1 files changed, 91 insertions, 0 deletions
diff --git a/include/py/homekit/audio/amixer.py b/include/py/homekit/audio/amixer.py
new file mode 100644
index 0000000..8ed754b
--- /dev/null
+++ b/include/py/homekit/audio/amixer.py
@@ -0,0 +1,91 @@
+import subprocess
+
+from ..config import config
+from threading import Lock
+from typing import Union, List
+
+
+_lock = Lock()
+_default_step = 5
+
+
+def has_control(s: str) -> bool:
+    for control in config.app_config['amixer']['controls']:
+        if control['name'] == s:
+            return True
+    return False
+
+
+def get_caps(s: str) -> List[str]:
+    for control in config.app_config['amixer']['controls']:
+        if control['name'] == s:
+            return control['caps']
+    raise KeyError(f'control {s} not found')
+
+
+def get_all() -> list:
+    controls = []
+    for control in config.app_config['amixer']['controls']:
+        controls.append({
+            'name': control['name'],
+            'info': get(control['name']),
+            'caps': control['caps']
+        })
+    return controls
+
+
+def get(control: str):
+    return call('get', control)
+
+
+def mute(control):
+    return call('set', control, 'mute')
+
+
+def unmute(control):
+    return call('set', control, 'unmute')
+
+
+def cap(control):
+    return call('set', control, 'cap')
+
+
+def nocap(control):
+    return call('set', control, 'nocap')
+
+
+def _get_default_step() -> int:
+    if 'step' in config.app_config['amixer']:
+        return int(config.app_config['amixer']['step'])
+
+    return _default_step
+
+
+def incr(control, step=None):
+    if step is None:
+        step = _get_default_step()
+    return call('set', control, f'{step}%+')
+
+
+def decr(control, step=None):
+    if step is None:
+        step = _get_default_step()
+    return call('set', control, f'{step}%-')
+
+
+def call(*args, return_code=False) -> Union[int, str]:
+    with _lock:
+        result = subprocess.run([config.app_config['amixer']['bin'], *args],
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        if return_code:
+            return result.returncode
+
+        if result.returncode != 0:
+            raise AmixerError(result.stderr.decode().strip())
+
+        return result.stdout.decode().strip()
+
+
+class AmixerError(OSError):
+    pass