# CxxProject 1.0.0
# ----------------

if (NOT __CXX_INCLUDED)
  set(__CXX_INCLUDED TRUE)
  include(CheckCXXCompilerFlag)

  # ---------------------------------------------------------------------------
  # C++ COMPILER SUPPORT:
  #
  #   * cxx_detect_cflags(out, ...)
  #   * cxx_detect_standard(out)
  # ---------------------------------------------------------------------------
  function(cxx_detect_cflags out)
    set(out_array ${${out}})

    foreach(flag ${ARGN})
      string(REGEX REPLACE "[-=:;/.]" "_" flag_signature "${flag}")
      check_cxx_compiler_flag(${flag} "__CxxFlag_${flag_signature}")
      if(${__CxxFlag_${flag_signature}})
        list(APPEND out_array "${flag}")
      endif()
    endforeach()

    set(${out} "${out_array}" PARENT_SCOPE)
  endfunction()

  function(cxx_detect_standard out)
    set(out_array)
    cxx_detect_cflags(out_array "-std=c++14" "-std=c++11" "-std=c++0x")

    # Keep only the first flag detected, which keeps the highest version supported.
    if(out_array)
      list(GET out_array 0 out_array)
    endif()

    set(out_array ${${out}} ${out_array})
    set(${out} "${out_array}" PARENT_SCOPE)
  endfunction()

  function(cxx_print_cflags cflags_any cflags_dbg cflags_rel)
    foreach(flag ${cflags_any})
      message("     ${flag}")
    endforeach()
    foreach(flag ${cflags_dbg})
      message("     ${flag} [DEBUG]")
    endforeach()
    foreach(flag ${cflags_rel})
      message("     ${flag} [RELEASE]")
    endforeach()
  endfunction()

  # -----------------------------------------------------------------------------
  # This part detects the c++ compiler and fills basic CXX_... variables to make
  # integration with that compiler easier. It provides the most common flags in
  # a cross-platform way.
  # -----------------------------------------------------------------------------
  set(CXX_DEFINE        "-D") # Define a preprocessor macro: "${CXX_DEFINE}VAR=1"
  set(CXX_INCLUDE       "-I") # Define an include directory: "${CXX_INCLUDE}PATH"

  set(CXX_CFLAGS_SSE    "")   # Compiler flags to build a file that uses SSE    intrinsics.
  set(CXX_CFLAGS_SSE2   "")   # Compiler flags to build a file that uses SSE2   intrinsics.
  set(CXX_CFLAGS_SSE3   "")   # Compiler flags to build a file that uses SSE3   intrinsics.
  set(CXX_CFLAGS_SSSE3  "")   # Compiler flags to build a file that uses SSSE3  intrinsics.
  set(CXX_CFLAGS_SSE4_1 "")   # Compiler flags to build a file that uses SSE4.1 intrinsics.
  set(CXX_CFLAGS_SSE4_2 "")   # Compiler flags to build a file that uses SSE4.2 intrinsics.
  set(CXX_CFLAGS_AVX    "")   # Compiler flags to build a file that uses AVX    intrinsics.
  set(CXX_CFLAGS_AVX2   "")   # Compiler flags to build a file that uses AVX2   intrinsics.

  if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
    set(CXX_DEFINE "/D")
    set(CXX_INCLUDE "/I")

    if(CMAKE_CL_64)
      # 64-bit MSVC compiler doesn't like /arch:SSE[2] as it's implicit.
      list(APPEND CXX_CFLAGS_SSE "${CXX_DEFINE}__SSE__=1")
      list(APPEND CXX_CFLAGS_SSE2 "${CXX_DEFINE}__SSE__=1;${CXX_DEFINE}__SSE2__=1")
    else()
      cxx_detect_cflags(CXX_CFLAGS_SSE "/arch:SSE")
      if(CXX_CFLAGS_SSE)
        list(APPEND CXX_CFLAGS_SSE "${CXX_DEFINE}__SSE__=1")
      endif()

      cxx_detect_cflags(CXX_CFLAGS_SSE2 "/arch:SSE2")
      if(CXX_CFLAGS_SSE2)
        list(APPEND CXX_CFLAGS_SSE2 "${CXX_DEFINE}__SSE__=1;${CXX_DEFINE}__SSE2__=1")
      endif()
    endif()

