set(PROJ_PREFIX "" CACHE PATH "The path to the prefix of an Proj installation")

find_path(PROJ_INCLUDE_DIR NAMES proj.h proj_api.h
  PATHS
  ${PROJ_PREFIX}/include
  /opt/local/include
  /usr/include
  /usr/local/include
)

find_library(PROJ_LIBRARIES NAMES proj
  PATHS
  ${PROJ_PREFIX}/lib
  /opt/local/lib
  /usr/lib
  /usr/local/lib
)

if(PROJ_INCLUDE_DIR AND PROJ_LIBRARIES AND NOT TARGET PROJ)
  get_filename_component(PROJ_LIBRARY_DIR ${PROJ_LIBRARIES} PATH)
  set(PROJ_FOUND TRUE)
  add_library(Proj::Proj INTERFACE IMPORTED)
  set_target_properties(Proj::Proj PROPERTIES
      INTERFACE_INCLUDE_DIRECTORIES "${PROJ_INCLUDE_DIR}"
      INTERFACE_LINK_LIBRARIES "${PROJ_LIBRARIES}"
  )
endif()

if(PROJ_FOUND)
  if(NOT PROJ_FIND_QUIETLY)
    MESSAGE(STATUS "Found Proj: ${PROJ_LIBRARIES}")
  endif()
  set(HAVE_PROJ 1)
  if(EXISTS ${PROJ_INCLUDE_DIR}/proj.h)
    file(READ ${PROJ_INCLUDE_DIR}/proj.h proj_version)
    string(REGEX REPLACE "^.*PROJ_VERSION_MAJOR +([0-9]+).*$" "\\1" PROJ_VERSION_MAJOR "${proj_version}")
  elseif(EXISTS ${PROJ_INCLUDE_DIR}/proj_api.h)
    file(READ ${PROJ_INCLUDE_DIR}/proj_api.h proj_version)
    string(REGEX REPLACE "^.*PJ_VERSION ([0-9]+).*$" "\\1" PJ_VERSION "${proj_version}")
    string(REGEX REPLACE "([0-9])([0-9])([0-9])" "\\1" PROJ_VERSION_MAJOR "${PJ_VERSION}")
  endif()
  set(PROJ_VERSION_MAJOR "${PROJ_VERSION_MAJOR}" CACHE INTERNAL "")
elseif(PROJ_FOUND)
  if(PROJ_FIND_REQUIRED)
    message(FATAL_ERROR "Could not find Proj")
  endif()
endif()