# Copyright (C) 2004, 2005 by Canonical Ltd

# 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

# TODO: Some way to get a list of external commands (defined by shell
# scripts) so that they can be included in the help listing as well.
# It should be enough to just list the plugin directory and look for
# executable files with reasonable names.

# TODO: `help commands --all` should show hidden commands

global_help = \
"""Bazaar-NG -- a free distributed version-control tool
http://bazaar-ng.org/

WARNING: This is an unstable development version.
         Please keep backups.

Basic commands:

  bzr init      makes this branch versioned
  bzr branch    make a copy of another branch

  bzr add       make files or directories versioned
  bzr ignore    ignore a file or pattern
  bzr mv        move or rename a versioned file

  bzr status    summarize changes in working copy
  bzr diff      show detailed diffs

  bzr merge     pull in changes from another branch
  bzr commit    save some or all changes

  bzr log       show history of changes
  bzr check     validate storage

Use e.g. 'bzr help init' for more details, or
'bzr help commands' for all commands.
"""


import sys


def help(topic=None, outfile = None):
    if outfile == None:
        outfile = sys.stdout
    if topic == None:
        outfile.write(global_help)
    elif topic == 'commands':
        help_commands(outfile = outfile)
    else:
        help_on_command(topic, outfile = outfile)


def command_usage(cmd_object):
    """Return single-line grammar for command.

    Only describes arguments, not options.
    """
    s = 'bzr ' + cmd_object.name() + ' '
    for aname in cmd_object.takes_args:
        aname = aname.upper()
        if aname[-1] in ['$', '+']:
            aname = aname[:-1] + '...'
        elif aname[-1] == '?':
            aname = '[' + aname[:-1] + ']'
        elif aname[-1] == '*':
            aname = '[' + aname[:-1] + '...]'
        s += aname + ' '
            
    assert s[-1] == ' '
    s = s[:-1]
    
    return s


def help_on_command(cmdname, outfile=None):
    from bzrlib.commands import get_cmd_object

    cmdname = str(cmdname)

    if outfile == None:
        outfile = sys.stdout

    cmd_object = get_cmd_object(cmdname)

    doc = cmd_object.help()
    if doc == None:
        raise NotImplementedError("sorry, no detailed help yet for %r" % cmdname)

    print >>outfile, 'usage:', command_usage(cmd_object) 

    if cmd_object.aliases:
        print >>outfile, 'aliases:',
        print >>outfile, ', '.join(cmd_object.aliases)

    print >>outfile

    outfile.write(doc)
    if doc[-1] != '\n':
        outfile.write('\n')
    
    help_on_options(cmd_object.takes_options, outfile=None)


def help_on_options(options, outfile=None):
    from bzrlib.commands import SHORT_OPTIONS
    
    if not options:
        return
    
    if outfile == None:
        outfile = sys.stdout

    outfile.write('\noptions:\n')
    for on in options:
        l = '    --' + on
        for shortname, longname in SHORT_OPTIONS.items():
            if longname == on:
                l += ', -' + shortname
                break
        outfile.write(l + '\n')


def help_commands(outfile=None):
    """List all commands"""
    from bzrlib.commands import (builtin_command_names,
                                 plugin_command_names,
                                 get_cmd_object)

    if outfile == None:
        outfile = sys.stdout

    names = set()                       # to eliminate duplicates
    names.update(builtin_command_names())
    names.update(plugin_command_names())
    names = list(names)
    names.sort()

    for cmd_name in names:
        cmd_object = get_cmd_object(cmd_name)
        if cmd_object.hidden:
            continue
        print >>outfile, command_usage(cmd_object)
        cmd_help = cmd_object.help()
        if cmd_help:
            firstline = cmd_help.split('\n', 1)[0]
            print >>outfile, '    ' + firstline