Add support for parsing config.toml from config dir

Initially this just supports a single config key,
calendars.default-calendar.

MANIFEST.in

@@ -2,5 +2,6 @@ include ChangeLog
 include README.md
 exclude .git*
 
+graft data
 graft docs
 prune .github

data/config-schema.json

@@ -0,0 +1,19 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "gcalcli config",
+  "type": "object",
+  "description": "User configuration for gcalcli command-line tool. See https://pypi.org/project/gcalcli/.",
+  "properties": {
+    "calendars": {
+      "type": "object",
+      "description": "Settings about the set of calendars gcalcli operates on",
+      "properties": {
+        "default-calendar": {
+          "type": "array",
+          "items": { "type": "string" },
+          "description": "Calendar(s) to use as default for certain commands when no explicit target calendar is otherwise specified"
+        }
+      }
+    }
+  }
+}

gcalcli/argparsers.py

@@ -4,17 +4,15 @@
 import copy as _copy
 import datetime
 import locale
-import os
 import pathlib
 import sys
 from shutil import get_terminal_size
 
 import argcomplete  # type: ignore
-import platformdirs
 
 import gcalcli
 
-from . import utils
+from . import env, utils
 from .deprecations import DeprecatedStoreTrue, parser_allow_deprecated
 from .details import DETAILS
 from .printer import valid_color_name
@@ -35,7 +33,7 @@
         'is no longer supported.',
     },
     '--config-folder': {
-        'default': os.environ.get('GCALCLI_CONFIG'),
+        'default': env.default_config_dir(),
         'type': pathlib.Path,
         'help': 'Optional directory used to load config files. Deprecated: '
         'prefer $GCALCLI_CONFIG.',
@@ -312,9 +310,7 @@ class RawDescArgDefaultsHelpFormatter(
 
 @parser_allow_deprecated(name='program')
 def get_argument_parser():
-    config_dir = (
-        os.environ.get('GCALCLI_CONFIG') or platformdirs.user_config_dir()
-    )
+    config_dir = env.default_config_dir()
     rc_paths = [pathlib.Path(config_dir).joinpath('gcalclirc')]
     legacy_rc_path = pathlib.Path.home().joinpath('.gcalclirc')
     if legacy_rc_path.exists():

gcalcli/cli.py

@@ -24,9 +24,12 @@
 import os
 import signal
 import sys
+import tomllib
+
+import argparse
 import truststore
 
-from . import utils
+from . import env, utils
 from .argparsers import get_argument_parser, handle_unparsed
 from .exceptions import GcalcliError
 from .gcal import GoogleCalendarInterface
@@ -86,9 +89,10 @@ def run_add_prompt(parsed_args, printer):
 
 
 def main():
-    parser = get_argument_parser()
     # import trusted certificate store to enable SSL, e.g., behind firewalls
     truststore.inject_into_ssl()
+
+    parser = get_argument_parser()
     try:
         argv = sys.argv[1:]
         gcalclirc = os.path.expanduser('~/.gcalclirc')
@@ -106,6 +110,16 @@ def main():
         parser.print_usage()
         sys.exit(1)
 
+    config_dir = env.default_config_dir()
+    config_filepath = config_dir.joinpath('config.toml')
+    opts_from_config = argparse.Namespace()
+    if config_filepath.exists():
+        with config_filepath.open('rb') as config_file:
+            config = tomllib.load(config_file)
+            opts_from_config.defaultCalendar = config.get('calendars', {}).get(
+                'default-calendar', []
+            )
+
     if parsed_args.config_folder:
         parsed_args.config_folder = parsed_args.config_folder.expanduser()
         gcalclirc_path = parsed_args.config_folder.joinpath('gcalclirc')
@@ -116,7 +130,9 @@ def main():
                 tmp_argv if parsed_args.includeRc else argv
             )
 
-        (parsed_args, unparsed) = parser.parse_known_args(tmp_argv)
+        (parsed_args, unparsed) = parser.parse_known_args(
+            tmp_argv, namespace=opts_from_config
+        )
         if parsed_args.config_folder:
             parsed_args.config_folder = parsed_args.config_folder.expanduser()
 

gcalcli/env.py

@@ -0,0 +1,16 @@
+import os
+import pathlib
+import platformdirs
+
+from . import __program__
+
+
+def default_data_dir() -> pathlib.Path:
+    return platformdirs.user_data_path(__program__)
+
+
+def default_config_dir() -> pathlib.Path:
+    return pathlib.Path(
+        os.environ.get('GCALCLI_CONFIG')
+        or platformdirs.user_config_dir(__program__)
+    )

gcalcli/gcal.py

@@ -22,9 +22,8 @@
 from dateutil.tz import tzlocal
 from googleapiclient.discovery import build
 from googleapiclient.errors import HttpError
-import platformdirs
 
-from . import __program__, actions, auth, ics, utils
+from . import actions, auth, env, ics, utils
 from ._types import Cache, CalendarListEntry, Event
 from .actions import ACTIONS
 from .conflicts import ShowConflicts
@@ -134,13 +133,9 @@ def _retry_with_backoff(self, method: googleapiclient.http.HttpRequest):
 
         return None
 
-    @staticmethod
-    def default_data_dir() -> pathlib.Path:
-        return platformdirs.user_data_path(__program__)
-
     @functools.cache
     def data_file_path(self, name: str) -> pathlib.Path:
-        path = self.default_data_dir().joinpath(name)
+        path = env.default_data_dir().joinpath(name)
         explicit_config: pathlib.Path = self.options['config_folder']
         if explicit_config:
             legacy_path = explicit_config.joinpath(name)