#
#   Copyright 2013 Pixar
#
#   Licensed under the terms set forth in the LICENSE.txt file available at
#   https://opensubdiv.org/license.
#

# - Try to find the restructured text to HTML converter
#
# Once done this will define
#
#  DOCUTILS_FOUND - System has Docutils
#
#  RST2HTML_EXECUTABLE

find_package(PackageHandleStandardArgs)

find_program( RST2HTML_EXECUTABLE
    NAMES
        rst2html.py
        rst2html
    DOC
        "The Python Docutils reStructuredText to HTML converter"
)

if (RST2HTML_EXECUTABLE)
    # Note we only check for a python interpreter and use it for the command
    # on Windows.  It would be cleaner if we could agree that this is the
    # right way to do it for all platforms, or find a way that works for all
    # platforms uniformly.
    if (WIN32)
        find_package(PythonInterp)
        if (NOT PYTHON_EXECUTABLE)
            message(FATAL_ERROR "Could not find Python interpreter, which is required for Docutils")
        endif()
        execute_process(COMMAND ${PYTHON_EXECUTABLE} ${RST2HTML_EXECUTABLE} --version OUTPUT_VARIABLE VERSION_STRING )
    else()
        execute_process(COMMAND ${RST2HTML_EXECUTABLE} --version OUTPUT_VARIABLE VERSION_STRING )
    endif()

    # The above code may fail to find a version. Which will make the REGEX
    # REPLACE below fail and break the build. So we check for an empty
    # VERSION_STRING.
    if (NOT "${VERSION_STRING}" STREQUAL "")

        # find the version
        # ex : rst2html (Docutils 0.6 [release], Python 2.6.6, on linux2)
        string(REGEX MATCHALL "([^\ ]+\ |[^\ ]+$)" VERSION_TOKENS "${VERSION_STRING}")

        # isolate the 3rd. word in the string
        list (GET VERSION_TOKENS 2 VERSION_STRING)

        # remove white space
        string(REGEX REPLACE "[ \t]+$" "" VERSION_STRING ${VERSION_STRING})
        string(REGEX REPLACE "^[ \t]+" "" VERSION_STRING ${VERSION_STRING})

        set(DOCUTILS_VERSION ${VERSION_STRING})

    endif()

endif()

include(FindPackageHandleStandardArgs)

find_package_handle_standard_args(Docutils
    REQUIRED_VARS
        RST2HTML_EXECUTABLE
        DOCUTILS_VERSION
    VERSION_VAR
        DOCUTILS_VERSION
)

mark_as_advanced(
    RST2HTML_EXECUTABLE
)