include(ExternalProject)

set(FLATBUFFERS_URL https://github.com/google/flatbuffers/archive/v1.12.0.tar.gz)

set(FLATBUFFERS_INSTALL_PREFIX ${THIRD_PARTY_DIR}/flatbuffers)
set(FLATBUFFERS_INSTALL_INCLUDEDIR include)
set(FLATBUFFERS_INSTALL_LIBDIR lib)
set(FLATBUFFERS_INSTALL_BINDIR bin)

use_mirror(VARIABLE FLATBUFFERS_URL URL ${FLATBUFFERS_URL})

set(FLATBUFFERS_INCLUDE_DIR ${FLATBUFFERS_INSTALL_PREFIX}/${FLATBUFFERS_INSTALL_INCLUDEDIR})
set(FLATBUFFERS_LIBRARY_DIR ${FLATBUFFERS_INSTALL_PREFIX}/${FLATBUFFERS_INSTALL_LIBDIR})
set(FLATBUFFERS_BINARY_DIR ${FLATBUFFERS_INSTALL_PREFIX}/${FLATBUFFERS_INSTALL_BINDIR})

set(FLATC_EXECUTABLE_NAME flatc)
set(FLATBUFFERS_FLATC_EXECUTABLE ${FLATBUFFERS_BINARY_DIR}/${FLATC_EXECUTABLE_NAME})

set(FLATBUFFERS_LIBRARY_NAMES libflatbuffers.a)
foreach(LIBRARY_NAME ${FLATBUFFERS_LIBRARY_NAMES})
  list(APPEND FLATBUFFERS_STATIC_LIBRARIES ${FLATBUFFERS_LIBRARY_DIR}/${LIBRARY_NAME})
endforeach()

if(THIRD_PARTY)

  ExternalProject_Add(
    flatbuffers
    PREFIX flatbuffers
    URL ${FLATBUFFERS_URL}
    URL_MD5 c62ffefb3d4548b127cca14ce047f16c
    UPDATE_COMMAND bash -c "rm -f BUILD || true"
    BUILD_IN_SOURCE 1
    SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/flatbuffers/src/flatbuffers
    BUILD_BYPRODUCTS ${FLATBUFFERS_STATIC_LIBRARIES}
    CMAKE_ARGS -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
               -DCMAKE_INSTALL_PREFIX=${FLATBUFFERS_INSTALL_PREFIX}
               -DCMAKE_INSTALL_INCLUDEDIR=${FLATBUFFERS_INSTALL_INCLUDEDIR}
               -DCMAKE_INSTALL_LIBDIR=${FLATBUFFERS_INSTALL_LIBDIR}
               -DCMAKE_INSTALL_BINDIR=${FLATBUFFERS_INSTALL_BINDIR}
               -DCMAKE_INSTALL_MESSAGE:STRING=${CMAKE_INSTALL_MESSAGE}
               -DFLATBUFFERS_BUILD_TESTS=OFF)
endif(THIRD_PARTY)