import AudioToolbox
import CoreAudio
import Foundation

/// Resolves hardware audio input devices, e.g. the built-in or currently
/// selected microphone. Unlike system audio capture, this talks to a real
/// input device directly and needs no process tap or aggregate device.
public class InputDeviceResolver {
  /// Returns the system's current default audio input device.
  public static func defaultInputDevice() throws -> AudioObjectID {
    var address = getPropertyAddress(selector: kAudioHardwarePropertyDefaultInputDevice)
    var deviceID = AudioObjectID(kAudioObjectUnknown)
    var size = UInt32(MemoryLayout<AudioObjectID>.size)

    let status = AudioObjectGetPropertyData(
      AudioObjectID(kAudioObjectSystemObject), &address, 0, nil, &size, &deviceID)

    guard status == kAudioHardwareNoError, deviceID != kAudioObjectUnknown else {
      AudioTeeLogging.logger.error(
        "Failed to resolve default input device", context: ["status": String(status)])
      throw AudioTeeError.defaultInputDeviceUnavailable(status)
    }

    AudioTeeLogging.logger.debug(
      "Resolved default input device", context: ["device_id": String(deviceID)])

    return deviceID
  }
}