    # MSVC doesn't provide any preprocessor definitions to detect SSE3+,
    # these unify MSVC with definitions defined by Clang|GCC|Intel.
    if(CXX_CFLAGS_SSE2)
      list(APPEND CXX_CFLAGS_SSE3   "${CXX_CFLAGS_SSE2};${CXX_DEFINE}__SSE3__=1")
      list(APPEND CXX_CFLAGS_SSSE3  "${CXX_CFLAGS_SSE3};${CXX_DEFINE}__SSSE3__=1")
      list(APPEND CXX_CFLAGS_SSE4_1 "${CXX_CFLAGS_SSSE3};${CXX_DEFINE}__SSE4_1__=1")
      list(APPEND CXX_CFLAGS_SSE4_2 "${CXX_CFLAGS_SSE4_1};${CXX_DEFINE}__SSE4_2__=1")
    endif()

    # When using AVX and AVX2 MSVC does define '__AVX__' and '__AVX2__', respectively.
    cxx_detect_cflags(CXX_CFLAGS_AVX  "/arch:AVX")
    cxx_detect_cflags(CXX_CFLAGS_AVX2 "/arch:AVX2")

    if(CXX_CFLAGS_AVX)
      list(APPEND CXX_CFLAGS_AVX "${CXX_DEFINE}__SSE__=1;${CXX_DEFINE}__SSE2__=1;${CXX_DEFINE}__SSE3__=1;${CXX_DEFINE}__SSSE3__=1;${CXX_DEFINE}__SSE4_1__=1;${CXX_DEFINE}__SSE4_2__=1")
    endif()
    if(CXX_CFLAGS_AVX2)
      list(APPEND CXX_CFLAGS_AVX2 "${CXX_DEFINE}__SSE__=1;${CXX_DEFINE}__SSE2__=1;${CXX_DEFINE}__SSE3__=1;${CXX_DEFINE}__SSSE3__=1;${CXX_DEFINE}__SSE4_1__=1;${CXX_DEFINE}__SSE4_2__=1")
    endif()
  elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel" AND WIN32)
    # Intel on Windows uses CL syntax.
    set(CXX_DEFINE "/D")
    set(CXX_INCLUDE "/I")

    # Intel deprecated /arch:SSE, so it's implicit. In contrast to MSVC, Intel
    # also provides /arch:SSE3+ options and uses the same definitions as GCC
    # and Clang, so no magic needed here.
    cxx_detect_cflags(CXX_CFLAGS_SSE2   "/arch:SSE2")
    cxx_detect_cflags(CXX_CFLAGS_SSE3   "/arch:SSE3")
    cxx_detect_cflags(CXX_CFLAGS_SSSE3  "/arch:SSSE3")
    cxx_detect_cflags(CXX_CFLAGS_SSE4_1 "/arch:SSE4.1")
    cxx_detect_cflags(CXX_CFLAGS_SSE4_2 "/arch:SSE4.2")
    cxx_detect_cflags(CXX_CFLAGS_AVX    "/arch:AVX")
    cxx_detect_cflags(CXX_CFLAGS_AVX2   "/arch:AVX2")
  else()
    cxx_detect_cflags(CXX_CFLAGS_SSE    "-msse")
    cxx_detect_cflags(CXX_CFLAGS_SSE2   "-msse2")
    cxx_detect_cflags(CXX_CFLAGS_SSE3   "-msse3")
    cxx_detect_cflags(CXX_CFLAGS_SSSE3  "-mssse3")
    cxx_detect_cflags(CXX_CFLAGS_SSE4_1 "-msse4.1")
    cxx_detect_cflags(CXX_CFLAGS_SSE4_2 "-msse4.2")
    cxx_detect_cflags(CXX_CFLAGS_AVX    "-mavx")
    cxx_detect_cflags(CXX_CFLAGS_AVX2   "-mavx2")
  endif()

  # ---------------------------------------------------------------------------
  # Function
  #   cxx_project(product)
  #
  # Create a master project or embed other project in a master project.
  # ---------------------------------------------------------------------------
  function(cxx_project product)
    string(TOUPPER "${product}" PRODUCT)

    set(MODE_EMBED ${${PRODUCT}_EMBED})
    set(MODE_STATIC ${${PRODUCT}_STATIC})

    # EMBED implies STATIC.
    if(MODE_EMBED)
      set(MODE_STATIC TRUE)
      set(${PRODUCT}_STATIC TRUE PARENT_SCOPE)
    endif()

