INCLUDE(ExternalProject)

SET(GFLAGS_SOURCES_DIR ${THIRD_PARTY_PATH}/gflags)
SET(GFLAGS_INSTALL_DIR ${THIRD_PARTY_PATH})
SET(GFLAGS_INCLUDE_DIR "${GFLAGS_INSTALL_DIR}/include" CACHE PATH "gflags include directory." FORCE)
IF(WIN32)
    set(GFLAGS_LIBRARIES "${GFLAGS_INSTALL_DIR}/lib/gflags.lib" CACHE FILEPATH "GFLAGS_LIBRARIES" FORCE)
ELSE(WIN32)
    set(GFLAGS_LIBRARIES "${GFLAGS_INSTALL_DIR}/lib/libgflags.a" CACHE FILEPATH "GFLAGS_LIBRARIES" FORCE)
ENDIF(WIN32)

INCLUDE_DIRECTORIES(${GFLAGS_INCLUDE_DIR})

ExternalProject_Add(
    extern_gflags
    ${EXTERNAL_PROJECT_LOG_ARGS}
    GIT_REPOSITORY  "https://github.com/gflags/gflags.git"
    PREFIX          ${GFLAGS_SOURCES_DIR}
    UPDATE_COMMAND  ""
    CMAKE_ARGS      -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
    CMAKE_ARGS      -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
    CMAKE_ARGS      -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
    CMAKE_ARGS      -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
    CMAKE_ARGS      -DCMAKE_INSTALL_PREFIX=${GFLAGS_INSTALL_DIR}
    CMAKE_ARGS      -DCMAKE_POSITION_INDEPENDENT_CODE=ON
    CMAKE_ARGS      -DBUILD_TESTING=OFF
    CMAKE_ARGS      -DCMAKE_BUILD_TYPE=Release
    CMAKE_CACHE_ARGS -DCMAKE_INSTALL_PREFIX:PATH=${GFLAGS_INSTALL_DIR}
    -DCMAKE_POSITION_INDEPENDENT_CODE:BOOL=ON
    -DCMAKE_BUILD_TYPE:STRING=Release
    )

ADD_LIBRARY(gflags STATIC IMPORTED GLOBAL)
SET_PROPERTY(TARGET gflags PROPERTY IMPORTED_LOCATION ${GFLAGS_LIBRARIES})
ADD_DEPENDENCIES(gflags extern_gflags)

LIST(APPEND external_project_dependencies gflags)