# -*- coding: utf-8 -*-

# This file is distributed under the same License of Python
# Copyright (c) 2014 Oz Nahum Tiram  <nahumoz@gmail.com>

"""
build_manpage.py

Add a `build_manpage` command  to your setup.py.
To use this Command class import the class to your setup.py,
and add a command to call this class::

    from build_manpage import BuildManPage

    ...
    ...

    setup(
    ...
    ...
    cmdclass={
        'build_manpage': BuildManPage,
    )

You can then use the following setup command to produce a man page::

    $ python setup.py build_manpage --output=prog.1 --parser=yourmodule:argparser

"""


import datetime
from distutils.core import Command
from distutils.errors import DistutilsOptionError
import argparse


class BuildManPage(Command):

    """-O pwman.1 --parser=pwman:parser_options"""
    description = 'Generate man page from setup().'

    user_options = [
        ('output=', 'O', 'output file'),
        ('parser=', None, 'module path to optparser (e.g. mymod:func'),
    ]

    def initialize_options(self):
        self.output = None
        self.parser = None

    def finalize_options(self):
        if self.output is None:
            raise DistutilsOptionError('\'output\' option is required')
        if self.parser is None:
            raise DistutilsOptionError('\'parser\' option is required')
        mod_name, func_name = self.parser.split(':')
        fromlist = mod_name.split('.')
        try:
            mod = __import__(mod_name, fromlist=fromlist)
            self._parser = getattr(mod, func_name)(formatter_class=ManPageFormatter)
        except ImportError as err:
            raise err

        self._parser.formatter_class = ManPageFormatter
        self.announce('Writing man page %s' % self.output)
        self._today = datetime.date.today()

    def _markup(self, txt):
        return txt.replace('-', '\\-')

    def _write_header(self):
        appname = self.distribution.get_name()
        ret = []
        ret.append('.TH %s 1 %s\n' % (self._markup(appname),
                                      self._today.strftime('%Y\\-%m\\-%d')))
        description = self.distribution.get_description()
        if description:
            name = self._markup('%s - %s' % (self._markup(appname),
                                             description.splitlines()[0]))
        else:
            name = self._markup(appname)
        ret.append('.SH NAME\n%s\n' % name)

        if isinstance(self._parser, argparse.ArgumentParser):
            self._parser.prog = self.distribution.get_name()
            synopsis = self._parser.format_usage().split(':', 1)[1]
        else:
            synopsis = self._parser.get_usage()
        if synopsis:
            synopsis = synopsis.replace('%s ' % appname, '')
            ret.append('.SH SYNOPSIS\n \\fB%s\\fR %s\n' % (self._markup(appname),
                                                           synopsis))
        long_desc = self.distribution.get_long_description()
        if long_desc:
            long_desc = long_desc.replace('\n', '\n.br\n')
            ret.append('.SH DESCRIPTION\n%s\n' % self._markup(long_desc))
        return ''.join(ret)

    def _write_options(self):
        ret = ['.SH OPTIONS\n']
        ret.extend(self._parser.formatter_class.format_options(self._parser))

        return ''.join(ret)

    def _write_footer(self):
        ret = []
        appname = self.distribution.get_name()
        author = '%s <%s>' % (self.distribution.get_author(),
                              self.distribution.get_author_email())
        ret.append(('.SH AUTHORS\n.B %s\nwas written by %s.\n'
                    % (self._markup(appname), self._markup(author))))
        homepage = self.distribution.get_url()
        ret.append(('.SH DISTRIBUTION\nThe latest version of %s may '
                    'be downloaded from\n'
                    '%s\n\n'
                    % (self._markup(appname), self._markup(homepage),)))
        return ''.join(ret)

    def run(self):
        manpage = []
        manpage.append(self._write_header())
        manpage.append(self._write_options())
        manpage.append(self._write_footer())
        stream = open(self.output, 'w')
        stream.write(''.join(manpage))
        stream.close()


class ManPageFormatter(argparse.HelpFormatter):

    def _underline(self, string):
        return "\\fI\\s-1" + string + "\\s0\\fR"

    def _bold(self, string):
        if not string.strip().startswith('\\fB'):
            string = '\\fB' + string
        if not string.strip().endswith('\\fR'):
            string = string + '\\fR'
        return string

    @staticmethod
    def format_options(parser):
        formatter = parser._get_formatter()

        # positionals, optionals and user-defined groups
        for action_group in parser._action_groups:
            formatter.start_section(None)
            formatter.add_text(None)
            formatter.add_arguments(action_group._group_actions)
            formatter.end_section()

        # epilog
        formatter.add_text(parser.epilog)

        # determine help from format above
        return formatter.format_help()

    def _format_action_invocation(self, action):
        if not action.option_strings:
            metavar, = self._metavar_formatter(action, action.dest)(1)
            return metavar

        else:
            parts = []

            # if the Optional doesn't take a value, format is:
            #    -s, --long
            if action.nargs == 0:
                parts.extend([self._bold(action_str) for action_str in action.option_strings])

            # if the Optional takes a value, format is:
            #    -s ARGS, --long ARGS
            else:
                default = self._underline(action.dest.upper())
                args_string = self._format_args(action, default)
                for option_string in action.option_strings:
                    parts.append('%s %s' % (self._bold(option_string), args_string))

            return ', '.join(parts)

#  build.sub_commands.append(('build_manpage', None))