include(ExternalProject)

set(OPENSSL_INSTALL ${THIRD_PARTY_DIR}/openssl)
set(OPENSSL_INCLUDE_DIR ${THIRD_PARTY_DIR}/openssl/include)
set(OPENSSL_LIBRARY_DIR ${THIRD_PARTY_DIR}/openssl/lib)

set(OPENSSL_TAR_URL https://github.com/openssl/openssl/archive/OpenSSL_1_1_1g.tar.gz)
use_mirror(VARIABLE OPENSSL_TAR_URL URL ${OPENSSL_TAR_URL})
set(OPENSSL_URL_HASH dd32f35dd5d543c571bc9ebb90ebe54e)
set(OPENSSL_SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/openssl)

if(WIN32)
  set(OPENSSL_BUILD_LIBRARY_DIR ${OPENSSL_INSTALL}/lib)
  set(OPENSSL_LIBRARY_NAMES ssl.lib crypto.lib)
elseif(APPLE AND ("${CMAKE_GENERATOR}" STREQUAL "Xcode"))
  set(OPENSSL_BUILD_LIBRARY_DIR ${OPENSSL_INSTALL}/lib)
  set(OPENSSL_LIBRARY_NAMES libssl.a libcrypto.a)
else()
  set(OPENSSL_BUILD_LIBRARY_DIR ${OPENSSL_INSTALL}/lib)
  set(OPENSSL_LIBRARY_NAMES libssl.a libcrypto.a)
endif()

foreach(LIBRARY_NAME ${OPENSSL_LIBRARY_NAMES})
  list(APPEND OPENSSL_STATIC_LIBRARIES ${OPENSSL_LIBRARY_DIR}/${LIBRARY_NAME})
  list(APPEND OPENSSL_BUILD_STATIC_LIBRARIES ${OPENSSL_BUILD_LIBRARY_DIR}/${LIBRARY_NAME})
endforeach()

if(THIRD_PARTY)

  include(ProcessorCount)
  ProcessorCount(PROC_NUM)
  ExternalProject_Add(
    openssl
    PREFIX openssl
    URL ${OPENSSL_TAR_URL}
    URL_HASH MD5=${OPENSSL_URL_HASH}
    UPDATE_COMMAND ""
    CONFIGURE_COMMAND ${OPENSSL_SOURCE_DIR}/src/openssl/config --prefix=${OPENSSL_INSTALL}
    BUILD_BYPRODUCTS ${OPENSSL_STATIC_LIBRARIES}
    BUILD_COMMAND make -j${PROC_NUM}
    INSTALL_COMMAND make install_sw)

endif(THIRD_PARTY)