# Copyright Contributors to the OpenVDB Project
# SPDX-License-Identifier: MPL-2.0
#
#[=======================================================================[.rst:

FindIlmBase
-----------

Find IlmBase include dirs and libraries

Use this module by invoking find_package with the form::

  find_package(IlmBase
    [version] [EXACT]      # Minimum or EXACT version
    [REQUIRED]             # Fail with error if IlmBase is not found
    [COMPONENTS <libs>...] # IlmBase libraries by their canonical name
                           # e.g. "Half" for "libHalf"
    )

IMPORTED Targets
^^^^^^^^^^^^^^^^

``IlmBase::Half``
  The Half library target.
``IlmBase::Iex``
  The Iex library target.
``IlmBase::IexMath``
  The IexMath library target.
``IlmBase::IlmThread``
  The IlmThread library target.
``IlmBase::Imath``
  The Imath library target.

Result Variables
^^^^^^^^^^^^^^^^

This will define the following variables:

``IlmBase_FOUND``
  True if the system has the IlmBase library.
``IlmBase_VERSION``
  The version of the IlmBase library which was found.
``IlmBase_INCLUDE_DIRS``
  Include directories needed to use IlmBase.
``IlmBase_LIBRARIES``
  Libraries needed to link to IlmBase.
``IlmBase_LIBRARY_DIRS``
  IlmBase library directories.
``IlmBase_{COMPONENT}_FOUND``
  True if the system has the named IlmBase component.

Cache Variables
^^^^^^^^^^^^^^^

The following cache variables may also be set:

``IlmBase_INCLUDE_DIR``
  The directory containing ``IlmBase/config-auto.h``.
``IlmBase_{COMPONENT}_LIBRARY``
  Individual component libraries for IlmBase

Hints
^^^^^

Instead of explicitly setting the cache variables, the following variables
may be provided to tell this module where to look.

``IlmBase_ROOT``
  Preferred installation prefix.
``ILMBASE_INCLUDEDIR``
  Preferred include directory e.g. <prefix>/include
``ILMBASE_LIBRARYDIR``
  Preferred library directory e.g. <prefix>/lib
``SYSTEM_LIBRARY_PATHS``
  Global list of library paths intended to be searched by and find_xxx call
``ILMBASE_USE_STATIC_LIBS``
  Only search for static ilmbase libraries
``DISABLE_CMAKE_SEARCH_PATHS``
  Disable CMakes default search paths for find_xxx calls in this module

#]=======================================================================]

cmake_minimum_required(VERSION 3.12)
include(GNUInstallDirs)

# Monitoring <PackageName>_ROOT variables
if(POLICY CMP0074)
  cmake_policy(SET CMP0074 NEW)
endif()

mark_as_advanced(
  IlmBase_INCLUDE_DIR
  IlmBase_LIBRARY
)

set(_FIND_ILMBASE_ADDITIONAL_OPTIONS "")
if(DISABLE_CMAKE_SEARCH_PATHS)
  set(_FIND_ILMBASE_ADDITIONAL_OPTIONS NO_DEFAULT_PATH)
endif()

set(_ILMBASE_COMPONENT_LIST
  Half
  Iex
  IexMath
  IlmThread
  Imath
)

if(IlmBase_FIND_COMPONENTS)
  set(ILMBASE_COMPONENTS_PROVIDED TRUE)
  set(_IGNORED_COMPONENTS "")
  foreach(COMPONENT ${IlmBase_FIND_COMPONENTS})
    if(NOT ${COMPONENT} IN_LIST _ILMBASE_COMPONENT_LIST)
      list(APPEND _IGNORED_COMPONENTS ${COMPONENT})
    endif()
  endforeach()

  if(_IGNORED_COMPONENTS)
    message(STATUS "Ignoring unknown components of IlmBase:")
    foreach(COMPONENT ${_IGNORED_COMPONENTS})
      message(STATUS "  ${COMPONENT}")
    endforeach()
    list(REMOVE_ITEM IlmBase_FIND_COMPONENTS ${_IGNORED_COMPONENTS})
  endif()
else()
  set(ILMBASE_COMPONENTS_PROVIDED FALSE)
  set(IlmBase_FIND_COMPONENTS ${_ILMBASE_COMPONENT_LIST})
endif()

# Set _ILMBASE_ROOT based on a user provided root var. Xxx_ROOT and ENV{Xxx_ROOT}
# are prioritised over the legacy capitalized XXX_ROOT variables for matching
# CMake 3.12 behaviour
# @todo  deprecate -D and ENV ILMBASE_ROOT from CMake 3.12
if(IlmBase_ROOT)
  set(_ILMBASE_ROOT ${IlmBase_ROOT})
elseif(DEFINED ENV{IlmBase_ROOT})
  set(_ILMBASE_ROOT $ENV{IlmBase_ROOT})
elseif(ILMBASE_ROOT)
  set(_ILMBASE_ROOT ${ILMBASE_ROOT})
elseif(DEFINED ENV{ILMBASE_ROOT})
  set(_ILMBASE_ROOT $ENV{ILMBASE_ROOT})
endif()

