QMK CLI and JSON keymap support (#6176)

* Script to generate keymap.c from JSON file.

* Support for keymap.json

* Add a warning about the keymap.c getting overwritten.

* Fix keymap generating

* Install the python deps

* Flesh out more of the python environment

* Remove defunct json2keymap

* Style everything with yapf

* Polish up python support

* Hide json keymap.c into the .build dir

* Polish up qmk-compile-json

* Make milc work with positional arguments

* Fix a couple small things

* Fix some errors and make the CLI more understandable

* Make the qmk wrapper more robust

* Add basic QMK Doctor

* Clean up docstrings and flesh them out as needed

* remove unused compile_firmware() function

lib/python/qmk/cli/json/keymap.py

@@ -0,0 +1,54 @@
+"""Generate a keymap.c from a configurator export.
+"""
+import json
+import os
+import sys
+
+from milc import cli
+
+import qmk.keymap
+
+
+@cli.argument('-o', '--output', help='File to write to')
+@cli.argument('filename', help='Configurator JSON file')
+@cli.entrypoint('Create a keymap.c from a QMK Configurator export.')
+def main(cli):
+    """Generate a keymap.c from a configurator export.
+
+    This command uses the `qmk.keymap` module to generate a keymap.c from a configurator export. The generated keymap is written to stdout, or to a file if -o is provided.
+    """
+    # Error checking
+    if cli.args.filename == ('-'):
+        cli.log.error('Reading from STDIN is not (yet) supported.')
+        cli.print_usage()
+        exit(1)
+    if not os.path.exists(qmk.path.normpath(cli.args.filename)):
+        cli.log.error('JSON file does not exist!')
+        cli.print_usage()
+        exit(1)
+
+    # Environment processing
+    if cli.args.output == ('-'):
+        cli.args.output = None
+
+    # Parse the configurator json
+    with open(qmk.path.normpath(cli.args.filename), 'r') as fd:
+        user_keymap = json.load(fd)
+
+    # Generate the keymap
+    keymap_c = qmk.keymap.generate(user_keymap['keyboard'], user_keymap['layout'], user_keymap['layers'])
+
+    if cli.args.output:
+        output_dir = os.path.dirname(cli.args.output)
+
+        if not os.path.exists(output_dir):
+            os.makedirs(output_dir)
+
+        output_file = qmk.path.normpath(cli.args.output)
+        with open(output_file, 'w') as keymap_fd:
+            keymap_fd.write(keymap_c)
+
+        cli.log.info('Wrote keymap to %s.', cli.args.output)
+
+    else:
+        print(keymap_c)