#
# This file is distributed under the MIT License. See LICENSE.md for details.
#

# Extracts definitions and generates C++ headers and implementations from the
# given header files.
# The definitions must be embedded as described in the docs for
# tuple_tree_generator_extract_definitions_from_headers.
function(tuple_tree_generator_cpp_from_headers
  # Name of the target to generate the code
  TARGET_NAME
  # List of C++ headers
  HEADERS
  # Delimiter used to mark comments embedding type schemas
  DELIMITER
  NAMESPACE
  # Output directory
  OUTPUT_DIR
  # Include path prefix
  INCLUDE_PATH_PREFIX
  # Variable will be filled with the list of generated C++ headers
  GENERATED_HEADERS_VARIABLE
  # Variable will be filled with the list of generated C++ source files
  GENERATED_IMPLS_VARIABLE
)
  set(COLLECTED_YAML_PATH "${OUTPUT_DIR}/schema.yml")
  tuple_tree_generator_extract_definitions_from_headers(
    "${HEADERS}"
    "${DELIMITER}"
    "${COLLECTED_YAML_PATH}"
  )

  tuple_tree_generator_compute_generated_cpp_files(
    "${HEADERS}"
    "${OUTPUT_DIR}"
    LOCAL_GENERATED_HEADERS
    LOCAL_GENERATED_IMPLS
  )

  tuple_tree_generator_generate_cpp(
    "${COLLECTED_YAML_PATH}"
    "${NAMESPACE}"
    "${OUTPUT_DIR}"
    "${INCLUDE_PATH_PREFIX}"
    "${LOCAL_GENERATED_HEADERS}"
    "${LOCAL_GENERATED_IMPLS}"
  )

  set("${GENERATED_HEADERS_VARIABLE}" ${LOCAL_GENERATED_HEADERS} PARENT_SCOPE)
  set("${GENERATED_IMPLS_VARIABLE}" ${LOCAL_GENERATED_IMPLS} PARENT_SCOPE)

  add_custom_target(
    "${TARGET_NAME}"
    DEPENDS ${LOCAL_GENERATED_HEADERS} ${LOCAL_GENERATED_IMPLS}
  )
endfunction()

# Extracts tuple_tree_generator YAML definitions from the given header files
#
# The definitions have to be embedded in a c-style comment marked with the given
# delimiter, like so:
#
# /* DELIMITER
# <definition>
# DELIMITER */
function(tuple_tree_generator_extract_definitions_from_headers HEADERS DELIMITER OUTPUT_FILE)
  add_custom_command(
      OUTPUT "${OUTPUT_FILE}"
      COMMAND "${CMAKE_SOURCE_DIR}/scripts/tuple_tree_generator/extract_yaml.py"
      --output "${OUTPUT_FILE}"
      "${DELIMITER}"
      ${HEADERS}
      DEPENDS ${HEADERS}
  )
endfunction()

# Computes the list of headers and C++ source files that will be generated by
# tuple_tree_generator.
# Note: the output variables will be overwritten
function(tuple_tree_generator_compute_generated_cpp_files
  SOURCE_HEADERS
  OUTPUT_DIR
  GENERATED_HEADERS_VARIABLE
  GENERATED_IMPLS_VARIABLE
)
  # Empty output variables
  set(LOCAL_GENERATED_HEADERS_VARIABLE "${OUTPUT_DIR}/ForwardDecls.h")
  set(LOCAL_GENERATED_IMPLS_VARIABLE)

  foreach(HEADER ${SOURCE_HEADERS})
    get_filename_component(HEADER_FILENAME "${HEADER}" NAME)
    get_filename_component(HEADER_FILENAME_WE "${HEADER}" NAME_WE)
    set(EARLY_OUTPUT "${OUTPUT_DIR}/Early/${HEADER_FILENAME}")
    set(LATE_OUTPUT "${OUTPUT_DIR}/Late/${HEADER_FILENAME}")
    set(IMPL_OUTPUT "${OUTPUT_DIR}/Impl/${HEADER_FILENAME_WE}.cpp")
    list(APPEND LOCAL_GENERATED_HEADERS_VARIABLE "${EARLY_OUTPUT}")
    list(APPEND LOCAL_GENERATED_HEADERS_VARIABLE "${LATE_OUTPUT}")
    list(APPEND LOCAL_GENERATED_IMPLS_VARIABLE "${IMPL_OUTPUT}")
  endforeach()
  set("${GENERATED_HEADERS_VARIABLE}" ${LOCAL_GENERATED_HEADERS_VARIABLE} PARENT_SCOPE)
  set("${GENERATED_IMPLS_VARIABLE}" ${LOCAL_GENERATED_IMPLS_VARIABLE} PARENT_SCOPE)
endfunction()


set(TEMPLATES_DIR "${CMAKE_SOURCE_DIR}/scripts/tuple_tree_generator/tuple_tree_generator/templates")
set(TEMPLATES
  "${TEMPLATES_DIR}/class_forward_decls.h.tpl"
  "${TEMPLATES_DIR}/enum.h.tpl"
  "${TEMPLATES_DIR}/struct.h.tpl"
  "${TEMPLATES_DIR}/struct_forward_decls.h.tpl"
  "${TEMPLATES_DIR}/struct_late.h.tpl"
  "${TEMPLATES_DIR}/struct_impl.cpp.tpl"
)

# Generates headers and implementation C++ files
function(tuple_tree_generator_generate_cpp
  # Path to the yaml definitions
  YAML_DEFINITIONS
  # Base namespace of the generated classes (e.g. model)
  NAMESPACE
  # Output directory
  OUTPUT_DIR
  # Include path prefix
  INCLUDE_PATH_PREFIX
  # List of headers that are expected to be generated
  EXPECTED_GENERATED_HEADERS
  # List of implementation files expected to be generated
  EXPECTED_GENERATED_IMPLS
)
  set(SCRIPTS_ROOT_DIR "${CMAKE_SOURCE_DIR}/scripts/tuple_tree_generator")

  # The list of Python scripts is build as follows:
  #
  # find scripts/tuple_tree_generator -name "*.py" | sort | sed 's|scripts/tuple_tree_generator|"\${SCRIPTS_ROOT_DIR}|; s/$/"/
  #
  # TODO: detect and warn about extra files in those directories
  add_custom_command(
    COMMAND "${SCRIPTS_ROOT_DIR}/main.py"
            --namespace "${NAMESPACE}"
            --cpp-headers
            --include-path-prefix "${INCLUDE_PATH_PREFIX}"
            "${YAML_DEFINITIONS}"
            "${OUTPUT_DIR}"
    OUTPUT ${EXPECTED_GENERATED_HEADERS} ${EXPECTED_GENERATED_IMPLS}
    DEPENDS
      "${YAML_DEFINITIONS}"
      ${TEMPLATES}
      "${SCRIPTS_ROOT_DIR}/extract_yaml.py"
      "${SCRIPTS_ROOT_DIR}/main.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/__init__.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/definition/__init__.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/definition/definition.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/definition/enum.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/definition/struct.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/generators/__init__.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/generators/cppheaders.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/generators/generator.py"
      "${SCRIPTS_ROOT_DIR}/tuple_tree_generator/generators/jinja_utils.py"
  )
endfunction()