# Additionally try and use pkconfig to find IlmBase
if(USE_PKGCONFIG)
  if(NOT DEFINED PKG_CONFIG_FOUND)
    find_package(PkgConfig)
  endif()
  pkg_check_modules(PC_IlmBase QUIET IlmBase)
endif()

# ------------------------------------------------------------------------
#  Search for IlmBase include DIR
# ------------------------------------------------------------------------

set(_ILMBASE_INCLUDE_SEARCH_DIRS "")
list(APPEND _ILMBASE_INCLUDE_SEARCH_DIRS
  ${ILMBASE_INCLUDEDIR}
  ${_ILMBASE_ROOT}
  ${PC_IlmBase_INCLUDEDIR}
  ${SYSTEM_LIBRARY_PATHS}
)

# Look for a standard IlmBase header file.
find_path(IlmBase_INCLUDE_DIR IlmBaseConfig.h
  ${_FIND_ILMBASE_ADDITIONAL_OPTIONS}
  PATHS ${_ILMBASE_INCLUDE_SEARCH_DIRS}
  PATH_SUFFIXES ${CMAKE_INSTALL_INCLUDEDIR}/OpenEXR include/OpenEXR OpenEXR
)

if(EXISTS "${IlmBase_INCLUDE_DIR}/IlmBaseConfig.h")
  # Get the ILMBASE version information from the config header
  file(STRINGS "${IlmBase_INCLUDE_DIR}/IlmBaseConfig.h"
    _ilmbase_version_major_string REGEX "#define ILMBASE_VERSION_MAJOR "
  )
  string(REGEX REPLACE "#define ILMBASE_VERSION_MAJOR" ""
    _ilmbase_version_major_string "${_ilmbase_version_major_string}"
  )
  string(STRIP "${_ilmbase_version_major_string}" IlmBase_VERSION_MAJOR)

  file(STRINGS "${IlmBase_INCLUDE_DIR}/IlmBaseConfig.h"
     _ilmbase_version_minor_string REGEX "#define ILMBASE_VERSION_MINOR "
  )
  string(REGEX REPLACE "#define ILMBASE_VERSION_MINOR" ""
    _ilmbase_version_minor_string "${_ilmbase_version_minor_string}"
  )
  string(STRIP "${_ilmbase_version_minor_string}" IlmBase_VERSION_MINOR)

  unset(_ilmbase_version_major_string)
  unset(_ilmbase_version_minor_string)

  set(IlmBase_VERSION ${IlmBase_VERSION_MAJOR}.${IlmBase_VERSION_MINOR})
endif()

# ------------------------------------------------------------------------
#  Search for ILMBASE lib DIR
# ------------------------------------------------------------------------

set(_ILMBASE_LIBRARYDIR_SEARCH_DIRS "")

# Append to _ILMBASE_LIBRARYDIR_SEARCH_DIRS in priority order

list(APPEND _ILMBASE_LIBRARYDIR_SEARCH_DIRS
  ${ILMBASE_LIBRARYDIR}
  ${_ILMBASE_ROOT}
  ${PC_IlmBase_LIBDIR}
  ${SYSTEM_LIBRARY_PATHS}
)

# Library suffix handling

set(_ILMBASE_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})
set(_IlmBase_Version_Suffix "-${IlmBase_VERSION_MAJOR}_${IlmBase_VERSION_MINOR}")

if(WIN32)
  if(ILMBASE_USE_STATIC_LIBS)
    set(CMAKE_FIND_LIBRARY_SUFFIXES ".lib")
  endif()
  list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES "${_IlmBase_Version_Suffix}.lib")
else()
  if(ILMBASE_USE_STATIC_LIBS)
    set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
  else()
    if(APPLE)
      list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES "${_IlmBase_Version_Suffix}.dylib")
    else()
      list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES "${_IlmBase_Version_Suffix}.so")
    endif()
  endif()
  list(APPEND CMAKE_FIND_LIBRARY_SUFFIXES "${_IlmBase_Version_Suffix}.a")
endif()

unset(_IlmBase_Version_Suffix)

set(IlmBase_LIB_COMPONENTS "")

foreach(COMPONENT ${IlmBase_FIND_COMPONENTS})
  find_library(IlmBase_${COMPONENT}_LIBRARY ${COMPONENT}
    ${_FIND_ILMBASE_ADDITIONAL_OPTIONS}
    PATHS ${_ILMBASE_LIBRARYDIR_SEARCH_DIRS}
    PATH_SUFFIXES ${CMAKE_INSTALL_LIBDIR} lib64 lib
  )
  list(APPEND IlmBase_LIB_COMPONENTS ${IlmBase_${COMPONENT}_LIBRARY})

  if(IlmBase_${COMPONENT}_LIBRARY)
    set(IlmBase_${COMPONENT}_FOUND TRUE)
  else()
    set(IlmBase_${COMPONENT}_FOUND FALSE)
  endif()
endforeach()

