# Match the minimum required version of onnx-mlir
cmake_minimum_required(VERSION 3.20.0)

project(raptor)

# Materialize a CMake shim directory
function(raptor_write_external_cmake_shim shim_dir external_source_dir description)
  get_filename_component(real_external_source_dir "${external_source_dir}" REALPATH)
  file(RELATIVE_PATH relative_external_source_dir "${shim_dir}" "${real_external_source_dir}")

  if (NOT EXISTS "${real_external_source_dir}/CMakeLists.txt")
    message(FATAL_ERROR
      "External CMake source directory not found or missing CMakeLists.txt:\n"
      "  ${real_external_source_dir}"
    )
  endif ()

  if (IS_SYMLINK "${shim_dir}")
    message(STATUS "Removing old full-directory symlink: ${shim_dir}")
    file(REMOVE "${shim_dir}")
  endif ()

  if (EXISTS "${shim_dir}" AND NOT IS_DIRECTORY "${shim_dir}")
    message(FATAL_ERROR "Expected directory or absent path, got file: ${shim_dir}")
  endif ()

  file(MAKE_DIRECTORY "${shim_dir}")

  set(shim_file "${shim_dir}/CMakeLists.txt")
  set(shim_contents
    "get_filename_component(raptor_external_source_dir
    \"\${CMAKE_CURRENT_LIST_DIR}/${relative_external_source_dir}\"
    REALPATH
)
add_subdirectory(
    \"\${raptor_external_source_dir}\"
    \"\${CMAKE_CURRENT_BINARY_DIR}/raptor-external\"
)
if (DEFINED PIM_ENABLED)
    set(PIM_ENABLED \"\${PIM_ENABLED}\" PARENT_SCOPE)
endif ()
"
  )

  if (EXISTS "${shim_file}")
    file(READ "${shim_file}" old_contents)
  else ()
    set(old_contents "")
  endif ()

  if (NOT old_contents STREQUAL shim_contents)
    file(WRITE "${shim_file}" "${shim_contents}")
    message(STATUS "Wrote CMake shim for ${description}: ${shim_file}")
  else ()
    message(STATUS "CMake shim already up to date for ${description}")
  endif ()

  # Mirror the external tree's first-level entries into the shim directory
  # so legacy includes like src/Accelerators/PIM/Compiler/... keep working.
  file(GLOB children RELATIVE "${real_external_source_dir}" "${real_external_source_dir}/*")

  foreach (child IN LISTS children)
    if (child STREQUAL "CMakeLists.txt")
      continue()
    endif ()

    set(real_child "${real_external_source_dir}/${child}")
    set(shim_child "${shim_dir}/${child}")

    if (IS_SYMLINK "${shim_child}")
      file(READ_SYMLINK "${shim_child}" existing_link_target)
      if (existing_link_target STREQUAL real_child)
        continue()
      endif ()
      file(REMOVE_RECURSE "${shim_child}")
    elseif (EXISTS "${shim_child}")
      # Do not delete real files/directories. This protects the generated shim.
      continue()
    endif ()

    file(CREATE_LINK
      "${real_child}"
      "${shim_child}"
      SYMBOLIC
    )
  endforeach ()
endfunction()

raptor_write_external_cmake_shim(
  "${CMAKE_CURRENT_SOURCE_DIR}/onnx-mlir/src/Accelerators/PIM"
  "${CMAKE_CURRENT_SOURCE_DIR}/src/PIM"
  "PIM accelerator"
)

raptor_write_external_cmake_shim(
  "${CMAKE_CURRENT_SOURCE_DIR}/onnx-mlir/test/accelerators/PIM"
  "${CMAKE_CURRENT_SOURCE_DIR}/test/PIM"
  "PIM accelerator tests"
)

# Patch onnx-mlir sources for PIM accelerator support.
# Each patch searches for a context-aware anchor string rather than relying on
# line numbers, so that moderate upstream changes are tolerated.
function(raptor_apply_patch file_path anchor replacement description)
  file(READ "${file_path}" contents)

  # Already applied – replacement text is present
  string(FIND "${contents}" "${replacement}" already_applied_pos)
  if (NOT already_applied_pos EQUAL -1)
    message(STATUS "Patch already applied: ${description}")
    return()
  endif ()

  # Anchor must exist for the patch to be applicable
  string(FIND "${contents}" "${anchor}" anchor_pos)
  if (anchor_pos EQUAL -1)
    message(FATAL_ERROR
      "Patch anchor not found – onnx-mlir may have changed.\n"
      "  Patch : ${description}\n"
      "  File  : ${file_path}\n"
      "  Anchor: ${anchor}"
    )
  endif ()

  string(REPLACE "${anchor}" "${replacement}" patched "${contents}")
  file(WRITE "${file_path}" "${patched}")
  message(STATUS "Patch applied: ${description}")
endfunction()

set(ONNX_MLIR_DIR "${CMAKE_CURRENT_SOURCE_DIR}/onnx-mlir")

# Register PIM compiler options alongside NNPA
raptor_apply_patch(
  "${ONNX_MLIR_DIR}/src/Accelerators/Accelerator.hpp"
  "#include \"src/Accelerators/NNPA/Compiler/NNPACompilerOptions.hpp\""
  "#include \"src/Accelerators/NNPA/Compiler/NNPACompilerOptions.hpp\"\n#include \"src/Accelerators/PIM/Compiler/PimCompilerOptions.hpp\""
  "Add PIM compiler options include"
)

# Short-circuit output emission for the PIM accelerator
raptor_apply_patch(
  "${ONNX_MLIR_DIR}/src/Compiler/CompilerUtils.cpp"
  "switch (emissionTarget) {\n  case EmitObj: {"
  "if (llvm::is_contained(maccel, accel::Accelerator::Kind::PIM))\n    return CompilerSuccess;\n  switch (emissionTarget) {\n  case EmitObj: {"
  "Skip output emission for PIM accelerator"
)

add_subdirectory(onnx-mlir)