[PATCH 3/3] pwclient: rework multi-command help text

[Brian Norris]

Our --help handling is convoluted and confusing, since we're hacking
around using some of argparse's built-in features (like generating
--help arguments for us). It seems like we were hacking around the
conflict between -h used for hashes and -h used for automatic help
flags. Fortunately, Python's argparse provides us with a
'conflict_handler' which will resolve these conflicts for us.

Altogether, this patch means that 'pwclient --help' will not generate a
full recursive print of all subcommand helps (arguably a good thing),
but it provides better automatic formatting of all the supported
subcommands and eliminates some awkward code.

Sample runs:

$ pwclient
usage: pwclient [-h]
                {apply,git-am,get,info,projects,states,view,update,list,search}
                ...

optional arguments:
  -h, --help            show this help message and exit

Commands:
  {apply,git-am,get,info,projects,states,view,update,list,search}
    apply               Apply a patch (in the current dir, using -p1)
    git-am              Apply a patch to current git branch using "git am".
    get                 Download a patch and save it locally
    info                Display patchwork info about a given patch ID
    projects            List all projects
    states              Show list of potential patch states
    view                View a patch
    update              Update patch
    list                List patches, using the optional filters specified
                        below and an optional substring to search for patches
                        by name
    search              Alias for "list"

Use 'pwclient <command> --help' for more info

$ pwclient info --help
usage: pwclient info [--help] [-h HASH] [-p PROJECT] [ID [ID ...]]

positional arguments:
  ID          Patch ID

optional arguments:
  --help      show this help message and exit
  -h HASH     Lookup by patch hash
  -p PROJECT  Lookup patch in project

Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
IMO, this is altogether nicer. I've been using this since I wrote it back in
November.

 apps/patchwork/bin/pwclient | 67 ++++++---------------------------------------
 1 file changed, 9 insertions(+), 58 deletions(-)

diff --git a/apps/patchwork/bin/pwclient b/apps/patchwork/bin/pwclient
index f2cec63492de..ec146cda618b 100755
--- a/apps/patchwork/bin/pwclient
+++ b/apps/patchwork/bin/pwclient
@@ -328,31 +328,6 @@ def patch_id_from_hash(rpc, project, hash):
 
 auth_actions = ['update']
 
-# unfortunately we currently have to revert to this ugly hack..
-class _RecursiveHelpAction(argparse._HelpAction):
-
-    def __call__(self, parser, namespace, values, option_string=None):
-        parser.print_help()
-        print
-
-        subparsers_actions = [
-            action for action in parser._actions
-            if isinstance(action, argparse._SubParsersAction)
-        ]
-        hash_n_id_actions = set(['hash', 'id', 'help'])
-        for subparsers_action in subparsers_actions:
-            for choice, subparser in subparsers_action.choices.items():
-                # gross but the whole thing is..
-                if (len(subparser._actions) == 3 \
-                    and set([a.dest for a in subparser._actions]) \
-                        == hash_n_id_actions) \
-                   or len(subparser._actions) == 0:
-                    continue
-                print("command '{}'".format(choice))
-                print(subparser.format_help())
-
-        parser.exit()
-
 def main():
     hash_parser = argparse.ArgumentParser(add_help=False)
     hash_parser.add_argument(
@@ -407,38 +382,22 @@ def main():
         'patch_name', metavar='STR', nargs='?',
         help='substring to search for patches by name',
     )
-    help_parser = argparse.ArgumentParser(add_help=False)
-    help_parser.add_argument(
-        '--help', action='help', help=argparse.SUPPRESS,
-        #help='''show this help message and exit'''
-    )
 
     action_parser = argparse.ArgumentParser(
         prog='pwclient',
-        add_help=False,
-        formatter_class=argparse.RawDescriptionHelpFormatter,
-        epilog='''(apply | get | info | view | update) (-h HASH | ID [ID ...])''',
-    )
-    action_parser.add_argument(
-        '--help',
-        #action='help',
-        action=_RecursiveHelpAction,
-        help='''Print this help text'''
+        epilog='Use \'pwclient <command> --help\' for more info',
     )
 
     subparsers = action_parser.add_subparsers(
         title='Commands',
-        metavar=''
     )
     apply_parser = subparsers.add_parser(
-        'apply', parents=[hash_parser, help_parser],
-        add_help=False,
+        'apply', parents=[hash_parser], conflict_handler='resolve',
         help='''Apply a patch (in the current dir, using -p1)'''
     )
     apply_parser.set_defaults(subcmd='apply')
     git_am_parser = subparsers.add_parser(
-        'git-am', parents=[hash_parser, help_parser],
-        add_help=False,
+        'git-am', parents=[hash_parser], conflict_handler='resolve',
         help='''Apply a patch to current git branch using "git am".'''
     )
     git_am_parser.set_defaults(subcmd='git_am')
@@ -448,38 +407,32 @@ def main():
         help='''pass --signoff to git-am'''
     )
     get_parser = subparsers.add_parser(
-        'get', parents=[hash_parser, help_parser],
-        add_help=False,
+        'get', parents=[hash_parser], conflict_handler='resolve',
         help='''Download a patch and save it locally'''
     )
     get_parser.set_defaults(subcmd='get')
     info_parser = subparsers.add_parser(
-        'info', parents=[hash_parser, help_parser],
-        add_help=False,
+        'info', parents=[hash_parser], conflict_handler='resolve',
         help='''Display patchwork info about a given patch ID'''
     )
     info_parser.set_defaults(subcmd='info')
     projects_parser = subparsers.add_parser(
         'projects',
-        add_help=False,
         help='''List all projects'''
     )
     projects_parser.set_defaults(subcmd='projects')
     states_parser = subparsers.add_parser(
         'states',
-        add_help=False,
         help='''Show list of potential patch states'''
     )
     states_parser.set_defaults(subcmd='states')
     view_parser = subparsers.add_parser(
-        'view', parents=[hash_parser, help_parser],
-        add_help=False,
+        'view', parents=[hash_parser], conflict_handler='resolve',
         help='''View a patch'''
     )
     view_parser.set_defaults(subcmd='view')
     update_parser = subparsers.add_parser(
-        'update', parents=[hash_parser, help_parser],
-        add_help=False,
+        'update', parents=[hash_parser], conflict_handler='resolve',
         help='''Update patch''',
         epilog='''Using a COMMIT-REF allows for only one ID to be specified''',
     )
@@ -497,17 +450,15 @@ def main():
     )
     update_parser.set_defaults(subcmd='update')
     list_parser = subparsers.add_parser("list",
-        add_help=False,
         #aliases=['search'],
-        parents=[filter_parser, help_parser],
+        parents=[filter_parser],
         help='''List patches, using the optional filters specified
         below and an optional substring to search for patches
         by name'''
     )
     list_parser.set_defaults(subcmd='list')
     search_parser = subparsers.add_parser("search",
-        add_help=False,
-        parents=[filter_parser, help_parser],
+        parents=[filter_parser],
         help='''Alias for "list"'''
     )
     # Poor man's argparse aliases:
-- 
2.4.1