include(ShogunUtils)

# Meta dependencies
FIND_PACKAGE(PLY REQUIRED)
IF(NOT PLY_FOUND)
	message(FATAL_ERROR "Python module ply required for meta examples. Install or set BUILD_META_EXAMPLES=OFF")
ENDIF()

SET_SOURCE_FILES_PROPERTIES(${CTAGS_FILE} PROPERTIES GENERATED 1)

# get list of meta examples that can be built
INCLUDE(FindMetaExamples)
find_meta_examples()

# get parser and target languages needed to build the meta examples
SET(GENERATOR_DEPENDENCIES)
LIST(APPEND GENERATOR_DEPENDENCIES ${CMAKE_SOURCE_DIR}/examples/meta/generator/generate.py)
LIST(APPEND GENERATOR_DEPENDENCIES ${CMAKE_SOURCE_DIR}/examples/meta/generator/parse.py)
LIST(APPEND GENERATOR_DEPENDENCIES ${CMAKE_SOURCE_DIR}/examples/meta/generator/translate.py)
FILE(GLOB TARGET_LANGUAGES ${CMAKE_SOURCE_DIR}/examples/meta/generator/targets/*.json)
LIST(APPEND GENERATOR_DEPENDENCIES ${TARGET_LANGUAGES})

# parser generation
set(GENERATED_PARSER_FILES)
LIST(APPEND GENERATED_PARSER_FILES ${CMAKE_CURRENT_BINARY_DIR}/parser_files/parsetab.py)
LIST(APPEND GENERATED_PARSER_FILES ${CMAKE_CURRENT_BINARY_DIR}/parser_files/lextab.py)
add_custom_command(
    OUTPUT ${GENERATED_PARSER_FILES}
    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/generator/parse.py
    COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/parser_files
    COMMAND ${PYTHON_EXECUTABLE}
        ${CMAKE_CURRENT_SOURCE_DIR}/generator/parse.py
        --parser_files_dir ${CMAKE_CURRENT_BINARY_DIR}/parser_files
        --only_generate_parser_files)

add_custom_target(parse_lex_files ALL DEPENDS ${GENERATED_PARSER_FILES})

# list of interfaces for which we dont generate meta examples
SET(DISABLED_INTERFACES INTERFACE_PERL)

# handle the data path
IF (NOT EXISTS ${CMAKE_CURRENT_BINARY_DIR}/data)
    # copy data symlink to cmake binary dir so that we can execute meta examples in there
    CREATE_DATA_SYMLINK(${CMAKE_CURRENT_SOURCE_DIR}/data ${CMAKE_CURRENT_BINARY_DIR}/data)
ENDIF()
SET(SHOGUN_DATA ${CMAKE_CURRENT_BINARY_DIR}/data)

# translate the meta examples to the target languages using the .sg.in files
# first cmake will do variable substitution on @SHOGUN_DATA@ and generate .sg files
FOREACH(META_EXAMPLE_IN ${META_EXAMPLES})
    GET_META_EXAMPLE_VARS(${META_EXAMPLE_IN} EXAMPLE_NAME EXAMPLE_REL_DIR EXAMPLE_NAME_WITH_DIR)
    SET(BASENAME ${EXAMPLE_REL_DIR}/${EXAMPLE_NAME})

    SET(META_EXAMPLE ${CMAKE_CURRENT_BINARY_DIR}/src/${BASENAME}.sg)
    configure_file(${META_EXAMPLE_IN} ${META_EXAMPLE} @ONLY)

    # assume a structure <target_language>/<category>/listing.sg
    SET(EXAMPLE_LISTINGS)
    LIST(APPEND EXAMPLE_LISTINGS ${CMAKE_CURRENT_BINARY_DIR}/cpp/${BASENAME}.cpp)

    # FIXME
    # Hack to avoid generation of scala meta examples dependencies that will
    # not be generated by generate.py script (since there is no scala.json)
	LIST(REMOVE_ITEM AVAILABLE_INTERFACES INTERFACE_SCALA)
    FOREACH(interface ${AVAILABLE_INTERFACES})
        list(FIND DISABLED_INTERFACES ${interface} disabled)
        if (${disabled} STREQUAL "-1")
            GET_INTERFACE_VARS(${interface} DIRECTORY EXTENSION)
            LIST(APPEND EXAMPLE_LISTINGS ${CMAKE_CURRENT_BINARY_DIR}/${DIRECTORY}/${BASENAME}.${EXTENSION})
        endif()
    ENDFOREACH()
	LIST(APPEND AVAILABLE_INTERFACES INTERFACE_SCALA)

	# Set generate.py flags
	SET(GENERATOR_FLAGS
		-i ${META_EXAMPLE}
		-o ${CMAKE_CURRENT_BINARY_DIR}
		-t ${CMAKE_CURRENT_SOURCE_DIR}/generator/targets
		-g ${CTAGS_FILE}
		--parser_files_dir=${CMAKE_CURRENT_BINARY_DIR}/parser_files)

	# Enable variable storing only if we have enabled testing
	IF(ENABLE_TESTING)
		LIST(APPEND GENERATOR_FLAGS --store-vars)
	ENDIF()

    # Run example generation script
    SET(TEMP ${CMAKE_CURRENT_BINARY_DIR}/python/${EXAMPLE_REL_DIR}/${EXAMPLE_NAME}.py)
    add_custom_command(OUTPUT ${EXAMPLE_LISTINGS}
        COMMAND ${PYTHON_EXECUTABLE}
        ${CMAKE_CURRENT_SOURCE_DIR}/generator/generate.py ${GENERATOR_FLAGS}
		COMMENT "Generating example ${EXAMPLE_NAME_WITH_DIR}"
        DEPENDS ctags ${META_EXAMPLE_IN} ${GENERATOR_DEPENDENCIES}
            parse_lex_files)

    LIST(APPEND TRANSLATED_META_EXAMPLES ${EXAMPLE_LISTINGS})
ENDFOREACH()
SET_SOURCE_FILES_PROPERTIES(${TRANSLATED_META_EXAMPLES} PROPERTIES GENERATED TRUE)

add_custom_target(meta_examples ALL
    DEPENDS ${TRANSLATED_META_EXAMPLES})

INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/cpp
    DESTINATION share/shogun/examples
    COMPONENT ${DIRECTORY}-examples
    FILES_MATCHING PATTERN "*.cpp"
    PATTERN "CMakeFiles*" EXCLUDE
    )

# c++
IF (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/cpp AND NOT ${DISABLE_META_CPP})
    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/cpp)
ENDIF()

########### test all the enabled interfaces & install their files to examples

# temporarily disabled. While the interface fully works, the new API does not
# there is a potential bug in swig that needs fixing first
# see https://github.com/shogun-toolbox/shogun/issues/4177
LIST(APPEND DISABLED_INTERFACES INTERFACE_RUBY)

FOREACH(interface ${AVAILABLE_INTERFACES})
    list(FIND DISABLED_INTERFACES ${interface} disabled)
    if (${interface} AND ${disabled} STREQUAL "-1")
        GET_INTERFACE_VARS(${interface} DIRECTORY EXTENSION)

        INSTALL(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${DIRECTORY}
            DESTINATION share/shogun/examples
            COMPONENT ${DIRECTORY}-examples
            FILES_MATCHING PATTERN "*.${EXTENSION}"
            PATTERN "CMakeFiles*" EXCLUDE
            )

		add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${DIRECTORY})

	endif()
ENDFOREACH()