# Reset library suffix

set(CMAKE_FIND_LIBRARY_SUFFIXES ${_ILMBASE_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES})
unset(_ILMBASE_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES)

# ------------------------------------------------------------------------
#  Cache and set ILMBASE_FOUND
# ------------------------------------------------------------------------

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(IlmBase
  FOUND_VAR IlmBase_FOUND
  REQUIRED_VARS
    IlmBase_INCLUDE_DIR
    IlmBase_LIB_COMPONENTS
  VERSION_VAR IlmBase_VERSION
  HANDLE_COMPONENTS
)

if(IlmBase_FOUND)
  set(IlmBase_LIBRARIES ${IlmBase_LIB_COMPONENTS})

  # We have to add both include and include/OpenEXR to the include
  # path in case OpenEXR and IlmBase are installed separately.
  #
  # Make sure we get the absolute path to avoid issues where
  # /usr/include/OpenEXR/../ is picked up and passed to gcc from cmake
  # which won't correctly compute /usr/include as an implicit system
  # dir if the path is relative:
  #
  # https://github.com/AcademySoftwareFoundation/openvdb/issues/632
  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70129

  set(_IlmBase_Parent_Dir "")
  get_filename_component(_IlmBase_Parent_Dir
    ${IlmBase_INCLUDE_DIR}/../ ABSOLUTE)

  set(IlmBase_INCLUDE_DIRS)
  list(APPEND IlmBase_INCLUDE_DIRS
    ${_IlmBase_Parent_Dir}
    ${IlmBase_INCLUDE_DIR}
  )
  unset(_IlmBase_Parent_Dir)

  set(IlmBase_LIBRARY_DIRS "")
  foreach(LIB ${IlmBase_LIB_COMPONENTS})
    get_filename_component(_ILMBASE_LIBDIR ${LIB} DIRECTORY)
    list(APPEND IlmBase_LIBRARY_DIRS ${_ILMBASE_LIBDIR})
  endforeach()
  list(REMOVE_DUPLICATES IlmBase_LIBRARY_DIRS)

  # Configure imported targets

  foreach(COMPONENT ${IlmBase_FIND_COMPONENTS})
    # Configure lib type. If XXX_USE_STATIC_LIBS, we always assume a static
    # lib is in use. If win32, we can't mark the import .libs as shared, so
    # these are always marked as UNKNOWN. Otherwise, infer from extension.
    set(ILMBASE_${COMPONENT}_LIB_TYPE UNKNOWN)
    if(ILMBASE_USE_STATIC_LIBS)
      set(ILMBASE_${COMPONENT}_LIB_TYPE STATIC)
    elseif(UNIX)
      get_filename_component(_ILMBASE_${COMPONENT}_EXT ${IlmBase_${COMPONENT}_LIBRARY} EXT)
      if(${_ILMBASE_${COMPONENT}_EXT} STREQUAL ".a")
        set(ILMBASE_${COMPONENT}_LIB_TYPE STATIC)
      elseif(${_ILMBASE_${COMPONENT}_EXT} STREQUAL ".so" OR
             ${_ILMBASE_${COMPONENT}_EXT} STREQUAL ".dylib")
        set(ILMBASE_${COMPONENT}_LIB_TYPE SHARED)
      endif()
    endif()

    set(IlmBase_${COMPONENT}_DEFINITIONS)

    # Add the OPENEXR_DLL define if the library is not static on WIN32
    if(WIN32)
      if(NOT ILMBASE_${COMPONENT}_LIB_TYPE STREQUAL STATIC)
        list(APPEND IlmBase_${COMPONENT}_DEFINITIONS OPENEXR_DLL)
      endif()
    endif()

    if(NOT TARGET IlmBase::${COMPONENT})
      add_library(IlmBase::${COMPONENT} ${ILMBASE_${COMPONENT}_LIB_TYPE} IMPORTED)
      set_target_properties(IlmBase::${COMPONENT} PROPERTIES
        IMPORTED_LOCATION "${IlmBase_${COMPONENT}_LIBRARY}"
        INTERFACE_COMPILE_OPTIONS "${PC_IlmBase_CFLAGS_OTHER}"
        INTERFACE_COMPILE_DEFINITIONS "${IlmBase_${COMPONENT}_DEFINITIONS}"
        INTERFACE_INCLUDE_DIRECTORIES "${IlmBase_INCLUDE_DIRS}"
      )
    endif()
  endforeach()

elseif(IlmBase_FIND_REQUIRED)
  message(FATAL_ERROR "Unable to find IlmBase")
endif()