#=============================================================================
# Copyright (c) 2024, NVIDIA CORPORATION.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#=============================================================================
include_guard(GLOBAL)

function(check_copyright_header file)
  cmake_path(GET file EXTENSION LAST_ONLY file_ext)
  string(TIMESTAMP current_year "%Y" UTC)
  if(file_ext STREQUAL ".txt" OR file_ext STREQUAL ".cmake")
    string(CONFIGURE [=[#=============================================================================
# Copyright (c) @current_year@, NVIDIA CORPORATION.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#=============================================================================
]=] expected_header @ONLY)
  else()
    string(CONFIGURE [=[/*
 * Copyright (c) @current_year@, NVIDIA CORPORATION.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
]=] expected_header @ONLY)
  endif()
  string(LENGTH "${expected_header}" expected_header_length)

  file(READ "${file}" actual_header LIMIT "${expected_header_length}")
  if(NOT actual_header STREQUAL expected_header)
    message(FATAL_ERROR "File ${file} did not have expected copyright header")
  endif()
endfunction()