# Unix SMB/CIFS implementation.
# Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2009-2012
# Copyright (C) Theresa Halloran <theresahalloran@gmail.com> 2011
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import optparse
import samba
from samba import colour
from samba.logger import get_samba_logger
from ldb import LdbError
import sys
import traceback
import textwrap


class Option(optparse.Option):
    SUPPRESS_HELP = optparse.SUPPRESS_HELP
    pass

# This help formatter does text wrapping and preserves newlines


class PlainHelpFormatter(optparse.IndentedHelpFormatter):
    def format_description(self, description=""):
        desc_width = self.width - self.current_indent
        indent = " " * self.current_indent
        paragraphs = description.split('\n')
        wrapped_paragraphs = [
            textwrap.fill(p,
                          desc_width,
                          initial_indent=indent,
                          subsequent_indent=indent)
            for p in paragraphs]
        result = "\n".join(wrapped_paragraphs) + "\n"
        return result

    def format_epilog(self, epilog):
        if epilog:
            return "\n" + epilog + "\n"
        else:
            return ""


class Command(object):
    """A samba-tool command."""

    def _get_short_description(self):
        return self.__doc__.splitlines()[0].rstrip("\n")

    short_description = property(_get_short_description)

    def _get_full_description(self):
        lines = self.__doc__.split("\n")
        return lines[0] + "\n" + textwrap.dedent("\n".join(lines[1:]))

    full_description = property(_get_full_description)

    def _get_name(self):
        name = self.__class__.__name__
        if name.startswith("cmd_"):
            return name[4:]
        return name

    name = property(_get_name)

    # synopsis must be defined in all subclasses in order to provide the
    # command usage
    synopsis = None
    takes_args = []
    takes_options = []
    takes_optiongroups = {}

    hidden = False

    raw_argv = None
    raw_args = None
    raw_kwargs = None

    def __init__(self, outf=sys.stdout, errf=sys.stderr):
        self.outf = outf
        self.errf = errf

    def usage(self, prog=None):
        parser, _ = self._create_parser(prog)
        parser.print_usage()

    def show_command_error(self, e):
        '''display a command error'''
        if isinstance(e, CommandError):
            (etype, evalue, etraceback) = e.exception_info
            inner_exception = e.inner_exception
            message = e.message
            force_traceback = False
        else:
            (etype, evalue, etraceback) = sys.exc_info()
            inner_exception = e
            message = "uncaught exception"
            force_traceback = True

        if isinstance(inner_exception, LdbError):
            (ldb_ecode, ldb_emsg) = inner_exception.args
            self.errf.write("ERROR(ldb): %s - %s\n" % (message, ldb_emsg))
        elif isinstance(inner_exception, AssertionError):
            self.errf.write("ERROR(assert): %s\n" % message)
            force_traceback = True
        elif isinstance(inner_exception, RuntimeError):
            self.errf.write("ERROR(runtime): %s - %s\n" % (message, evalue))
        elif type(inner_exception) is Exception:
            self.errf.write("ERROR(exception): %s - %s\n" % (message, evalue))
            force_traceback = True
        elif inner_exception is None:
            self.errf.write("ERROR: %s\n" % (message))
        else:
            self.errf.write("ERROR(%s): %s - %s\n" % (str(etype), message, evalue))
            force_traceback = True

        if force_traceback or samba.get_debug_level() >= 3:
            traceback.print_tb(etraceback, file=self.errf)

    def _create_parser(self, prog=None, epilog=None):
        parser = optparse.OptionParser(
            usage=self.synopsis,
            description=self.full_description,
            formatter=PlainHelpFormatter(),
            prog=prog, epilog=epilog)
        parser.add_options(self.takes_options)
        optiongroups = {}
        for name in sorted(self.takes_optiongroups.keys()):
            optiongroup = self.takes_optiongroups[name]
            optiongroups[name] = optiongroup(parser)
            parser.add_option_group(optiongroups[name])
        return parser, optiongroups

    def message(self, text):
        self.outf.write(text + "\n")

    def _run(self, *argv):
        parser, optiongroups = self._create_parser(argv[0])
        opts, args = parser.parse_args(list(argv))
        # Filter out options from option groups
        args = args[1:]
        kwargs = dict(opts.__dict__)
        for option_group in parser.option_groups:
            for option in option_group.option_list:
                if option.dest is not None:
                    del kwargs[option.dest]
        kwargs.update(optiongroups)

