cmake_minimum_required(VERSION 3.12)

project(libspng C)

set(CMAKE_C_STANDARD 99)

set(SPNG_MAJOR 0)
set(SPNG_MINOR 7)
set(SPNG_REVISION 4)
set(SPNG_VERSION ${SPNG_MAJOR}.${SPNG_MINOR}.${SPNG_REVISION})

option(ENABLE_OPT "Enable architecture-specific optimizations" ON)
option(SPNG_SHARED "Build shared lib" ON)
option(SPNG_STATIC "Build static lib" ON)
option(BUILD_EXAMPLES "Build examples" ON)

include(GNUInstallDirs)
include(CMakePackageConfigHelpers)

if(NOT CMAKE_HOST_WIN32)
    set(MATH_LIBRARY "m")
else()
    set(MATH_LIBRARY "")
endif()

if(NOT ENABLE_OPT)
    add_definitions( -DSPNG_DISABLE_OPT=1 )
endif()

set(spng_TARGETS "")

set(spng_SOURCES spng/spng.c)

if(SPNG_SHARED)
    add_library(spng SHARED ${spng_SOURCES})
    list(APPEND spng_TARGETS spng)

    if(BUILD_EXAMPLES)
        add_executable(example examples/example.c)
        target_link_libraries(example PRIVATE spng)
    endif()
endif()

if(SPNG_STATIC)
    add_library(spng_static STATIC ${spng_SOURCES})
    target_compile_definitions(spng_static PUBLIC SPNG_STATIC)
    list(APPEND spng_TARGETS spng_static)
endif()

find_package(ZLIB REQUIRED)
foreach(spng_TARGET ${spng_TARGETS})
    target_include_directories(${spng_TARGET} PUBLIC
      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/spng>
      $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
    )
    target_link_libraries(${spng_TARGET} PRIVATE ZLIB::ZLIB)
    target_link_libraries(${spng_TARGET} PRIVATE ${MATH_LIBRARY})
endforeach()

set(project_config "${CMAKE_CURRENT_BINARY_DIR}/SPNGConfig.cmake")
set(project_version_config "${CMAKE_CURRENT_BINARY_DIR}/SPNGConfigVersion.cmake")
set(targets_export_name SPNGTargets)
set(config_install_dir "${CMAKE_INSTALL_LIBDIR}/cmake/spng")

configure_package_config_file(cmake/Config.cmake.in ${project_config}
  INSTALL_DESTINATION ${config_install_dir}
)

write_basic_package_version_file(${project_version_config}
  VERSION ${SPNG_VERSION}
  COMPATIBILITY SameMajorVersion
)

install(
  TARGETS ${spng_TARGETS}
  EXPORT ${targets_export_name}
  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
  INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)

install(FILES spng/spng.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})

install(
  FILES ${project_config} ${project_version_config}
  DESTINATION ${config_install_dir}
)

install(
  EXPORT ${targets_export_name}
  NAMESPACE "spng::"
  DESTINATION ${config_install_dir}
)

if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
    set(prefix      ${CMAKE_INSTALL_PREFIX})
    set(exec_prefix ${CMAKE_INSTALL_PREFIX})
    set(libdir      ${CMAKE_INSTALL_FULL_LIBDIR})
    set(includedir  ${CMAKE_INSTALL_FULL_INCLUDEDIR})
    set(LIBS        "-lm")

    foreach(libname ${spng_TARGETS})
        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/libspng.pc.in ${CMAKE_CURRENT_BINARY_DIR}/cmake/lib${libname}.pc @ONLY)

        install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cmake/lib${libname}.pc DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
    endforeach()
endif()