Add decorators for determining keyboard and keymap based on current directory (#8191)

* Use pathlib everywhere we can

* Improvements based on @erovia's feedback

* rework qmk compile and qmk flash to use pathlib

* style

* Remove the subcommand_name argument from find_keyboard_keymap()

* add experimental decorators

* Create decorators for finding keyboard and keymap based on current directory.

Decorators were inspired by @Erovia's brilliant work on the proof of concept.

lib/python/qmk/decorators.py

@@ -0,0 +1,85 @@
+"""Helpful decorators that subcommands can use.
+"""
+import functools
+from pathlib import Path
+
+from milc import cli
+
+from qmk.path import is_keyboard, is_keymap_dir, under_qmk_firmware
+
+
+def automagic_keyboard(func):
+    """Sets `cli.config.<subcommand>.keyboard` based on environment.
+
+    This will rewrite cli.config.<subcommand>.keyboard if the user did not pass `--keyboard` and the directory they are currently in is a keyboard or keymap directory.
+    """
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        # Check to make sure their copy of MILC supports config_source
+        if not hasattr(cli, 'config_source'):
+            cli.log.error("This subcommand requires a newer version of the QMK CLI. Please upgrade using `pip3 install --upgrade qmk` or your package manager.")
+            exit(1)
+
+        # Ensure that `--keyboard` was not passed and CWD is under `qmk_firmware/keyboards`
+        if cli.config_source[cli._entrypoint.__name__]['keyboard'] != 'argument':
+            relative_cwd = under_qmk_firmware()
+
+            if relative_cwd and len(relative_cwd.parts) > 1 and relative_cwd.parts[0] == 'keyboards':
+                # Attempt to extract the keyboard name from the current directory
+                current_path = Path('/'.join(relative_cwd.parts[1:]))
+
+                if 'keymaps' in current_path.parts:
+                    # Strip current_path of anything after `keymaps`
+                    keymap_index = len(current_path.parts) - current_path.parts.index('keymaps') - 1
+                    current_path = current_path.parents[keymap_index]
+
+                if is_keyboard(current_path):
+                    cli.config[cli._entrypoint.__name__]['keyboard'] = str(current_path)
+                    cli.config_source[cli._entrypoint.__name__]['keyboard'] = 'keyboard_directory'
+
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+def automagic_keymap(func):
+    """Sets `cli.config.<subcommand>.keymap` based on environment.
+
+    This will rewrite cli.config.<subcommand>.keymap if the user did not pass `--keymap` and the directory they are currently in is a keymap, layout, or user directory.
+    """
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        # Check to make sure their copy of MILC supports config_source
+        if not hasattr(cli, 'config_source'):
+            cli.log.error("This subcommand requires a newer version of the QMK CLI. Please upgrade using `pip3 install --upgrade qmk` or your package manager.")
+            exit(1)
+
+        # Ensure that `--keymap` was not passed and that we're under `qmk_firmware`
+        if cli.config_source[cli._entrypoint.__name__]['keymap'] != 'argument':
+            relative_cwd = under_qmk_firmware()
+
+            if relative_cwd and len(relative_cwd.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 'keymaps' in current_path.parts and current_path.name != 'keymaps':
+                        while current_path.parent.name != 'keymaps':
+                            current_path = current_path.parent
+                        cli.config[cli._entrypoint.__name__]['keymap'] = current_path.name
+                        cli.config_source[cli._entrypoint.__name__]['keyboard'] = '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):
+                    cli.config[cli._entrypoint.__name__]['keymap'] = relative_cwd.name
+                    cli.config_source[cli._entrypoint.__name__]['keyboard'] = 'layouts_directory'
+
+                # If we're in `qmk_firmware/users` guess the name from the userspace they're in
+                elif relative_cwd.parts[0] == 'users':
+                    # Guess the keymap name based on which userspace they're in
+                    cli.config[cli._entrypoint.__name__]['keymap'] = relative_cwd.parts[1]
+                    cli.config_source[cli._entrypoint.__name__]['keyboard'] = 'users_directory'
+
+        return func(*args, **kwargs)
+
+    return wrapper