include_guard(GLOBAL)

if(NOT DEFINED CPPBESSOT_WORKDIR)
  set(CPPBESSOT_WORKDIR "db" CACHE STRING "CppBeSSOT schema root folder, relative to PROJECT_SOURCE_DIR or absolute path")
endif()

set(_CPPBESSOT_GENERATION_COMMON_DIR "${CMAKE_CURRENT_LIST_DIR}")

function(cppbessot_abs_path out_var input_path)
  # Purpose: Resolve a path to an absolute path anchored at PROJECT_SOURCE_DIR
  #          when the input is relative.
  # Inputs:
  #   - out_var: Name of the parent-scope variable to write.
  #   - input_path: Relative or absolute input path.
  # Outputs:
  #   - <out_var> (PARENT_SCOPE): Absolute resolved path.
  if(IS_ABSOLUTE "${input_path}")
    set(_resolved "${input_path}")
  else()
    set(_resolved "${PROJECT_SOURCE_DIR}/${input_path}")
  endif()

  get_filename_component(_resolved "${_resolved}" ABSOLUTE)
  set(${out_var} "${_resolved}" PARENT_SCOPE)
endfunction()

function(cppbessot_initialize_paths)
  # Purpose: Initialize commonly used CppBeSSOT module and workdir paths.
  # Inputs:
  #   - CPPBESSOT_WORKDIR (cache/normal variable): Configured schema root path.
  # Outputs:
  #   - CPPBESSOT_CMAKE_DIR (PARENT_SCOPE): Absolute module directory path.
  #   - CPPBESSOT_MODULE_ROOT (PARENT_SCOPE): Module root directory path.
  #   - CPPBESSOT_WORKDIR_ABS (PARENT_SCOPE): Absolute schema root path.
  get_filename_component(CPPBESSOT_CMAKE_DIR "${_CPPBESSOT_GENERATION_COMMON_DIR}" ABSOLUTE)
  get_filename_component(CPPBESSOT_MODULE_ROOT "${CPPBESSOT_CMAKE_DIR}/.." ABSOLUTE)
  cppbessot_abs_path(CPPBESSOT_WORKDIR_ABS "${CPPBESSOT_WORKDIR}")

  set(CPPBESSOT_CMAKE_DIR "${CPPBESSOT_CMAKE_DIR}" PARENT_SCOPE)
  set(CPPBESSOT_MODULE_ROOT "${CPPBESSOT_MODULE_ROOT}" PARENT_SCOPE)
  set(CPPBESSOT_WORKDIR_ABS "${CPPBESSOT_WORKDIR_ABS}" PARENT_SCOPE)
endfunction()

function(cppbessot_require_var var_name)
  # Purpose: Fail fast if a required CMake variable is missing/empty.
  # Inputs:
  #   - var_name: Variable name to validate.
  # Outputs:
  #   - No return value; raises FATAL_ERROR on invalid input.
  if(NOT DEFINED ${var_name} OR "${${var_name}}" STREQUAL "")
    message(FATAL_ERROR "Missing required CMake variable `${var_name}`.")
  endif()
endfunction()

function(cppbessot_validate_schema_dir_name schema_dir)
  # Purpose: Validate that a schema directory selector is a basename, not a path.
  # Inputs:
  #   - schema_dir: Directory basename under CPPBESSOT_WORKDIR.
  # Outputs:
  #   - No return value; raises FATAL_ERROR if format is invalid.
  if("${schema_dir}" STREQUAL "")
    message(FATAL_ERROR "Schema directory name must not be empty.")
  endif()

  if("${schema_dir}" MATCHES "[/\\\\]")
    message(FATAL_ERROR
      "Schema directory name `${schema_dir}` must be a basename under CPPBESSOT_WORKDIR, not a path.")
  endif()
endfunction()

function(cppbessot_get_schema_dir_path out_var schema_dir)
  # Purpose: Resolve the absolute folder path for a specific schema directory.
  # Inputs:
  #   - out_var: Parent-scope variable name to receive the path.
  #   - schema_dir: Schema directory basename under CPPBESSOT_WORKDIR.
  # Outputs:
  #   - <out_var> (PARENT_SCOPE): Absolute `${CPPBESSOT_WORKDIR}/<schema_dir>` path.
  cppbessot_validate_schema_dir_name("${schema_dir}")
  cppbessot_abs_path(_workdir "${CPPBESSOT_WORKDIR}")
  set(${out_var} "${_workdir}/${schema_dir}" PARENT_SCOPE)
endfunction()

function(cppbessot_assert_schema_dir_exists schema_dir)
  # Purpose: Assert that a schema directory exists on disk.
  # Inputs:
  #   - schema_dir: Schema directory basename.
  # Outputs:
  #   - No return value; raises FATAL_ERROR if directory is missing.
  cppbessot_get_schema_dir_path(_schema_dir_path "${schema_dir}")
  if(NOT IS_DIRECTORY "${_schema_dir_path}")
    message(FATAL_ERROR "Schema directory does not exist: ${_schema_dir_path}")
  endif()
endfunction()

