_FOUND)
  # SHARED, matching deps/w32-pthreads/CMakeLists.txt's own
  # `add_library(w32-pthreads SHARED ...)`. IMPORTED_LOCATION is the DLL and
  # IMPORTED_IMPLIB the .lib, which is what an imported SHARED library means
  # on Windows; if only the .lib was found, declare it UNKNOWN instead so
  # CMake does not demand a DLL it will never be handed.
  if(w32-pthreads_RUNTIME_LIBRARY)
    add_library(OBS::w32-pthreads SHARED IMPORTED)
    set_target_properties(
      OBS::w32-pthreads
      PROPERTIES IMPORTED_LOCATION "${w32-pthreads_RUNTIME_LIBRARY}" IMPORTED_IMPLIB "${w32-pthreads_IMPLIB}"
    )
  else()
    add_library(OBS::w32-pthreads UNKNOWN IMPORTED)
    set_target_properties(OBS::w32-pthreads PROPERTIES IMPORTED_LOCATION "${w32-pthreads_IMPLIB}")
  endif()
  set_target_properties(
    OBS::w32-pthreads
    PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${w32-pthreads_INCLUDE_DIR}"
  )
  message(STATUS "Findw32-pthreads (fallback): OBS::w32-pthreads -> ${w32-pthreads_IMPLIB}")
endif()

mark_as_advanced(w32-pthreads_IMPLIB w32-pthreads_RUNTIME_LIBRARY w32-pthreads_INCLUDE_DIR)