feat: add Gallery TUI for interactive configuration and generation

- Implemented a terminal user interface (TUI) for configuring the gallery generator using Textual.
- Included functionality to manage sources with add/remove
- Integrated a log pane to display generation output from subprocess calls.
- Implemented save functionality to persist configuration changes.

gallery/cli.py

@@ -14,7 +14,10 @@ from pathlib import Path
 import argcomplete
 
 from gallery import generate
-from gallery.config import ConfigManager, GalleryConfig, GallerySource, default_config_path
+from gallery.config import (
+    ConfigManager, GalleryConfig, GallerySource,
+    default_config_path, get_active_config_path, ensure_user_config,
+)
 
 _WELCOME = """\
 Gallery - Scientific Plot Gallery Generator
@@ -67,7 +70,7 @@ def _is_configured(config_path: Path) -> bool:
 def _source_names(prefix, parsed_args, **kwargs):
     """Autocomplete helper: return configured source names."""
     try:
-        config_path = Path(parsed_args.config) if getattr(parsed_args, "config", None) else default_config_path()
+        config_path = Path(parsed_args.config) if getattr(parsed_args, "config", None) else get_active_config_path()
         return [s["name"] for s in ConfigManager(config_path).list_sources()]
     except Exception:
         return []
@@ -76,7 +79,7 @@ def _source_names(prefix, parsed_args, **kwargs):
 def _config_keys(prefix, parsed_args, **kwargs):
     """Autocomplete helper: return known dot-notation config keys."""
     try:
-        config_path = Path(parsed_args.config) if getattr(parsed_args, "config", None) else default_config_path()
+        config_path = Path(parsed_args.config) if getattr(parsed_args, "config", None) else get_active_config_path()
         data = ConfigManager(config_path).list_all()
         keys = []
         for section, values in data.items():
@@ -94,6 +97,7 @@ def _config_keys(prefix, parsed_args, **kwargs):
 # Parser construction  (separated so TUI can reuse the structure)
 # ---------------------------------------------------------------------------
 
+
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         prog="gallery",
@@ -135,6 +139,7 @@ def build_parser() -> argparse.ArgumentParser:
     cfg_sub = cfg.add_subparsers(dest="action", metavar="ACTION")
 
     sub.add_parser("install-completion", help="Install shell tab-completion (bash/zsh)")
+    sub.add_parser("tui", help="Launch the interactive TUI")
 
     cfg_sub.add_parser("list", help="Print all config values")
     cfg_sub.add_parser("path", help="Print the resolved config file path")
@@ -149,8 +154,9 @@ def build_parser() -> argparse.ArgumentParser:
 
     p_add = cfg_sub.add_parser("add-source", help="Add a plot source")
     p_add.add_argument("--name", default=None, help="Source name (default: bottom-level directory name)")
-    p_add.add_argument("--path", required=True, metavar="DIR",
-                       help="Path to source directory").completer = argcomplete.completers.DirectoriesCompleter()
+    p_add.add_argument("--path", required=True, metavar="DIR", help="Path to source directory").completer = (
+        argcomplete.completers.DirectoriesCompleter()
+    )
 
     p_rm = cfg_sub.add_parser("remove-source", help="Remove a plot source by name")
     p_rm.add_argument("name", help="Source name to remove").completer = _source_names
@@ -162,8 +168,9 @@ def build_parser() -> argparse.ArgumentParser:
 # Command handlers
 # ---------------------------------------------------------------------------
 
+
 def _run_generate(args: argparse.Namespace) -> int:
-    config_path = Path(args.config) if args.config else default_config_path()
+    config_path = Path(args.config) if args.config else get_active_config_path()
     try:
         config = GalleryConfig.from_yaml(config_path)
 
@@ -179,8 +186,12 @@ def _run_generate(args: argparse.Namespace) -> int:
             else:
                 source_to_update = matching
 
-        success = generate(config=config, clean_first=args.clean, verbose=args.verbose,
-                           source_to_update=source_to_update)
+        success = generate(
+            config=config,
+            clean_first=args.clean,
+            verbose=args.verbose,
+            source_to_update=source_to_update,
+        )
         return 0 if success else 1
 
     except (FileNotFoundError, ValueError) as e:
@@ -192,7 +203,13 @@ def _run_generate(args: argparse.Namespace) -> int:
 
 
 def _run_config(args: argparse.Namespace) -> int:
-    config_path = Path(args.config) if args.config else default_config_path()
+    if args.config:
+        config_path = Path(args.config)
+    elif args.action in ("set", "add-source", "remove-source"):
+        # Writes go to the user config; create it from the template if needed
+        config_path = ensure_user_config()
+    else:
+        config_path = get_active_config_path()
     mgr = ConfigManager(config_path)
 
     if args.action == "path":
@@ -200,6 +217,7 @@ def _run_config(args: argparse.Namespace) -> int:
 
     elif args.action == "list":
         import yaml
+
         print(yaml.dump(mgr.list_all(), default_flow_style=False).rstrip())
 
     elif args.action == "sources":
@@ -280,6 +298,7 @@ def _run_install_completion() -> int:
 # Entry point
 # ---------------------------------------------------------------------------
 
+
 def main():
     parser = build_parser()
     argcomplete.autocomplete(parser)  # no-op when not completing; exits during completion
@@ -291,8 +310,13 @@ def main():
         sys.exit(_run_config(args))
     elif args.command == "install-completion":
         sys.exit(_run_install_completion())
+    elif args.command == "tui":
+        from gallery.tui import GalleryTUI
+        config_path = Path(args.config) if args.config else None
+        GalleryTUI(config_path=config_path).run()
+        sys.exit(0)
     else:
-        print(_WELCOME.format(config_path=default_config_path()))
+        print(_WELCOME.format(config_path=get_active_config_path()))
         sys.exit(0)