cmake_minimum_required(VERSION 3.7)

if(POLICY CMP0114)
    cmake_policy(SET CMP0114 NEW)
endif()

include(ExternalProject)

set(ANTLR4_ROOT ${CMAKE_CURRENT_BINARY_DIR}/antlr4_runtime/src/antlr4_runtime)
set(ANTLR4_INCLUDE_DIRS ${ANTLR4_ROOT}/runtime/Cpp/runtime/src)
if (NOT DEFINED ANTLR4_GIT_REPOSITORY)
    set(ANTLR4_GIT_REPOSITORY https://github.com/antlr/antlr4.git)
endif()
if(NOT DEFINED ANTLR4_TAG)
    # Set to branch name to keep library updated at the cost of needing to rebuild after 'clean'
    # Set to commit hash to keep the build stable and does not need to rebuild after 'clean'
    set(ANTLR4_TAG master)
endif()

# Ensure that the include dir already exists at configure time (to avoid cmake erroring
# on non-existent include dirs)
file(MAKE_DIRECTORY "${ANTLR4_INCLUDE_DIRS}")

if(${CMAKE_GENERATOR} MATCHES "Visual Studio.*")
    set(ANTLR4_OUTPUT_DIR ${ANTLR4_ROOT}/runtime/Cpp/runtime/$(Configuration))
elseif(${CMAKE_GENERATOR} MATCHES "Xcode.*")
    set(ANTLR4_OUTPUT_DIR ${ANTLR4_ROOT}/runtime/Cpp/runtime/$(CONFIGURATION))
else()
    set(ANTLR4_OUTPUT_DIR ${ANTLR4_ROOT}/runtime/Cpp/runtime)
endif()

if(MSVC)
    set(ANTLR4_STATIC_LIBRARIES
            ${ANTLR4_OUTPUT_DIR}/antlr4-runtime-static.lib)
    set(ANTLR4_SHARED_LIBRARIES
            ${ANTLR4_OUTPUT_DIR}/antlr4-runtime.lib)
    set(ANTLR4_RUNTIME_LIBRARIES
            ${ANTLR4_OUTPUT_DIR}/antlr4-runtime.dll)
else()
    set(ANTLR4_STATIC_LIBRARIES
            ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.a)
    if(MINGW)
        set(ANTLR4_SHARED_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.dll.a)
        set(ANTLR4_RUNTIME_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.dll)
    elseif(CYGWIN)
        set(ANTLR4_SHARED_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.dll.a)
        set(ANTLR4_RUNTIME_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/cygantlr4-runtime-4.13.1.dll)
    elseif(APPLE)
        set(ANTLR4_RUNTIME_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.dylib)
    else()
        set(ANTLR4_RUNTIME_LIBRARIES
                ${ANTLR4_OUTPUT_DIR}/libantlr4-runtime.so)
    endif()
endif()

if(${CMAKE_GENERATOR} MATCHES ".* Makefiles")
    # This avoids
    # 'warning: jobserver unavailable: using -j1. Add '+' to parent make rule.'
    set(ANTLR4_BUILD_COMMAND $(MAKE))
elseif(${CMAKE_GENERATOR} MATCHES "Visual Studio.*")
    set(ANTLR4_BUILD_COMMAND
            ${CMAKE_COMMAND}
            --build .
            --config $(Configuration)
            --target)
elseif(${CMAKE_GENERATOR} MATCHES "Xcode.*")
    set(ANTLR4_BUILD_COMMAND
            ${CMAKE_COMMAND}
            --build .
            --config $(CONFIGURATION)
            --target)
else()
    set(ANTLR4_BUILD_COMMAND
            ${CMAKE_COMMAND}
            --build .
            --target)
endif()

if(NOT DEFINED ANTLR4_WITH_STATIC_CRT)
    set(ANTLR4_WITH_STATIC_CRT ON)
endif()

if(ANTLR4_ZIP_REPOSITORY)
    ExternalProject_Add(
            antlr4_runtime
            PREFIX antlr4_runtime
            URL ${ANTLR4_ZIP_REPOSITORY}
            DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR}
            BUILD_COMMAND ""
            BUILD_IN_SOURCE 1
            SOURCE_DIR ${ANTLR4_ROOT}
            SOURCE_SUBDIR runtime/Cpp
            CMAKE_CACHE_ARGS
            -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
            -DWITH_STATIC_CRT:BOOL=${ANTLR4_WITH_STATIC_CRT}
            -DDISABLE_WARNINGS:BOOL=ON
            -DCMAKE_CXX_STANDARD:STRING=17 # if desired, compile the runtime with a different C++ standard
            # -DCMAKE_CXX_STANDARD:STRING=${CMAKE_CXX_STANDARD} # alternatively, compile the runtime with the same C++ standard as the outer project
            INSTALL_COMMAND ""
            EXCLUDE_FROM_ALL 1)
else()
    ExternalProject_Add(
            antlr4_runtime
            PREFIX antlr4_runtime
            GIT_REPOSITORY ${ANTLR4_GIT_REPOSITORY}
            GIT_TAG ${ANTLR4_TAG}
            GIT_SHALLOW 1
            DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR}
            BUILD_COMMAND ""
            BUILD_IN_SOURCE 1
            SOURCE_DIR ${ANTLR4_ROOT}
            SOURCE_SUBDIR runtime/Cpp
            CMAKE_CACHE_ARGS
            -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
            -DWITH_STATIC_CRT:BOOL=${ANTLR4_WITH_STATIC_CRT}
            -DDISABLE_WARNINGS:BOOL=ON
            -DCMAKE_CXX_STANDARD:STRING=17 # if desired, compile the runtime with a different C++ standard
            # -DCMAKE_CXX_STANDARD:STRING=${CMAKE_CXX_STANDARD} # alternatively, compile the runtime with the same C++ standard as the outer project
            INSTALL_COMMAND ""
            EXCLUDE_FROM_ALL 1)
endif()

