# FindTorch
# -------
#
# Finds the Torch library
#
# This will define the following variables:
#
#   TORCH_FOUND        -- True if the system has the Torch library
#   TORCH_INCLUDE_DIRS -- The include directories for torch
#   TORCH_LIBRARIES    -- Libraries to link against
#   TORCH_CXX_FLAGS    -- Additional (required) compiler flags
#
# and the following imported targets:
#
#   torch

include(FindPackageHandleStandardArgs)

if(DEFINED ENV{TORCH_INSTALL_PREFIX})
  set(TORCH_INSTALL_PREFIX $ENV{TORCH_INSTALL_PREFIX})
else()
  # Assume we are in <install-prefix>/share/cmake/Torch/TorchConfig.cmake
  get_filename_component(CMAKE_CURRENT_LIST_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
  get_filename_component(TORCH_INSTALL_PREFIX "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)
endif()

# Include directories.
if(EXISTS "${TORCH_INSTALL_PREFIX}/include")
  set(TORCH_INCLUDE_DIRS
    ${TORCH_INSTALL_PREFIX}/include
    ${TORCH_INSTALL_PREFIX}/include/torch/csrc/api/include)
else()
  set(TORCH_INCLUDE_DIRS
    ${TORCH_INSTALL_PREFIX}/include
    ${TORCH_INSTALL_PREFIX}/include/torch/csrc/api/include)
endif()

# Library dependencies.
if(ON)
  find_package(Caffe2 REQUIRED PATHS ${CMAKE_CURRENT_LIST_DIR}/../Caffe2)
  set(TORCH_LIBRARIES torch ${Caffe2_MAIN_LIBS})
else()
  add_library(torch STATIC IMPORTED) # set imported_location at the bottom
  set(TORCH_LIBRARIES torch)
endif()

find_library(C10_LIBRARY c10 PATHS "${TORCH_INSTALL_PREFIX}/lib")
list(APPEND TORCH_LIBRARIES ${C10_LIBRARY})

# We need manually add dependent libraries when they are not linked into the
# shared library.
# TODO: this list might be incomplete.
if(NOT ON)
  find_library(TORCH_CPU_LIBRARY torch_cpu PATHS "${TORCH_INSTALL_PREFIX}/lib")
  list(APPEND TORCH_LIBRARIES ${TORCH_CPU_LIBRARY})

  if(ON)
    find_library(NNPACK_LIBRARY nnpack PATHS "${TORCH_INSTALL_PREFIX}/lib")
    list(APPEND TORCH_LIBRARIES ${NNPACK_LIBRARY})
  endif()

  if(ON)
    find_library(PYTORCH_QNNPACK_LIBRARY pytorch_qnnpack PATHS "${TORCH_INSTALL_PREFIX}/lib")
    list(APPEND TORCH_LIBRARIES ${PYTORCH_QNNPACK_LIBRARY})
  endif()

  if(ON)
    find_library(XNNPACK_LIBRARY XNNPACK PATHS "${TORCH_INSTALL_PREFIX}/lib")
    list(APPEND TORCH_LIBRARIES ${XNNPACK_LIBRARY})
  endif()

  if()
    find_library(EIGEN_BLAS_LIBRARY eigen_blas PATHS "${TORCH_INSTALL_PREFIX}/lib")
    list(APPEND TORCH_LIBRARIES ${EIGEN_BLAS_LIBRARY})
  endif()

  find_library(CPUINFO_LIBRARY cpuinfo PATHS "${TORCH_INSTALL_PREFIX}/lib")
  list(APPEND TORCH_LIBRARIES ${CPUINFO_LIBRARY})

  find_library(CLOG_LIBRARY clog PATHS "${TORCH_INSTALL_PREFIX}/lib")
  list(APPEND TORCH_LIBRARIES ${CLOG_LIBRARY})
endif()

if(0)
  if(MSVC)
    set(NVTOOLEXT_HOME "C:/Program Files/NVIDIA Corporation/NvToolsExt")
    if($ENV{NVTOOLEXT_HOME})
      set(NVTOOLEXT_HOME $ENV{NVTOOLEXT_HOME})
    endif()
    set(TORCH_CUDA_LIBRARIES
      ${NVTOOLEXT_HOME}/lib/x64/nvToolsExt64_1.lib
      ${CUDA_LIBRARIES})
    list(APPEND TORCH_INCLUDE_DIRS ${NVTOOLEXT_HOME}/include)
    find_library(CAFFE2_NVRTC_LIBRARY caffe2_nvrtc PATHS "${TORCH_INSTALL_PREFIX}/lib")
    list(APPEND TORCH_CUDA_LIBRARIES ${CAFFE2_NVRTC_LIBRARY})
  elseif(APPLE)
    set(TORCH_CUDA_LIBRARIES
      ${CUDA_TOOLKIT_ROOT_DIR}/lib/libcudart.dylib
      ${CUDA_TOOLKIT_ROOT_DIR}/lib/libnvrtc.dylib
      ${CUDA_TOOLKIT_ROOT_DIR}/lib/libnvToolsExt.dylib
      ${CUDA_LIBRARIES})
  else()
    find_library(LIBNVTOOLSEXT libnvToolsExt.so PATHS ${CUDA_TOOLKIT_ROOT_DIR}/lib64/)
    set(TORCH_CUDA_LIBRARIES
      ${CUDA_CUDA_LIB}
      ${CUDA_NVRTC_LIB}
      ${LIBNVTOOLSEXT}
      ${CUDA_LIBRARIES})
  endif()
  find_library(C10_CUDA_LIBRARY c10_cuda PATHS "${TORCH_INSTALL_PREFIX}/lib")
  list(APPEND TORCH_CUDA_LIBRARIES ${C10_CUDA_LIBRARY})
  list(APPEND TORCH_LIBRARIES ${TORCH_CUDA_LIBRARIES})
endif()

# When we build libtorch with the old GCC ABI, dependent libraries must too.
if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
  set(TORCH_CXX_FLAGS "-D_GLIBCXX_USE_CXX11_ABI=0")
endif()

find_library(TORCH_LIBRARY torch PATHS "${TORCH_INSTALL_PREFIX}/lib")
set_target_properties(torch PROPERTIES
    IMPORTED_LOCATION "${TORCH_LIBRARY}"
    INTERFACE_INCLUDE_DIRECTORIES "${TORCH_INCLUDE_DIRS}"
    CXX_STANDARD 14
)
if(TORCH_CXX_FLAGS)
  set_property(TARGET torch PROPERTY INTERFACE_COMPILE_OPTIONS "${TORCH_CXX_FLAGS}")
endif()

find_package_handle_standard_args(Torch DEFAULT_MSG TORCH_LIBRARY TORCH_INCLUDE_DIRS)