        # Check for a min a max number of allowed arguments, whenever possible
        # The suffix "?" means zero or one occurence
        # The suffix "+" means at least one occurence
        # The suffix "*" means zero or more occurences
        min_args = 0
        max_args = 0
        undetermined_max_args = False
        for i, arg in enumerate(self.takes_args):
            if arg[-1] != "?" and arg[-1] != "*":
                min_args += 1
            if arg[-1] == "+" or arg[-1] == "*":
                undetermined_max_args = True
            else:
                max_args += 1
        if (len(args) < min_args) or (not undetermined_max_args and len(args) > max_args):
            parser.print_usage()
            return -1

        self.raw_argv = list(argv)
        self.raw_args = args
        self.raw_kwargs = kwargs

        try:
            return self.run(*args, **kwargs)
        except Exception as e:
            self.show_command_error(e)
            return -1

    def run(self):
        """Run the command. This should be overridden by all subclasses."""
        raise NotImplementedError(self.run)

    def get_logger(self, name="", verbose=False, quiet=False, **kwargs):
        """Get a logger object."""
        return get_samba_logger(
            name=name or self.name, stream=self.errf,
            verbose=verbose, quiet=quiet,
            **kwargs)

    def apply_colour_choice(self, requested):
        """Heuristics to work out whether the user wants colour output, from a
        --color=yes|no|auto option. This alters the ANSI 16 bit colour
        "constants" in the colour module to be either real colours or empty
        strings.
        """
        requested = requested.lower()
        if requested == 'no':
            colour.switch_colour_off()

        elif requested == 'yes':
            colour.switch_colour_on()

        elif requested == 'auto':
            if (hasattr(self.outf, 'isatty') and self.outf.isatty()):
                colour.switch_colour_on()
            else:
                colour.switch_colour_off()

        else:
            raise CommandError("Unknown --color option: %s "
                               "please choose from yes, no, auto")


class SuperCommand(Command):
    """A samba-tool command with subcommands."""

    synopsis = "%prog <subcommand>"

    subcommands = {}

    def _run(self, myname, subcommand=None, *args):
        if subcommand in self.subcommands:
            return self.subcommands[subcommand]._run(
                "%s %s" % (myname, subcommand), *args)

        if subcommand == 'help':
            # pass the request down
            if len(args) > 0:
                sub = self.subcommands.get(args[0])
                if isinstance(sub, SuperCommand):
                    return sub._run("%s %s" % (myname, args[0]), 'help',
                                    *args[1:])
                elif sub is not None:
                    return sub._run("%s %s" % (myname, args[0]), '--help',
                                    *args[1:])

            subcommand = '--help'

        epilog = "\nAvailable subcommands:\n"
        subcmds = list(self.subcommands.keys())
        subcmds.sort()
        max_length = max([len(c) for c in subcmds])
        for cmd_name in subcmds:
            cmd = self.subcommands[cmd_name]
            if not cmd.hidden:
                epilog += "  %*s  - %s\n" % (
                    -max_length, cmd_name, cmd.short_description)
        epilog += "For more help on a specific subcommand, please type: %s <subcommand> (-h|--help)\n" % myname

        parser, optiongroups = self._create_parser(myname, epilog=epilog)
        args_list = list(args)
        if subcommand:
            args_list.insert(0, subcommand)
        opts, args = parser.parse_args(args_list)

        parser.print_help()
        return -1


class CommandError(Exception):
    """An exception class for samba-tool Command errors."""

    def __init__(self, message, inner_exception=None):
        self.message = message
        self.inner_exception = inner_exception
        self.exception_info = sys.exc_info()

    def __repr__(self):
        return "CommandError(%s)" % self.message
