Add --video_list, --channel_list listargs to improve ergonomics.

This reduces the need to pipe two ycli processes together, which
makes commands easier to type and avoids opening two connections
to the same database.

frontends/ycdl_cli.py

@@ -18,6 +18,40 @@ log = vlogging.getLogger(__name__, 'ycdl_cli')
 def closest_db():
     return ycdl.ycdldb.YCDLDB.closest_ycdldb()
 
+def get_channels_from_args(args):
+    '''
+    This function unifies channel IDs that are part of the command's argparser
+    and channels that come from --channel_list listargs into a single stream
+    of Channel objects.
+    '''
+    ycdldb = closest_db()
+    channels = []
+
+    if args.channel_list_args:
+        channels.extend(_channel_list_argparse(args.channel_list_args))
+
+    if args.channel_ids:
+        channels.extend(ycdldb.get_channels_by_id(pipeable.input_many(args.channel_ids)))
+
+    return channels
+
+def get_videos_from_args(args):
+    '''
+    This function unifies video IDs that are part of the command's argparser
+    and videos that come from --video_list listargs into a single stream
+    of Video objects.
+    '''
+    ycdldb = closest_db()
+    videos = []
+
+    if args.video_list_args:
+        videos.extend(_video_list_argparse(args.video_list_args))
+
+    if args.video_ids:
+        videos.extend(ycdldb.get_videos_by_id(pipeable.input_many(args.video_ids)))
+
+    return videos
+
 # ARGPARSE #########################################################################################
 
 def add_channel_argparse(args):
@@ -36,10 +70,13 @@ def add_channel_argparse(args):
 
     return 0
 
-def channel_list_argparse(args):
+def _channel_list_argparse(args):
     ycdldb = closest_db()
     channels = sorted(ycdldb.get_channels(), key=lambda c: c.name.lower())
-    for channel in channels:
+    yield from channels
+
+def channel_list_argparse(args):
+    for channel in _channel_list_argparse(args):
         line = args.format.format(
             automark=channel.automark,
             autorefresh=channel.autorefresh,
@@ -54,9 +91,11 @@ def channel_list_argparse(args):
 
 def delete_channel_argparse(args):
     ycdldb = closest_db()
-    for channel_id in pipeable.input_many(args.channel_ids):
+    needs_commit = False
-        channel = ycdldb.get_channel(channel_id)
+
+    for channel in get_channels_from_args(args):
         channel.delete()
+        needs_commit = True
 
     if args.autoyes or interactive.getpermission('Commit?'):
         ycdldb.commit()
@@ -66,8 +105,8 @@ def delete_channel_argparse(args):
 def download_video_argparse(args):
     ycdldb = closest_db()
     needs_commit = False
-    for video_id in pipeable.input_many(args.video_ids):
+
-        video = ycdldb.get_video(video_id)
+    for video in get_videos_from_args(args):
         queuefile = ycdldb.download_video(
             video,
             download_directory=args.download_directory,
@@ -117,14 +156,17 @@ def refresh_channels_argparse(args):
 
     return status
 
-def video_list_argparse(args):
+def _video_list_argparse(args):
     ycdldb = closest_db()
     videos = ycdldb.get_videos(channel_id=args.channel_id, state=args.state, orderby=args.orderby)
 
     if args.limit is not None:
         videos = itertools.islice(videos, args.limit)
 
-    for video in videos:
+    yield from videos
+
+def video_list_argparse(args):
+    for video in _video_list_argparse(args):
         line = args.format.format(
             author_id=video.author_id,
             duration=video.duration,
@@ -207,9 +249,12 @@ channel_list:
         The available attributes are id, name, automark, autorefresh,
         uploads_playlist, queuefile_extension.
 
+        If you are using --channel_list as listargs for another command, then
+        this argument is not relevant.
+
     > ycdl_cli.py channel_list
 
-    Example:
+    Examples:
     > ycdl_cli.py channel_list
     > ycdl_cli.py channel_list --format "{id} automark={automark}"
 ''',
@@ -222,11 +267,19 @@ delete_channel:
     Uses pipeable to support !c clipboard, !i stdin.
 