    # Deduce source and include directories. By default CxxProject assumes that
    # both source and include files are located at './src'.
    set(SOURCE_DIR "${${PRODUCT}_SOURCE_DIR}")
    set(INCLUDE_DIR "${${PRODUCT}_INCLUDE_DIR}")

    if(NOT SOURCE_DIR)
      set(SOURCE_DIR "${${PRODUCT}_DIR}/src")
      set(${PRODUCT}_SOURCE_DIR "${SOURCE_DIR}" PARENT_SCOPE)
    endif()

    if(NOT INCLUDE_DIR)
      set(INCLUDE_DIR "${SOURCE_DIR}")
      set(${PRODUCT}_INCLUDE_DIR "${INCLUDE_DIR}" PARENT_SCOPE)
    endif()

    set(DEPS               "") # Dependencies (list of libraries) for the linker.
    set(LIBS               "") # Dependencies with project included, for consumers.
    set(CFLAGS             "") # Public compiler flags.
    set(PRIVATE_CFLAGS     "") # Private compiler flags independent of build type.
    set(PRIVATE_CFLAGS_DBG "") # Private compiler flags used by debug builds.
    set(PRIVATE_CFLAGS_REL "") # Private compiler flags used by release builds.
    set(PRIVATE_LFLAGS     "") # Private linker flags.

    if(MODE_EMBED)
      list(APPEND CFLAGS         "${CXX_DEFINE}${PRODUCT}_EMBED")
      list(APPEND PRIVATE_CFLAGS "${CXX_DEFINE}${PRODUCT}_EMBED")
    endif()

    if(MODE_STATIC)
      list(APPEND CFLAGS         "${CXX_DEFINE}${PRODUCT}_STATIC")
      list(APPEND PRIVATE_CFLAGS "${CXX_DEFINE}${PRODUCT}_STATIC")
    endif()

    # PUBLIC properties - usable by third parties.
    set(${PRODUCT}_DEPS   "${DEPS}"   PARENT_SCOPE)
    set(${PRODUCT}_LIBS   "${LIBS}"   PARENT_SCOPE)
    set(${PRODUCT}_CFLAGS "${CFLAGS}" PARENT_SCOPE)

    # PRIVATE properties - only used during build.
    set(${PRODUCT}_PRIVATE_CFLAGS     "${PRIVATE_CFLAGS}"     PARENT_SCOPE)
    set(${PRODUCT}_PRIVATE_CFLAGS_DBG "${PRIVATE_CFLAGS_DBG}" PARENT_SCOPE)
    set(${PRODUCT}_PRIVATE_CFLAGS_REL "${PRIVATE_CFLAGS_REL}" PARENT_SCOPE)
    set(${PRODUCT}_PRIVATE_LFLAGS     "${PRIVATE_LFLAGS}"     PARENT_SCOPE)
  endfunction()

  function(cxx_project_info product)
    string(TOUPPER "${product}" PRODUCT)

    set(BUILD_MODE "")
    set(BUILD_TEST "")

    if(${PRODUCT}_EMBED)
      set(BUILD_MODE "Embed")
    elseif(${PRODUCT}_STATIC)
      set(BUILD_MODE "Static")
    else()
      set(BUILD_MODE "Shared")
    endif()

    if(${PRODUCT}_BUILD_TEST)
      set(BUILD_TEST "On")
    else()
      set(BUILD_TEST "Off")
    endif()

    message("-- [${product}]")
    message("   BuildMode=${BUILD_MODE}")
    message("   BuildTest=${BUILD_TEST}")
    message("   ${PRODUCT}_DIR=${${PRODUCT}_DIR}")
    message("   ${PRODUCT}_DEPS=${${PRODUCT}_DEPS}")
    message("   ${PRODUCT}_LIBS=${${PRODUCT}_LIBS}")
    message("   ${PRODUCT}_CFLAGS=${${PRODUCT}_CFLAGS}")
    message("   ${PRODUCT}_SOURCE_DIR=${${PRODUCT}_SOURCE_DIR}")
    message("   ${PRODUCT}_INCLUDE_DIR=${${PRODUCT}_INCLUDE_DIR}")
    message("   ${PRODUCT}_PRIVATE_CFLAGS=")
    cxx_print_cflags(
      "${${PRODUCT}_PRIVATE_CFLAGS}"
      "${${PRODUCT}_PRIVATE_CFLAGS_DBG}"
      "${${PRODUCT}_PRIVATE_CFLAGS_REL}")
  endfunction()

