Improve argument handling of c2json (#22170)

* Improve argument handling of c2json

* Add automagic

3 files changed, 46 insertions, 42 deletions

diff --git a/lib/python/qmk/cli/c2json.py b/lib/python/qmk/cli/c2json.py
index 7f6aca070a..f7f1f2ffba 100644
--- a/lib/python/qmk/cli/c2json.py
+++ b/lib/python/qmk/cli/c2json.py
@@ -1,45 +1,57 @@
 """Generate a keymap.json from a keymap.c file.
 """
+import re
 import json
 
 from argcomplete.completers import FilesCompleter
 from milc import cli
 
-import qmk.keymap
 import qmk.path
 from qmk.json_encoders import InfoJSONEncoder
+from qmk.decorators import automagic_keyboard, automagic_keymap
 from qmk.keyboard import keyboard_completer, keyboard_folder
+from qmk.keymap import locate_keymap, find_keymap_from_dir, generate_json, c2json as c2json_impl
 from qmk.errors import CppError
+from qmk.commands import dump_lines
 
 
 @cli.argument('--no-cpp', arg_only=True, action='store_false', help='Do not use \'cpp\' on keymap.c')
 @cli.argument('-o', '--output', arg_only=True, type=qmk.path.normpath, help='File to write to')
 @cli.argument('-q', '--quiet', arg_only=True, action='store_true', help="Quiet mode, only output error messages")
-@cli.argument('-kb', '--keyboard', arg_only=True, type=keyboard_folder, completer=keyboard_completer, required=True, help='The keyboard\'s name')
-@cli.argument('-km', '--keymap', arg_only=True, required=True, help='The keymap\'s name')
-@cli.argument('filename', arg_only=True, completer=FilesCompleter('.c'), help='keymap.c file')
+@cli.argument('-kb', '--keyboard', type=keyboard_folder, completer=keyboard_completer, help='The keyboard\'s name')
+@cli.argument('-km', '--keymap', help='The keymap\'s name')
+@cli.argument('filename', nargs='?', type=qmk.path.FileType('r'), arg_only=True, completer=FilesCompleter('.c'), help='keymap.c file')
 @cli.subcommand('Creates a keymap.json from a keymap.c file.')
+@automagic_keyboard
+@automagic_keymap
 def c2json(cli):
     """Generate a keymap.json from a keymap.c file.
 
     This command uses the `qmk.keymap` module to generate a keymap.json from a keymap.c file. The generated keymap is written to stdout, or to a file if -o is provided.
     """
-    if cli.args.filename != '-':
-        cli.args.filename = qmk.path.normpath(cli.args.filename)
+    filename = cli.args.filename
+    keyboard = cli.config.c2json.keyboard
+    keymap = cli.config.c2json.keymap
 
-        # Error checking
-        if not cli.args.filename.exists():
-            cli.log.error('C file does not exist!')
-            cli.print_usage()
-            return False
+    if filename:
+        if not keyboard and not keymap:
+            # fallback to inferring keyboard/keymap from path
+            (keymap, found_type) = find_keymap_from_dir(filename)
+            if found_type == 'keymap_directory':
+                keyboard = re.search(fr"keyboards/(.+)/keymaps/{keymap}/.*", filename.as_posix()).group(1)
 
-    # Environment processing
-    if cli.args.output == ('-'):
-        cli.args.output = None
+    elif keyboard and keymap:
+        if not filename:
+            # fallback to inferring keyboard/keymap from path
+            filename = locate_keymap(keyboard, keymap)
+
+    if not all((filename, keyboard, keymap)):
+        cli.log.error('You must supply keyboard and keymap, a path to a keymap.c within qmk_firmware, or absolute filename and keyboard and keymap')
+        cli.print_help()
+        return False
 
-    # Parse the keymap.c
     try:
-        keymap_json = qmk.keymap.c2json(cli.args.keyboard, cli.args.keymap, cli.args.filename, use_cpp=cli.args.no_cpp)
+        keymap_json = c2json_impl(keyboard, keymap, filename, use_cpp=cli.args.no_cpp)
     except CppError as e:
         if cli.config.general.verbose:
             cli.log.debug('The C pre-processor ran into a fatal error: %s', e)
@@ -48,19 +60,14 @@ def c2json(cli):
 
