if(NOT DEFINED CPPBESSOT_TARGET_FILE OR "${CPPBESSOT_TARGET_FILE}" STREQUAL "")
  message(FATAL_ERROR "CPPBESSOT_TARGET_FILE is required")
endif()

# Some CMake command invocations can pass wrapped quotes through -D values.
set(_target_file "${CPPBESSOT_TARGET_FILE}")
string(REGEX REPLACE "^\"(.*)\"$" "\\1" _target_file "${_target_file}")

if(NOT EXISTS "${_target_file}")
  message(FATAL_ERROR "Target file does not exist: ${_target_file}")
endif()

file(READ "${_target_file}" _content)

if(_content MATCHES "AUTO-GENERATED BY CppBeSsot")
  return()
endif()

set(_notice "/*\n * AUTO-GENERATED BY CppBeSsot.\n * Direct edits are pointless: this file is regenerated.\n * Update the OpenAPI schema and/or CppBeSsot templates, then regenerate generated-* outputs.\n */\n\n")
file(WRITE "${_target_file}" "${_notice}${_content}")