#
# Copyright by The HDF Group.
# All rights reserved.
#
# This file is part of HDF5.  The full HDF5 copyright notice, including
# terms governing use, modification, and redistribution, is contained in
# the LICENSE file, which can be found at the root of the source code
# distribution tree, or in https://www.hdfgroup.org/licenses.
# If you do not have access to either file, you may request a copy from
# help@hdfgroup.org.
#

# -----------------------------------------------------------------------------
# HDF5 CMake Filter Plugin Support Configuration
# -----------------------------------------------------------------------------
# This CMake module configures support for external filter plugins in HDF5.
# It provides options for enabling/disabling plugin support, selecting
# static/shared builds, and controlling how plugin dependencies are found or
# built (external, local, or via GIT/TGZ).
#
# Key Features:
# - Options to enable/disable plugin support and select external or local builds.
# - Support for building plugins externally (via GIT or TGZ) or using system libraries.
# - Handles configuration of plugin include directories, library targets, and CMake variables.
# - Sets up required variables for HDF5 to use filter plugins.
#
# Usage:
#   HDF5 includes this file from the main CMakeLists.txt if filter plugin support
#   in HDF5 is enabled (HDF5_ENABLE_PLUGIN_SUPPORT). Configure options as needed before
#   including this file.
#
# See comments throughout for details on each option and logic branch.
# -----------------------------------------------------------------------------

option (PLUGIN_USE_EXTERNAL "Use External Library Building for filter PLUGIN else search" OFF)
cmake_dependent_option (PLUGIN_USE_LOCALCONTENT "Use local file for PLUGIN FetchContent" OFF PLUGIN_USE_EXTERNAL OFF)

include (ExternalProject)

# -----------------------------------------------------------------------------
# Option for enabling filter plugin support by building the plugins from external sources
# -----------------------------------------------------------------------------
#option (HDF5_ALLOW_EXTERNAL_SUPPORT "Allow External Library Building (NO GIT TGZ)" "NO")
set (HDF5_ALLOW_EXTERNAL_SUPPORT "NO" CACHE STRING "Allow External Library Building (NO GIT TGZ)")
set_property (CACHE HDF5_ALLOW_EXTERNAL_SUPPORT PROPERTY STRINGS NO GIT TGZ)
if (HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "GIT" OR HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "TGZ")
  set (PLUGIN_USE_EXTERNAL ON CACHE BOOL "Use External Library Building for PLUGIN else search" FORCE)
  if (HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "GIT")
    set (PLUGIN_URL ${PLUGIN_GIT_URL} CACHE STRING "Path to PLUGIN git repository")
    set (PLUGIN_BRANCH ${PLUGIN_GIT_BRANCH})
  elseif (HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "TGZ")
    if (NOT H5PL_TGZPATH)
      set (H5PL_TGZPATH ${TGZPATH})
    endif ()
    if (NOT PLUGIN_USE_LOCALCONTENT)
      set (PLUGIN_URL ${PLUGIN_TGZ_ORIGPATH}/${PLUGIN_TGZ_NAME})
    else ()
      if (NOT H5PL_TGZPATH)
        set (H5PL_TGZPATH ${TGZPATH})
      endif ()
      set (PLUGIN_URL ${H5PL_TGZPATH}/${PLUGIN_TGZ_NAME})
      if (NOT EXISTS "${PLUGIN_URL}")
        set (HDF5_ENABLE_PLUGIN_SUPPORT OFF CACHE BOOL "" FORCE)
        message (VERBOSE "Filter PLUGIN file ${PLUGIN_URL} not found")
      endif ()
    endif ()
    message (VERBOSE "Filter PLUGIN file is ${PLUGIN_URL}")
  else ()
    set (PLUGIN_USE_EXTERNAL OFF CACHE BOOL "Use External Library Building for PLUGIN else search")
    message (VERBOSE "Filter PLUGIN not built")
  endif ()
endif ()

#-----------------------------------------------------------------------------
# Option for PLUGIN support
#-----------------------------------------------------------------------------
if (HDF5_ENABLE_PLUGIN_SUPPORT)
  if (NOT PLUGIN_USE_EXTERNAL) # This checks if plugins should be found on the system or built from an external source
    find_package (PLUGIN NAMES ${PLUGIN_PACKAGE_NAME}${HDF_PACKAGE_EXT})
    if (NOT PLUGIN_FOUND)
      find_package (PLUGIN) # Legacy find
    endif ()
  else ()
    if (HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "GIT" OR HDF5_ALLOW_EXTERNAL_SUPPORT MATCHES "TGZ")
      EXTERNAL_PLUGIN_LIBRARY (${HDF5_ALLOW_EXTERNAL_SUPPORT})
      message (STATUS "Filter PLUGIN is built")
    endif ()
  endif ()
  if (PLUGIN_FOUND)
    message (STATUS "Filter PLUGIN is ON")
  else ()
    set (HDF5_ENABLE_PLUGIN_SUPPORT OFF CACHE BOOL "" FORCE)
    message (FATAL_ERROR " PLUGIN support in HDF5 was enabled but not found")
  endif ()
endif ()