     # Generate the keymap.json
     try:
-        keymap_json = qmk.keymap.generate_json(keymap_json['keymap'], keymap_json['keyboard'], keymap_json['layout'], keymap_json['layers'])
+        keymap_json = generate_json(keymap_json['keymap'], keymap_json['keyboard'], keymap_json['layout'], keymap_json['layers'])
     except KeyError:
         cli.log.error('Something went wrong. Try to use --no-cpp.')
         return False
 
     if cli.args.output:
-        cli.args.output.parent.mkdir(parents=True, exist_ok=True)
-        if cli.args.output.exists():
-            cli.args.output.replace(cli.args.output.parent / (cli.args.output.name + '.bak'))
-        cli.args.output.write_text(json.dumps(keymap_json, cls=InfoJSONEncoder, sort_keys=True))
-
-        if not cli.args.quiet:
-            cli.log.info('Wrote keymap to %s.', cli.args.output)
-
+        keymap_lines = [json.dumps(keymap_json, cls=InfoJSONEncoder, sort_keys=True)]
     else:
-        print(json.dumps(keymap_json))
+        keymap_lines = [json.dumps(keymap_json)]
+
+    dump_lines(cli.args.output, keymap_lines, cli.args.quiet)
diff --git a/lib/python/qmk/keymap.py b/lib/python/qmk/keymap.py
index 11e8d39dad..281c53cfda 100644
--- a/lib/python/qmk/keymap.py
+++ b/lib/python/qmk/keymap.py
@@ -191,16 +191,15 @@ def _strip_any(keycode):
     return keycode
 
 
-def find_keymap_from_dir():
-    """Returns `(keymap_name, source)` for the directory we're currently in.
-
+def find_keymap_from_dir(*args):
+    """Returns `(keymap_name, source)` for the directory provided (or cwd if not specified).
     """
-    relative_cwd = qmk.path.under_qmk_firmware()
+    relative_path = qmk.path.under_qmk_firmware(*args)
 
-    if relative_cwd and len(relative_cwd.parts) > 1:
+    if relative_path and len(relative_path.parts) > 1:
         # If we're in `qmk_firmware/keyboards` and `keymaps` is in our path, try to find the keyboard name.
-        if relative_cwd.parts[0] == 'keyboards' and 'keymaps' in relative_cwd.parts:
-            current_path = Path('/'.join(relative_cwd.parts[1:]))  # Strip 'keyboards' from the front
+        if relative_path.parts[0] == 'keyboards' and 'keymaps' in relative_path.parts:
+            current_path = Path('/'.join(relative_path.parts[1:]))  # Strip 'keyboards' from the front
 
             if 'keymaps' in current_path.parts and current_path.name != 'keymaps':
                 while current_path.parent.name != 'keymaps':
@@ -209,13 +208,13 @@ def find_keymap_from_dir():
                 return current_path.name, 'keymap_directory'
 
         # If we're in `qmk_firmware/layouts` guess the name from the community keymap they're in
-        elif relative_cwd.parts[0] == 'layouts' and is_keymap_dir(relative_cwd):
-            return relative_cwd.name, 'layouts_directory'
+        elif relative_path.parts[0] == 'layouts' and is_keymap_dir(relative_path):
+            return relative_path.name, 'layouts_directory'
 
         # If we're in `qmk_firmware/users` guess the name from the userspace they're in
-        elif relative_cwd.parts[0] == 'users':
+        elif relative_path.parts[0] == 'users':
             # Guess the keymap name based on which userspace they're in
-            return relative_cwd.parts[1], 'users_directory'
+            return relative_path.parts[1], 'users_directory'
 
     return None, None
 
@@ -657,7 +656,7 @@ def parse_keymap_c(keymap_file, use_cpp=True):
     Returns:
         a dictionary containing the parsed keymap
     """
-    if keymap_file == '-':
+    if not isinstance(keymap_file, (Path, str)) or keymap_file == '-':
         if use_cpp:
             keymap_file = _c_preprocess(None, sys.stdin)
         else:
diff --git a/lib/python/qmk/path.py b/lib/python/qmk/path.py
index 9d248451b8..94582a05e0 100644
--- a/lib/python/qmk/path.py
+++ b/lib/python/qmk/path.py
@@ -19,13 +19,11 @@ def is_keyboard(keyboard_name):
         return rules_mk.exists()
 
 
-def under_qmk_firmware():
+def under_qmk_firmware(path=Path(os.environ['ORIG_CWD'])):
     """Returns a Path object representing the relative path under qmk_firmware, or None.
     """
-    cwd = Path(os.environ['ORIG_CWD'])
-
     try:
-        return cwd.relative_to(QMK_FIRMWARE)
+        return path.relative_to(QMK_FIRMWARE)
     except ValueError:
         return None