  function(cxx_add_source product out src_dir)
    string(TOUPPER "${product}" PRODUCT)

    set(src_path "${${PRODUCT}_SOURCE_DIR}/${src_dir}")
    set(src_array)

    foreach(file ${ARGN})
      set(src_file "${src_path}/${file}")
      set(src_cflags "")

      if(file MATCHES "\\.c|\\.cc|\\.cxx|\\.cpp|\\.m|\\.mm")
        if(file MATCHES "_sse\\." AND NOT "${CXX_CFLAGS_SSE}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSE})
        endif()
        if(file MATCHES "_sse2\\." AND NOT "${CXX_CFLAGS_SSE2}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSE2})
        endif()
        if(file MATCHES "_sse3\\." AND NOT "${CXX_CFLAGS_SSE3}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSE3})
        endif()
        if(file MATCHES "_ssse3\\." AND NOT "${CXX_CFLAGS_SSSE3}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSSE3})
        endif()
        if(file MATCHES "_sse4_1\\." AND NOT "${CXX_CFLAGS_SSE4_1}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSE4_1})
        endif()
        if(file MATCHES "_sse4_2\\." AND NOT "${CXX_CFLAGS_SSE4_2}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_SSE4_2})
        endif()
        if(file MATCHES "_avx\\." AND NOT "${CXX_CFLAGS_AVX}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_AVX})
        endif()
        if(file MATCHES "_avx2\\." AND NOT "${CXX_CFLAGS_AVX2}" STREQUAL "")
          list(APPEND src_cflags ${CXX_CFLAGS_AVX2})
        endif()

        if(NOT "${src_cflags}" STREQUAL "")
          set_source_files_properties(${src_file} PROPERTIES COMPILE_FLAGS ${src_cflags})
        endif()
      endif()
      list(APPEND src_array ${src_file})
    endforeach()
    source_group(${src_dir} FILES ${src_array})

    set(out_tmp ${${out}})
    list(APPEND out_tmp ${src_array})
    set("${out}" "${out_tmp}" PARENT_SCOPE)
  endfunction()

  function(cxx_add_library product target src deps cflags cflags_dbg cflags_rel)
    string(TOUPPER "${product}" PRODUCT)

    if(NOT ${PRODUCT}_STATIC)
      add_library(${target} SHARED ${src})
    else()
      add_library(${target} STATIC ${src})
    endif()

    target_link_libraries(${target} ${deps})
    if (NOT "${${PRODUCT}_PRIVATE_LFLAGS}" STREQUAL "")
      set_target_properties(${target} PROPERTIES LINK_FLAGS "${${PRODUCT}_PRIVATE_LFLAGS}")
    endif()

    if(CMAKE_BUILD_TYPE)
      if("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
        target_compile_options(${target} PRIVATE ${cflags} ${cflags_dbg})
      else()
        target_compile_options(${target} PRIVATE ${cflags} ${cflags_rel})
      endif()
    else()
      target_compile_options(${target} PRIVATE ${cflags} $<$<CONFIG:Debug>:${cflags_dbg}> $<$<NOT:$<CONFIG:Debug>>:${cflags_rel}>)
    endif()

    if(NOT ${PRODUCT}_STATIC)
      install(TARGETS ${target} DESTINATION "lib${LIB_SUFFIX}")
    endif()
  endfunction()

  function(cxx_add_executable product target src deps cflags cflags_dbg cflags_rel)
    string(TOUPPER "${product}" PRODUCT)
    add_executable(${target} ${src})

    target_link_libraries(${target} ${deps})
    if (NOT "${${PRODUCT}_PRIVATE_LFLAGS}" STREQUAL "")
      set_target_properties(${target} PROPERTIES LINK_FLAGS "${${PRODUCT}_PRIVATE_LFLAGS}")
    endif()

    if(CMAKE_BUILD_TYPE)
      if("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
        target_compile_options(${target} PRIVATE ${cflags} ${cflags_dbg})
      else()
        target_compile_options(${target} PRIVATE ${cflags} ${cflags_rel})
      endif()
    else()
      target_compile_options(${target} PRIVATE ${cflags} $<$<CONFIG:Debug>:${cflags_dbg}> $<$<NOT:$<CONFIG:Debug>>:${cflags_rel}>)
    endif()

    if(NOT ${PRODUCT}_STATIC)
      install(TARGETS ${target} DESTINATION "lib${LIB_SUFFIX}")
    endif()
  endfunction()
endif()