     > ycdl_cli.py delete_channel channel_id [channel_id channel_id...]
+    > ycdl_cli.py delete_channel --channel_list listargs
 
     Examples:
+    # Delete one channel
     > ycdl_cli.py delete_channel UCOYBuFGi8T3NM5fNAptCLCw
+
+    # Delete many channels
     > ycdl_cli.py delete_channel UCOYBuFGi8T3NM5fNAptCLCw UCmu9PVIZBk-ZCi-Sk2F2utA
-    > ycdl_cli.py channel_list --format {id} | ycdl_cli.py delete_channel !i --yes
+
+    # Delete all channels in the database
+    > ycdl_cli.py delete_channel --channel-list
+
+    See ycdl_cli.py channel_list --help for help with listargs.
 ''',
 
 download_video='''
@@ -240,6 +293,7 @@ download_video:
     Uses pipeable to support !c clipboard, !i stdin.
 
     > ycdl_cli.py download_video video_id [video_id video_id...] <flags>
+    > ycdl_cli.py download_video <flags> --video_list listargs
 
     flags:
     --download_directory X:
@@ -258,9 +312,19 @@ download_video:
         config file. You can pass this argument to override both of those.
 
     Examples:
+    # Download one video
     > ycdl_cli.py download_video thOifuHs6eY
+
+    # Force download many videos
     > ycdl_cli.py download_video yJ-oASr_djo vHuFizITMdA --force
-    > ycdl_cli.py video_list --channel UCvBv3PCvD9v-IKKTkd94XPg | ycdl_cli.py download_video !i --yes
+
+    # Download all videos from this channel
+    > ycdl_cli.py download_video --video_list --channel UCvBv3PCvD9v-IKKTkd94XPg
+
+    # Force re-download all videos that have already been downloaded
+    > ycdl_cli.py download_video --force --video_list --state downloaded
+
+    See ycdl_cli.py video_list --help for help with listargs.
 ''',
 
 init='''
@@ -336,6 +400,20 @@ def main(argv):
     parser = argparse.ArgumentParser(description=__doc__)
     subparsers = parser.add_subparsers()
 
+    primary_args = []
+    video_list_args = []
+    channel_list_args = []
+    mode = primary_args
+    for arg in argv:
+        if 0:
+            pass
+        elif arg in {'--channel_list', '--channel-list'}:
+            mode = channel_list_args
+        elif arg in {'--video_list', '--video-list'}:
+            mode = video_list_args
+        else:
+            mode.append(arg)
+
     p_add_channel = subparsers.add_parser('add_channel', aliases=['add-channel'])
     p_add_channel.add_argument('channel_id')
     p_add_channel.add_argument('--automark', default='pending')
@@ -351,12 +429,12 @@ def main(argv):
     p_channel_list.set_defaults(func=channel_list_argparse)
 
     p_delete_channel = subparsers.add_parser('delete_channel', aliases=['delete-channel'])
-    p_delete_channel.add_argument('channel_ids', nargs='+')
+    p_delete_channel.add_argument('channel_ids', nargs='*')
     p_delete_channel.add_argument('--yes', dest='autoyes', action='store_true')
     p_delete_channel.set_defaults(func=delete_channel_argparse)
 
     p_download_video = subparsers.add_parser('download_video', aliases=['download-video'])
-    p_download_video.add_argument('video_ids', nargs='+')
+    p_download_video.add_argument('video_ids', nargs='*')
     p_download_video.add_argument('--download_directory', '--download-directory', default=None)
     p_download_video.add_argument('--force', action='store_true')
     p_download_video.add_argument('--queuefile_extension', '--queuefile-extension', default=None)
@@ -380,8 +458,21 @@ def main(argv):
     p_video_list.add_argument('--state', default=None)
     p_video_list.set_defaults(func=video_list_argparse)
 
+    ##
+
+    def postprocessor(args):
+        args.video_list_args = p_video_list.parse_args(video_list_args)
+        args.channel_list_args = p_channel_list.parse_args(channel_list_args)
+        return args
+
     try:
-        return betterhelp.subparser_main(argv, parser, DOCSTRING, SUB_DOCSTRINGS)
+        return betterhelp.subparser_main(
+            primary_args,
+            parser,
+            main_docstring=DOCSTRING,
+            sub_docstrings=SUB_DOCSTRINGS,
+            args_postprocessor=postprocessor,
+        )
     except ycdl.exceptions.NoClosestYCDLDB as exc:
         pipeable.stderr(exc.error_message)
         pipeable.stderr('Try `ycdl_cli.py init` to create the database.')