#
#     Copyright 2013 Pixar
#
#     Licensed under the Apache License, Version 2.0 (the "License");
#     you may not use this file except in compliance with the License
#     and the following modification to it: Section 6 Trademarks.
#     deleted and replaced with:
#
#     6. Trademarks. This License does not grant permission to use the
#     trade names, trademarks, service marks, or product names of the
#     Licensor and its affiliates, except as required for reproducing
#     the content of the NOTICE file.
#
#     You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing,
#     software distributed under the License is distributed on an
#     "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
#     either express or implied.  See the License for the specific
#     language governing permissions and limitations under the
#     License.
#

# Try to find GLFW library and include path.
# Once done this will define
#
# GLFW_FOUND
# GLFW_INCLUDE_DIR
# GLFW_LIBRARIES
#

find_path( GLFW_INCLUDE_DIR 
    NAMES
        GL/glfw.h
        GLFW/glfw3.h
    PATHS
        ${GLFW_LOCATION}/include
        $ENV{GLFW_LOCATION}/include
        $ENV{PROGRAMFILES}/GLFW/include
        ${OPENGL_INCLUDE_DIR}
        /usr/openwin/share/include
        /usr/openwin/include
        /usr/X11R6/include
        /usr/include/X11
        /opt/graphics/OpenGL/include
        /opt/graphics/OpenGL/contrib/libglfw
        /usr/local/include
        /usr/include/GL
        /usr/include
    DOC 
        "The directory where GL/glfw.h resides"
)

if (WIN32)
    if(CYGWIN)
        find_library( GLFW_glfw_LIBRARY 
            NAMES
                glfw32
            PATHS
                ${GLFW_LOCATION}/lib
                ${GLFW_LOCATION}/lib/x64
                $ENV{GLFW_LOCATION}/lib
                ${OPENGL_LIBRARY_DIR}
                /usr/lib
                /usr/lib/w32api
                /usr/local/lib
                /usr/X11R6/lib
            DOC 
                "The GLFW library"
        )
    else()
        find_library( GLFW_glfw_LIBRARY
            NAMES 
                glfw32 
                glfw32s 
                glfw
                glfw3
            PATHS
                ${GLFW_LOCATION}/lib
                ${GLFW_LOCATION}/lib/x64
                ${GLFW_LOCATION}/lib-msvc110
                $ENV{GLFW_LOCATION}/lib
                ${PROJECT_SOURCE_DIR}/extern/glfw/bin
                ${PROJECT_SOURCE_DIR}/extern/glfw/lib
                $ENV{PROGRAMFILES}/GLFW/lib
                ${OPENGL_LIBRARY_DIR}
            DOC 
                "The GLFW library"
        )
    endif()
else ()
    if (APPLE)
        find_library( GLFW_glfw_LIBRARY glfw
            NAMES 
                glfw
                glfw3
            PATHS
                ${GLFW_LOCATION}/lib
                ${GLFW_LOCATION}/lib/cocoa
                $ENV{GLFW_LOCATION}/lib
                $ENV{GLFW_LOCATION}/lib/cocoa
                /usr/local/lib
        )
        set(GLFW_cocoa_LIBRARY "-framework Cocoa" CACHE STRING "Cocoa framework for OSX")
        set(GLFW_iokit_LIBRARY "-framework IOKit" CACHE STRING "IOKit framework for OSX")
    else ()
        # (*)NIX
        
        find_package(X11 REQUIRED)
        
        if(NOT X11_Xrandr_FOUND)
            message(FATAL_ERROR "Xrandr library not found - required for GLFW")
        endif()

        if(NOT X11_xf86vmode_FOUND)
            message(FATAL_ERROR "xf86vmode library not found - required for GLFW")
        endif()

        list(APPEND GLFW_x11_LIBRARY ${X11_Xrandr_LIB} ${X11_Xxf86vm_LIB})

        find_library( GLFW_glfw_LIBRARY
            NAMES 
                glfw
                glfw3
            PATHS
                ${GLFW_LOCATION}/lib
                $ENV{GLFW_LOCATION}/lib
                ${GLFW_LOCATION}/lib/x11
                $ENV{GLFW_LOCATION}/lib/x11
                /usr/lib
                /usr/local/lib
                /usr/openwin/lib
                /usr/X11R6/lib
            DOC 
                "The GLFW library"
        )
    endif (APPLE)
endif (WIN32)

set( GLFW_FOUND "NO" )

if(GLFW_INCLUDE_DIR)

    if(GLFW_glfw_LIBRARY)
        set( GLFW_LIBRARIES ${GLFW_glfw_LIBRARY} ${GLFW_x11_LIBRARY} ${GLFW_cocoa_LIBRARY} ${GLFW_iokit_LIBRARY} )        
        set( GLFW_FOUND "YES" )
        set (GLFW_LIBRARY ${GLFW_LIBRARIES})
        set (GLFW_INCLUDE_PATH ${GLFW_INCLUDE_DIR})
    endif(GLFW_glfw_LIBRARY)


    # Tease the GLFW_VERSION numbers from the lib headers
    function(parseVersion FILENAME VARNAME)
            
        set(PATTERN "^#define ${VARNAME}.*$")
        
        file(STRINGS "${GLFW_INCLUDE_DIR}/${FILENAME}" TMP REGEX ${PATTERN})
        
        string(REGEX MATCHALL "[0-9]+" TMP ${TMP})
        
        set(${VARNAME} ${TMP} PARENT_SCOPE)
        
    endfunction()


    if(EXISTS "${GLFW_INCLUDE_DIR}/GL/glfw.h")

        parseVersion(GL/glfw.h GLFW_VERSION_MAJOR)
        parseVersion(GL/glfw.h GLFW_VERSION_MINOR)
        parseVersion(GL/glfw.h GLFW_VERSION_REVISION)

    elseif(EXISTS "${GLFW_INCLUDE_DIR}/GLFW/glfw3.h")

        parseVersion(GLFW/glfw3.h GLFW_VERSION_MAJOR)
        parseVersion(GLFW/glfw3.h GLFW_VERSION_MINOR)
        parseVersion(GLFW/glfw3.h GLFW_VERSION_REVISION)
 
    endif()

    if(${GLFW_VERSION_MAJOR} OR ${GLFW_VERSION_MINOR} OR ${GLFW_VERSION_REVISION})
        set(GLFW_VERSION "${GLFW_VERSION_MAJOR}.${GLFW_VERSION_MINOR}.${GLFW_VERSION_REVISION}")
        set(GLFW_VERSION_STRING "${GLFW_VERSION}")
        mark_as_advanced(GLFW_VERSION)
    endif()
    
endif(GLFW_INCLUDE_DIR)

include(FindPackageHandleStandardArgs)

find_package_handle_standard_args(GLFW 
    REQUIRED_VARS
        GLFW_INCLUDE_DIR
        GLFW_LIBRARIES
    VERSION_VAR
        GLFW_VERSION
)

mark_as_advanced(
  GLFW_INCLUDE_DIR
  GLFW_LIBRARIES
  GLFW_glfw_LIBRARY
  GLFW_cocoa_LIBRARY
)