feat: add microphone selection utils

Providing two functions, one to choose the default microphone, the other to choose a microphone interactively. With tests.

ref: N25B-119

src/robot_interface/utils/microphone.py

@@ -0,0 +1,54 @@
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def choose_mic_interactive(audio):
+    """
+    Choose a microphone to use, interactively in the CLI.
+
+    :param audio: An instance of PyAudio to use.
+    :type audio: pyaudio.PyAudio
+
+    :return: A dictionary from PyAudio containing information about the microphone to use, or None
+    if there is no microphone.
+    :rtype: dict | None
+    """
+    device_count = audio.get_device_count()
+    if device_count == 0: return None
+
+    print("Found {} audio devices:".format(device_count))
+    for i in range(device_count):
+        print("- {}: {}".format(i, audio.get_device_info_by_index(i)["name"]))
+
+    microphone_index = None
+    while microphone_index is None:
+        chosen = raw_input("Which device would you like to use?\n> ")
+        try:
+            chosen = int(chosen)
+            if chosen < 0 or chosen >= device_count: raise ValueError()
+            microphone_index = chosen
+        except ValueError:
+            print("Please enter a number between 0 and {}".format(device_count-1))
+
+    chosen_microphone = audio.get_device_info_by_index(microphone_index)
+    logger.info("Chose microphone \"{}\"".format(chosen_microphone["name"]))
+    return chosen_microphone
+
+
+def choose_mic_default(audio):
+    """
+    Get the system's default microphone to use.
+
+    :param audio: An instance of PyAudio to use.
+    :type audio: pyaudio.PyAudio
+
+    :return: A dictionary from PyAudio containing information about the microphone to use, or None
+    if there is no microphone.
+    :rtype: dict | None
+    """
+    device_count = audio.get_device_count()
+    if device_count == 0: return None
+
+    default_device = audio.get_default_input_device_info()
+    return default_device