Work on cli

src/anemoi/utils/cli.py

@@ -0,0 +1,126 @@
+# (C) Copyright 2024 European Centre for Medium-Range Weather Forecasts.
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+import argparse
+import importlib
+import logging
+import os
+import sys
+import traceback
+
+LOG = logging.getLogger(__name__)
+
+
+class Command:
+    def run(self, args):
+        raise NotImplementedError(f"Command not implemented: {args.command}")
+
+
+def make_parser(description, commands):
+    parser = argparse.ArgumentParser(
+        description=description,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+
+    parser.add_argument(
+        "--version",
+        "-V",
+        action="store_true",
+        help="show the version and exit",
+    )
+    parser.add_argument(
+        "--debug",
+        "-d",
+        action="store_true",
+        help="Debug mode",
+    )
+
+    subparsers = parser.add_subparsers(help="commands:", dest="command")
+    for name, command in commands.items():
+        command_parser = subparsers.add_parser(name, help=command.__doc__)
+        command.add_arguments(command_parser)
+
+    return parser
+
+
+class Failed(Command):
+    def __init__(self, name, error):
+        self.name = name
+        self.error = error
+
+    def add_arguments(self, command_parser):
+        command_parser.add_argument("x", nargs=argparse.REMAINDER)
+
+    def run(self, args):
+        print(f"Command '{self.name}' not available: {self.error}")
+        sys.exit(1)
+
+
+def register_commands(here, package, select, fail=None):
+    result = {}
+    not_available = {}
+
+    for p in os.listdir(here):
+        full = os.path.join(here, p)
+        if p.startswith("_"):
+            continue
+        if not (p.endswith(".py") or (os.path.isdir(full) and os.path.exists(os.path.join(full, "__init__.py")))):
+            continue
+
+        name, _ = os.path.splitext(p)
+
+        try:
+            imported = importlib.import_module(
+                f".{name}",
+                package=package,
+            )
+        except ImportError as e:
+            not_available[name] = e
+            continue
+
+        obj = select(imported)
+        if obj is not None:
+            result[name] = obj
+
+    for name, e in not_available.items():
+        if fail is None:
+            pass
+        if callable(fail):
+            result[name] = fail(name, e)
+
+    return result
+
+
+def cli_main(version, description, commands):
+    parser = make_parser(description, commands)
+    args = parser.parse_args()
+
+    if args.version:
+        print(version)
+        return
+
+    if args.command is None:
+        parser.print_help()
+        return
+
+    cmd = commands[args.command]
+
+    logging.basicConfig(
+        format="%(asctime)s %(levelname)s %(message)s",
+        datefmt="%Y-%m-%d %H:%M:%S",
+        level=logging.DEBUG if args.debug else logging.INFO,
+    )
+
+    try:
+        cmd.run(args)
+    except ValueError as e:
+        traceback.print_exc()
+        LOG.error("\n💣 %s", str(e).lstrip())
+        LOG.error("💣 Exiting")
+        sys.exit(1)
+
+    sys.exit(0)