function(cppbessot_get_model_headers_glob out_var schema_dir)
  # Purpose: Build a model-header glob expression for a schema directory.
  # Inputs:
  #   - out_var: Parent-scope variable name to receive the glob pattern.
  #   - schema_dir: Schema directory basename.
  # Outputs:
  #   - <out_var> (PARENT_SCOPE): Glob pattern for generated model headers.
  cppbessot_get_schema_dir_path(_schema_dir_path "${schema_dir}")
  set(${out_var} "${_schema_dir_path}/generated-cpp-source/include/*/model/*.h" PARENT_SCOPE)
endfunction()

function(cppbessot_get_openapi_schema_names out_var schema_dir)
  # Purpose: Parse top-level component schema names from a schema directory's OpenAPI file.
  # Inputs:
  #   - out_var: Parent-scope variable name to receive the schema names.
  #   - schema_dir: Schema directory basename.
  # Outputs:
  #   - <out_var> (PARENT_SCOPE): List of top-level component schema names.
  cppbessot_get_schema_dir_path(_schema_dir_path "${schema_dir}")
  set(_openapi_file "${_schema_dir_path}/openapi/openapi.yaml")
  if(NOT EXISTS "${_openapi_file}")
    message(FATAL_ERROR "OpenAPI file does not exist: ${_openapi_file}")
  endif()

  file(STRINGS "${_openapi_file}" _openapi_lines)
  set(_schema_names)
  set(_in_components FALSE)
  set(_in_schemas FALSE)

  foreach(_line IN LISTS _openapi_lines)
    if(_in_schemas)
      if(_line MATCHES "^[^ ]" OR _line MATCHES "^  [^ ]")
        set(_in_schemas FALSE)
      elseif(_line MATCHES "^    ([A-Za-z_][A-Za-z0-9_]*)[ \t]*:[ \t]*$")
        list(APPEND _schema_names "${CMAKE_MATCH_1}")
      endif()
    endif()

    if(_in_components AND NOT _in_schemas)
      if(_line MATCHES "^[^ ]")
        set(_in_components FALSE)
      elseif(_line MATCHES "^  schemas:[ \t]*$")
        set(_in_schemas TRUE)
      endif()
    endif()

    if(_line MATCHES "^components:[ \t]*$")
      set(_in_components TRUE)
    endif()
  endforeach()

  if(NOT _schema_names)
    message(FATAL_ERROR
      "No component schema names were found in ${_openapi_file}.")
  endif()

  set(${out_var} "${_schema_names}" PARENT_SCOPE)
endfunction()

function(cppbessot_get_expected_cpp_model_outputs out_headers_var out_sources_var schema_dir)
  # Purpose: Infer generated C++ model headers and sources from OpenAPI schema names.
  # Inputs:
  #   - out_headers_var: Parent-scope variable name to receive expected headers.
  #   - out_sources_var: Parent-scope variable name to receive expected sources.
  #   - schema_dir: Schema directory basename.
  # Outputs:
  #   - <out_headers_var> (PARENT_SCOPE): Expected generated model headers.
  #   - <out_sources_var> (PARENT_SCOPE): Expected generated model sources.
  cppbessot_get_schema_dir_path(_schema_dir_path "${schema_dir}")
  cppbessot_get_openapi_schema_names(_schema_names "${schema_dir}")

  set(_headers)
  set(_sources)
  foreach(_schema_name IN LISTS _schema_names)
    list(APPEND _headers
      "${_schema_dir_path}/generated-cpp-source/include/cppbessot/model/${_schema_name}.h")
    list(APPEND _sources
      "${_schema_dir_path}/generated-cpp-source/src/model/${_schema_name}.cpp")
  endforeach()

  set(${out_headers_var} "${_headers}" PARENT_SCOPE)
  set(${out_sources_var} "${_sources}" PARENT_SCOPE)
endfunction()

function(cppbessot_get_expected_odb_outputs out_sqlite_sources_var out_pgsql_sources_var schema_dir)
  # Purpose: Infer generated ODB backend source files from OpenAPI schema names.
  # Inputs:
  #   - out_sqlite_sources_var: Parent-scope variable for sqlite `*-odb.cxx`.
  #   - out_pgsql_sources_var: Parent-scope variable for postgre `*-odb.cxx`.
  #   - schema_dir: Schema directory basename.
  # Outputs:
  #   - <out_sqlite_sources_var> (PARENT_SCOPE): Expected sqlite ODB sources.
  #   - <out_pgsql_sources_var> (PARENT_SCOPE): Expected postgre ODB sources.
  cppbessot_get_schema_dir_path(_schema_dir_path "${schema_dir}")
  cppbessot_get_openapi_schema_names(_schema_names "${schema_dir}")

  set(_sqlite_sources)
  set(_pgsql_sources)
  foreach(_schema_name IN LISTS _schema_names)
    list(APPEND _sqlite_sources
      "${_schema_dir_path}/generated-odb-source/sqlite/${_schema_name}-odb.cxx")
    list(APPEND _pgsql_sources
      "${_schema_dir_path}/generated-odb-source/postgre/${_schema_name}-odb.cxx")
  endforeach()

  set(${out_sqlite_sources_var} "${_sqlite_sources}" PARENT_SCOPE)
  set(${out_pgsql_sources_var} "${_pgsql_sources}" PARENT_SCOPE)
endfunction()