# Separate build step as rarely people want both
set(ANTLR4_BUILD_DIR ${ANTLR4_ROOT})
if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.14.0")
    # CMake 3.14 builds in above's SOURCE_SUBDIR when BUILD_IN_SOURCE is true
    set(ANTLR4_BUILD_DIR ${ANTLR4_ROOT}/runtime/Cpp)
endif()

ExternalProject_Add_Step(
        antlr4_runtime
        build_static
        COMMAND ${ANTLR4_BUILD_COMMAND} antlr4_static
        # Depend on target instead of step (a custom command)
        # to avoid running dependent steps concurrently
        DEPENDS antlr4_runtime
        BYPRODUCTS ${ANTLR4_STATIC_LIBRARIES}
        EXCLUDE_FROM_MAIN 1
        WORKING_DIRECTORY ${ANTLR4_BUILD_DIR})
ExternalProject_Add_StepTargets(antlr4_runtime build_static)

add_library(antlr4_static STATIC IMPORTED)
add_dependencies(antlr4_static antlr4_runtime-build_static)
set_target_properties(antlr4_static PROPERTIES
        IMPORTED_LOCATION ${ANTLR4_STATIC_LIBRARIES})
target_include_directories(antlr4_static
        INTERFACE
        ${ANTLR4_INCLUDE_DIRS}
)

ExternalProject_Add_Step(
        antlr4_runtime
        build_shared
        COMMAND ${ANTLR4_BUILD_COMMAND} antlr4_shared
        # Depend on target instead of step (a custom command)
        # to avoid running dependent steps concurrently
        DEPENDS antlr4_runtime
        BYPRODUCTS ${ANTLR4_SHARED_LIBRARIES} ${ANTLR4_RUNTIME_LIBRARIES}
        EXCLUDE_FROM_MAIN 1
        WORKING_DIRECTORY ${ANTLR4_BUILD_DIR})
ExternalProject_Add_StepTargets(antlr4_runtime build_shared)

add_library(antlr4_shared SHARED IMPORTED)
add_dependencies(antlr4_shared antlr4_runtime-build_shared)
set_target_properties(antlr4_shared PROPERTIES
        IMPORTED_LOCATION ${ANTLR4_RUNTIME_LIBRARIES})
target_include_directories(antlr4_shared
        INTERFACE
        ${ANTLR4_INCLUDE_DIRS}
)

if(ANTLR4_SHARED_LIBRARIES)
    set_target_properties(antlr4_shared PROPERTIES
            IMPORTED_IMPLIB ${ANTLR4_SHARED_LIBRARIES})
endif()

macro(antlr4cpp_process_grammar
        antlr4cpp_project
        antlr4cpp_project_namespace
        antlr4cpp_grammar_lexer
        antlr4cpp_grammar_parser)

    if(EXISTS "${ANTLR4CPP_JAR_LOCATION}")
        message(STATUS "Found antlr tool: ${ANTLR4CPP_JAR_LOCATION}")
    else()
        message(FATAL_ERROR "Unable to find antlr tool. ANTLR4CPP_JAR_LOCATION:${ANTLR4CPP_JAR_LOCATION}")
    endif()
    message(STATUS "GENERATED_SRC_DIR: ${ANTLR4CPP_GENERATED_SRC_DIR}")

    add_custom_target("antlr4cpp_generation_${antlr4cpp_project_namespace}"
            COMMAND
            ${CMAKE_COMMAND} -E make_directory "${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace}"
            COMMAND
            "${Java_JAVA_EXECUTABLE}" -jar "${ANTLR4CPP_JAR_LOCATION}" -Werror -Dlanguage=Cpp -listener -visitor -o "${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace}" -package ${antlr4cpp_project_namespace} "${antlr4cpp_grammar_lexer}" "${antlr4cpp_grammar_parser}"
            WORKING_DIRECTORY "${CMAKE_BINARY_DIR}"
            DEPENDS "${antlr4cpp_grammar_lexer}" "${antlr4cpp_grammar_parser}"
            COMMENT "Generating ${antlr4cpp_project_namespace} with antlr4cpp"
    )
    # message(STATUS "Generate Command: ${Java_JAVA_EXECUTABLE} -jar ${ANTLR4CPP_JAR_LOCATION} -Werror -Dlanguage=Cpp -listener -visitor -o ${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace} -package ${antlr4cpp_project_namespace} ${antlr4cpp_grammar_lexer} ${antlr4cpp_grammar_parser}")

    # Find all the input files
    FILE(GLOB generated_files ${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace}/*.cpp)

    # export generated cpp files into list
    foreach(generated_file ${generated_files})
        list(APPEND antlr4cpp_src_files_${antlr4cpp_project_namespace} ${generated_file})
        set_source_files_properties(
                ${generated_file}
                PROPERTIES
                COMPILE_FLAGS -Wno-overloaded-virtual
        )
    endforeach(generated_file)
    message(STATUS "Antlr4Cpp  ${antlr4cpp_project_namespace} Generated: ${generated_files}")

    # export generated include directory
    set(antlr4cpp_include_dirs_${antlr4cpp_project_namespace} ${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace})
    message(STATUS "Antlr4Cpp ${antlr4cpp_project_namespace} include: ${ANTLR4CPP_GENERATED_SRC_DIR}/${antlr4cpp_project_namespace}")

endmacro()