include(CMakeParseArguments)
include(FetchContent)

# Resolve hdk-assets for examples only.
function(hdk_resolve_example_assets)
  set(_opts "")
  set(_one_value OUT_VAR FETCH_OPTION MIN_VERSION GIT_REPOSITORY GIT_TAG CONTEXT)
  cmake_parse_arguments(HDK_ASSETS "${_opts}" "${_one_value}" "" ${ARGN})

  if(NOT HDK_ASSETS_OUT_VAR)
    message(FATAL_ERROR "hdk_resolve_example_assets requires OUT_VAR")
  endif()

  set(_resolved_assets_dir "")
  set(_repo_assets_dir "${CMAKE_CURRENT_SOURCE_DIR}/../../assets")
  if(EXISTS "${_repo_assets_dir}/textures")
    set(_resolved_assets_dir "${_repo_assets_dir}")
  endif()

  if(NOT _resolved_assets_dir)
    if(HDK_ASSETS_MIN_VERSION)
      find_package(hdk_assets ${HDK_ASSETS_MIN_VERSION} QUIET CONFIG NAMES hdk-assets hdk_assets)
    else()
      find_package(hdk_assets QUIET CONFIG NAMES hdk-assets hdk_assets)
    endif()

    foreach(_candidate_var IN ITEMS HDK_ASSETS_SOURCE_DIR HDK_ASSETS_DIR hdk_assets_SOURCE_DIR hdk_assets_DIR)
      if(NOT _resolved_assets_dir AND DEFINED ${_candidate_var})
        set(_candidate_dir "${${_candidate_var}}")
        if(EXISTS "${_candidate_dir}/textures")
          set(_resolved_assets_dir "${_candidate_dir}")
        endif()
      endif()
    endforeach()

    if(NOT _resolved_assets_dir AND DEFINED hdk_assets_DIR)
      get_filename_component(_hdk_assets_prefix "${hdk_assets_DIR}" DIRECTORY)
      get_filename_component(_hdk_assets_prefix "${_hdk_assets_prefix}" DIRECTORY)
      get_filename_component(_hdk_assets_prefix "${_hdk_assets_prefix}" DIRECTORY)
      if(EXISTS "${_hdk_assets_prefix}/assets/textures")
        set(_resolved_assets_dir "${_hdk_assets_prefix}/assets")
      endif()
    endif()
  endif()

  if(NOT _resolved_assets_dir)
    if(NOT HDK_ASSETS_FETCH_OPTION)
      if(HDK_ASSETS_CONTEXT)
        message(FATAL_ERROR "No suitable hdk-assets source found for ${HDK_ASSETS_CONTEXT} and fetch fallback is disabled")
      else()
        message(FATAL_ERROR "No suitable hdk-assets source found and fetch fallback is disabled")
      endif()
    endif()

    if(NOT HDK_ASSETS_GIT_REPOSITORY)
      message(FATAL_ERROR "hdk_resolve_example_assets fallback requires GIT_REPOSITORY")
    endif()
    if(NOT HDK_ASSETS_GIT_TAG)
      message(FATAL_ERROR "hdk_resolve_example_assets fallback requires GIT_TAG")
    endif()

    FetchContent_Declare(
      hdk_assets
      GIT_REPOSITORY ${HDK_ASSETS_GIT_REPOSITORY}
      GIT_TAG ${HDK_ASSETS_GIT_TAG}
    )
    FetchContent_MakeAvailable(hdk_assets)
    set(_resolved_assets_dir "${hdk_assets_SOURCE_DIR}")
  endif()

  set(${HDK_ASSETS_OUT_VAR} "${_resolved_assets_dir}" PARENT_SCOPE)
endfunction()