Start with generic negromate command with entry points for other modules

negromate/songs/commands/__init__.py

@@ -0,0 +1,71 @@
+import argparse
+import sys
+try:
+    from importlib import metadata
+except ImportError:  # Python <3.8
+    import importlib_metadata as metadata
+
+
+def main():
+    """
+        Build parser for all the commands and launch appropiate command.
+
+        Each command must be a module with at least the following members:
+
+            * name: String with the command name. Will be used for
+              argparse subcommand.
+            * help_text: String with the help text.
+            * options: Function to build the parser of the command. Takes
+              one parametter, the argparser parser instance for this
+              subcommand.
+            * run: Function that runs the actual command. Takes one
+              parametter, the Namespace with the arguments.
+
+        Minimal module example:
+
+            # hello_world.py
+            name = 'hello'
+            help_text = 'Sample command'
+
+            def options(parser):
+                parser.add_argument(
+                    '-w', '--who', default='World'
+                    help="Who to say hello, defaults to 'World'"
+                )
+
+            def run(args):
+                print("Hello {}".format(args.who))
+
+        To add more commands to negromate register 'negromate.commands'
+        entry point in setup.cfg. For example:
+
+            [options.entry_points]
+                negromate.commands =
+                    hello = negromate.web.commands.hello_world
+
+    """
+    commands = []
+    # clean sys.argv for any module imported here
+    # Yes Kivy, I'm looking at you
+    args = sys.argv.copy()
+    sys.argv = args[:1]
+
+    entry_points = metadata.entry_points().get('negromate.commands', [])
+    for entry_point in entry_points:
+        commands.append(entry_point.load())
+
+    parser = argparse.ArgumentParser()
+    parser.set_defaults(command=None)
+    subparsers = parser.add_subparsers()
+    for command in commands:
+        command_parser = subparsers.add_parser(command.name, help=command.help_text)
+        command_parser.set_defaults(command=command.name)
+        command.options(command_parser)
+
+    args = parser.parse_args(args[1:])
+    if args.command is None:
+        parser.print_usage()
+    else:
+        for command in commands:
+            if args.command == command.name:
+                command.run(args)

negromate/songs/commands/songs.py

@@ -1,11 +1,20 @@
 import sys
 from pathlib import Path
 
-from .loader import load_songs
+from ..loader import load_songs
+
+name = 'songs'
+help_text = 'Update song database'
 
 
-def main():
-    songs, pending_songs = load_songs(Path(sys.argv[1]))
+def options(parser):
+    parser.add_argument(
+        'song_folder', type=Path,
+        help="Folder with the song database.")
+
+
+def run(args):
+    songs, pending_songs = load_songs(args.song_folder)
     print(
         "#######\n"
         " Songs\n"

negromate/songs/commands/thumbnail.py

@@ -0,0 +1,22 @@
+from pathlib import Path
+
+from negromate.songs.utils import generate_cover, generate_thumbnail
+
+name = 'thumbnail'
+help_text = 'Generate cover and thumbnail for a video.'
+
+
+def options(parser):
+    parser.add_argument(
+        'video', help="Video of the song.", type=Path)
+    parser.add_argument(
+        'second', type=int,
+        help='Take snapshot at this second.')
+
+
+def run(args):
+    video = args.video
+    cover = video.parent / 'cover.jpg'
+    thumbnail = video.parent / 'thumb.jpg'
+    generate_cover(video, cover, args.second)
+    generate_thumbnail(cover, thumbnail)

setup.cfg

@@ -22,13 +22,17 @@ packages = find:
 zip_safe = true
 python_requires = >= 3.4
 install_requires =
+    importlib_metadata
     webvtt-py
     asstosrt ==0.1.6
     srt  ==1.6.0
 
 [options.entry_points]
 console_scripts =
-    negromate-songs = negromate.songs.command:main
+    negromate = negromate.songs.commands:main
+negromate.commands =
+    songs = negromate.songs.commands.songs
+    thumbnail = negromate.songs.commands.thumbnail
 
 [bdist_wheel]
 # This flag says to generate wheels that support both Python 2 and Python