wip feat(cli): add CLI tool to set output device

Summary:
Add a simple CLI tool to configure proxy audio devices.

Right now this is broken.  I'm committing it so I can ask for help.

Reproduction steps:
1. In the source code for `main.cpp:main`, change the invocation of
`select_audio_device` to be a non-proxy audio device on your system
2. In Xcode, run the `proxy-audio-device-cli` target
3. It doesn't work!! 😭

This is what's confusing me:

4. Put a breakpoint in `AudioDevice.cpp:setObjectPropertyName:329`
5. Try setting the same device through the CLI program again, and note the
parameters we call `AudioObjectSetPropertyData` with
6. Try setting the same device through the GUI, and note the paramaters we call
`AudioObjectSetPropertyData` with
7. It's the same thing!

I'm not sure why the GUI works and the CLI doesn't.  I'm hoping someone can
help me figure it out.

ProxyAudioDeviceSettings/WindowDelegate.mm

@@ -216,8 +216,10 @@ - (IBAction)outputDeviceSelected:(id)sender {
     }
 
     AudioDeviceID proxyAudioBox = AudioDevice::audioDeviceIDForBoxUID(CFSTR(kBox_UID));
+    NSString *formattedThing = [NSString stringWithFormat:@"outputDevice=%@", uid];
+    NSLog(@"%@\n", formattedThing);
     AudioDevice::setObjectName(proxyAudioBox,
-                               (__bridge_retained CFStringRef)[NSString stringWithFormat:@"outputDevice=%@", uid]);
+                               (__bridge_retained CFStringRef)formattedThing);
 }
 
 - (NSString *)currentOutputDeviceBufferFrameSize {

proxy-audio-device-cli/main.cpp

@@ -0,0 +1,132 @@
+//
+//  main.cpp
+//  proxy-audio-device-cli
+//
+//  Created by Max Coplan on 5/19/23.
+//
+
+#include <CoreAudio/CoreAudio.h>
+#include <iostream>
+#include <map>
+#include <vector>
+
+#include "AudioDevice.h"
+#include "ProxyAudioDevice.h"
+
+static void list_audio_devices() {
+  std::vector<AudioObjectID> currentDeviceList =
+      AudioDevice::devicesWithOutputCapabilitiesThatAreNotProxyAudioDevice();
+  for (AudioObjectID &deviceId : currentDeviceList) {
+    CFStringRef name_ref = AudioDevice::copyObjectName(deviceId);
+    char const *name = CFStringGetCStringPtr(
+        name_ref, CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+    if (name == nullptr) {
+      CFIndex size = (sizeof(char) * CFStringGetLength(name_ref)) + 1;
+      char *buf = (char *)malloc(size);
+      bool success = CFStringGetCString(
+          name_ref, buf, size, CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+      assert(success);
+      name = buf;
+    }
+    std::printf("%s\n", name);
+  }
+}
+/**
+ TODO: don't get all the audio devices, just search for the name you're looking
+ for
+ */
+static std::map</** name*/ std::string, /**uid*/ std::string>
+get_audio_devices() {
+  std::map<std::string, std::string> audio_devices;
+  std::vector<AudioObjectID> currentDeviceList =
+      AudioDevice::devicesWithOutputCapabilitiesThatAreNotProxyAudioDevice();
+  for (AudioObjectID &deviceId : currentDeviceList) {
+    std::string name;
+    {
+      CFStringRef name_ref = AudioDevice::copyObjectName(deviceId);
+      char const *name_cstr = CFStringGetCStringPtr(
+          name_ref, CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+      if (name_cstr == nullptr) {
+        CFIndex size = (sizeof(char) * CFStringGetLength(name_ref)) + 1;
+        char *buf = (char *)malloc(size);
+        bool success =
+            CFStringGetCString(name_ref, buf, size,
+                               CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+        assert(success);
+        name_cstr = buf;
+      }
+      name = name_cstr;
+    }
+    std::string uid;
+    {
+      CFStringRef device_uid_ref = AudioDevice::copyDeviceUID(deviceId);
+      char const *device_uid = CFStringGetCStringPtr(
+          device_uid_ref, CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+      if (!device_uid) {
+        CFIndex size = (sizeof(char) * CFStringGetLength(device_uid_ref)) + 1;
+        char *buf = (char *)malloc(size);
+        bool success =
+            CFStringGetCString(device_uid_ref, buf, size,
+                               CFStringBuiltInEncodings::kCFStringEncodingUTF8);
+        assert(success);
+        device_uid = buf;
+      }
+      uid = device_uid;
+    }
+    audio_devices.insert({name, uid});
+  }
+  return audio_devices;
+}
+
+static std::string find_audio_device_uid_from_name(std::string device_name) {
+
+  std::map<std::string, std::string> audio_devices = get_audio_devices();
+  std::map<std::string, std::string>::iterator device_found =
+      audio_devices.find(device_name);
+  assert(device_found != audio_devices.end());
+  std::string device_uid = device_found->second;
+  return device_uid;
+}
+
+static AudioDeviceID audioDeviceIDForBoxUID(std::string device_uid) {
+  return AudioDevice::audioDeviceIDForBoxUID(CFStringCreateWithCString(
+      nullptr, device_uid.c_str(),
+      CFStringBuiltInEncodings::kCFStringEncodingUTF8));
+}
+
+static void set_audio_device_as_active(std::string device_uid) {
+  AudioDeviceID proxy_audio_box = audioDeviceIDForBoxUID(kBox_UID);
+  std::string formatted_device_uid = ({
+    static constexpr char output_literal[] = "outputDevice=";
+    std::size_t output_literal_len = sizeof(output_literal) - 1;
+    std::size_t sizeof_the_thing =
+        sizeof(char) * (output_literal_len + device_uid.size()) + 1;
+    char *buf = (char *)malloc(sizeof_the_thing);
+    for (std::size_t i = 0; i < output_literal_len; ++i) {
+      buf[i] = output_literal[i];
+    }
+    for (std::size_t i = 0; i < device_uid.size(); ++i) {
+      buf[i + output_literal_len] = device_uid[i];
+    }
+    buf;
+  });
+  printf("%s\n", formatted_device_uid.c_str());
+
+  AudioDevice::setObjectName(
+      proxy_audio_box, CFStringCreateWithCString(
+                           nullptr, formatted_device_uid.c_str(),
+                           CFStringBuiltInEncodings::kCFStringEncodingUTF8));
+}
+
+static void select_audio_device(std::string device_name) {
+  std::string device_uid = find_audio_device_uid_from_name(device_name);
+  set_audio_device_as_active(device_uid);
+  return;
+}
+
+int main(int argc, const char *argv[]) {
+  list_audio_devices();
+  select_audio_device("MacBook Pro Speakers");
+
+  return 0;
+}

proxy-audio-device-cli/proxy-audio-device-cli.entitlements

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.device.audio-input</key>
+	<true/>
+</dict>
+</plist>