# Try to find zlib
# Once done, this will define
#
# ZLIB_FOUND          - system has zlib
# ZLIB_INCLUDE_DIRS   - zlib include directories
# ZLIB_LIBRARIES      - libraries needed to use zlib
# ZLIB_LIBRARY_STATIC - static zlib library
#
# and the following imported targets
#
# ZLIB::ZLIB
# ZLIB::ZLIB_STATIC
#

if (TARGET ZLIB::ZLIB)
  message(STATUS "INFO: zlib already found")
  return()
endif()

find_package(PkgConfig)
pkg_check_modules(PC_ZLIB QUIET zlib)
set(ZLIB_VERSION ${PC_ZLIB_VERSION})

find_path(ZLIB_INCLUDE_DIR
  NAMES zlib.h
  PATHS ${ZLIB_ROOT} ${PC_ZLIB_INCLUDEDIR} ${PC_ZLIB_INCLUDE_DIRS})

find_library(ZLIB_LIBRARY
  NAME z
  HINTS ${ZLIB_ROOT} ${PC_ZLIB_LIBDIR} ${PC_ZLIB_LIBRARY_DIRS}
  PATH_SUFFIXES ${CMAKE_INSTALL_LIBDIR})

if (Linux)
  find_library(ZLIB_LIBRARY_STATIC
    NAMES libz.a
    PATHS ${ZLIB_ROOT} ${PC_ZLIB_LIBDIR} ${PC_ZLIB_LIBRARY_DIRS}
    PATH_SUFFIXES ${CMAKE_INSTALL_LIBDIR})
else ()
   set(ZLIB_LIBRARY_STATIC ${ZLIB_LIBRARY})
endif ()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(zlib
  REQUIRED_VARS ZLIB_LIBRARY ZLIB_INCLUDE_DIR ZLIB_LIBRARY_STATIC
  VERSION_VAR ZLIB_VERSION)

mark_as_advanced(ZLIB_FOUND ZLIB_INCLUDE_DIR ZLIB_LIBRARY ZLIB_LIBRARY_STATIC)

if (ZLIB_FOUND AND NOT TARGET ZLIB::ZLIB AND NOT TARGET ZLIB::ZLIB_STATIC)
  add_library(ZLIB::ZLIB UNKNOWN IMPORTED)
  set_target_properties(ZLIB::ZLIB PROPERTIES
    IMPORTED_LOCATION "${ZLIB_LIBRARY}"
    INTERFACE_INCLUDE_DIRECTORIES "${ZLIB_INCLUDE_DIR}")

  add_library(ZLIB::ZLIB_STATIC UNKNOWN IMPORTED)
  set_target_properties(ZLIB::ZLIB_STATIC PROPERTIES
    IMPORTED_LOCATION "${ZLIB_LIBRARY_STATIC}"
    INTERFACE_INCLUDE_DIRECTORIES "${ZLIB_INCLUDE_DIR}")
endif()

set(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})
set(ZLIB_LIBRARIES ${ZLIB_LIBRARY})
unset(ZLIB_INCLUDE_DIR)
unset(ZLIB_LIBRARY)