#.rst:
# FindLua
# -------
#
#
#
# Locate Lua library This module defines
#
# ::
#
#   LUA_FOUND          - if false, do not try to link to Lua
#   LUA_EXECUTABLE     - path to lua executable
#   LUA_LIBRARIES      - both lua and lualib
#   LUA_INCLUDE_DIR    - where to find lua.h
#   LUA_VERSION_STRING - the version of Lua found
#   LUA_VERSION_MAJOR  - the major version of Lua
#   LUA_VERSION_MINOR  - the minor version of Lua
#   LUA_VERSION_PATCH  - the patch version of Lua
#
#
#
# Note that the expected include convention is
#
# ::
#
#   #include "lua.h"
#
# and not
#
# ::
#
#   #include <lua/lua.h>
#
# This is because, the lua location is not standardized and may exist in
# locations other than lua/

#=============================================================================
# Copyright 2007-2009 Kitware, Inc.
# Copyright 2013 Rolf Eike Beer <eike@sf-mail.de>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

find_program(LUA_EXECUTABLE NAMES lua luajit lua51 lua5.1 lua52 lua5.2 lua53 lua5.3 luajit21 luajit20 DOC "lua executable")
if (APPLE AND LUA_EXECUTABLE MATCHES "\\.luaenv/shims")
  execute_process(COMMAND luaenv which lua RESULT_VARIABLE STATUS OUTPUT_VARIABLE LUA_EXECUTABLE ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
endif()

if (LUA_EXECUTABLE)
  get_filename_component(LUAENV_ROOT ${LUA_EXECUTABLE} DIRECTORY)
  get_filename_component(LUAENV_ROOT ${LUAENV_ROOT} DIRECTORY)
endif()

find_path(LUA_INCLUDE_DIR lua.h
  HINTS
    ENV LUA_DIR
  PATH_SUFFIXES
    include/lua51 include/lua5.1 include/lua-5.1
    include/lua52 include/lua5.2 include/lua-5.2
    include/lua53 include/lua5.3 include/lua-5.3
    include/luajit-2.1 include/luajit-2.0
    include/lua include
  PATHS
    ${LUAENV_ROOT}
    ~/Library/Frameworks
    /Library/Frameworks
    /sw # Fink
    /opt/local # DarwinPorts
    /opt/csw # Blastwave
    /opt
)

find_library(LUA_LIBRARY
  NAMES lua5.1 lua51 lua5.2 lua52 lua5.3 lua53 luajit-5.1 lua
  HINTS
    ENV LUA_DIR
  PATH_SUFFIXES lib
  PATHS
    ${LUAENV_ROOT}
    ~/Library/Frameworks
    /Library/Frameworks
    /sw
    /opt/local
    /opt/csw
    /opt
)

if (LUA_LIBRARY)
    # include the math library for Unix
    if (UNIX AND NOT APPLE AND NOT BEOS)
        find_library(LUA_MATH_LIBRARY m)
        set(LUA_LIBRARIES "${LUA_LIBRARY};${LUA_MATH_LIBRARY}")
    # For Windows and Mac, don't need to explicitly include the math library
    else ()
        set(LUA_LIBRARIES "${LUA_LIBRARY}")
    endif ()
endif()

if (LUA_INCLUDE_DIR AND EXISTS "${LUA_INCLUDE_DIR}/lua.h")
    # At least 5.[012] have different ways to express the version
    # so all of them need to be tested. Lua 5.2 defines LUA_VERSION
    # and LUA_RELEASE as joined by the C preprocessor, so avoid those.
    file(STRINGS "${LUA_INCLUDE_DIR}/lua.h" lua_version_strings
         REGEX "^#define[ \t]+LUA_(RELEASE[ \t]+\"Lua [0-9]|VERSION([ \t]+\"Lua [0-9]|_[MR])).*")

    string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_MAJOR[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_MAJOR ";${lua_version_strings};")
    if (LUA_VERSION_MAJOR MATCHES "^[0-9]+$")
        string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_MINOR[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_MINOR ";${lua_version_strings};")
        string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_RELEASE[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_PATCH ";${lua_version_strings};")
        set(LUA_VERSION_STRING "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}.${LUA_VERSION_PATCH}")
    else ()
        string(REGEX REPLACE ".*;#define[ \t]+LUA_RELEASE[ \t]+\"Lua ([0-9.]+)\"[ \t]*;.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
        if (NOT LUA_VERSION_STRING MATCHES "^[0-9.]+$")
            string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION[ \t]+\"Lua ([0-9.]+)\"[ \t]*;.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
        endif ()
        string(REGEX REPLACE "^([0-9]+)\\.[0-9.]*$" "\\1" LUA_VERSION_MAJOR "${LUA_VERSION_STRING}")
        string(REGEX REPLACE "^[0-9]+\\.([0-9]+)[0-9.]*$" "\\1" LUA_VERSION_MINOR "${LUA_VERSION_STRING}")
        string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]).*" "\\1" LUA_VERSION_PATCH "${LUA_VERSION_STRING}")
    endif ()

    unset(lua_version_strings)
endif()

include(FindPackageHandleStandardArgs)
# handle the QUIETLY and REQUIRED arguments and set LUA_FOUND to TRUE if
# all listed variables are TRUE
find_package_handle_standard_args(Lua
                                  REQUIRED_VARS LUA_LIBRARIES LUA_INCLUDE_DIR
                                  VERSION_VAR LUA_VERSION_STRING)

mark_as_advanced(LUA_INCLUDE_DIR LUA_LIBRARY LUA_MATH_LIBRARY)