add gainlayer command group

add GainlayerHelpFormatter

src/vban_cli/gainlayer.py

@@ -0,0 +1,51 @@
+from typing import Annotated
+
+from cyclopts import App, Argument, Parameter
+
+from . import console
+from .context import Context
+from .help import GainlayerHelpFormatter
+
+app = App(name='gainlayer', help_formatter=GainlayerHelpFormatter())
+
+
+@app.meta.default
+def launcher(
+    gainlayer_index: Annotated[int, Argument()] = None,
+    *tokens: Annotated[str, Parameter(show=False, allow_leading_hyphen=True)],
+    index: Annotated[int, Argument()] = None,
+    ctx: Annotated[Context, Parameter(show=False)] = None,
+):
+    """Control the gainlayers."""
+    additional_kwargs = {}
+    command, bound, _ = app.parse_args(tokens)
+    if index is not None and gainlayer_index is not None:
+        additional_kwargs['strip_index'] = index
+        additional_kwargs['gainlayer_index'] = gainlayer_index
+    else:
+        raise ValueError('Both gainlayer_index and index must be provided.')
+    if ctx is not None:
+        additional_kwargs['ctx'] = ctx
+
+    return command(*bound.args, **bound.kwargs, **additional_kwargs)
+
+
+@app.command(name='level')
+def level(
+    new_level: Annotated[float, Argument()] = None,
+    *,
+    strip_index: Annotated[int, Parameter(show=False)] = None,
+    gainlayer_index: Annotated[int, Parameter(show=False)] = None,
+    ctx: Annotated[Context, Parameter(show=False)] = None,
+):
+    """Get or set the level of the specified gainlayer.
+
+    Parameters
+    ----------
+    new_level : float
+        If provided, sets the level to this value. If not provided, the current level is printed.
+    """
+    if new_level is None:
+        console.out.print(ctx.client.strip[strip_index].gainlayer[gainlayer_index].gain)
+        return
+    ctx.client.strip[strip_index].gainlayer[gainlayer_index].gain = new_level