audio-device

#!/usr/bin/env bash

set -euo pipefail

assert_command() {
  if ! type "${1}" >/dev/null 2>&1; then
    echo "${2:-"command not found: ${1}"}"
    exit 1
  fi
}

assert_val() {
  if [[ -z "${1}" ]]; then
    echo "${2}"
    exit 1
  fi
}

assert_func() {
  if ! declare -F "${1}" >/dev/null; then
    echo "${2}"
    exit 1
  fi
}

__linux_device_type() {
  local device_type="${1}"
  case "${1}" in
    i*|so*) echo "source";;
    o*|si*) echo "sink";;
    *)
      echo "invalid device type: ${1}"
      exit 1
  esac
}

__linux_describe_device() {
  local -r device_type="$(__linux_device_type "${1}")"
  local -r index=$(( ${2} ))
  local -r key="${3}"

  local delim=":"
  if [[ "${key}" = *"."* ]]; then
    delim='"'
  fi

  pacmd list-"${device_type}s" \
    | sed -n "/index: ${index}/,/index: /{/index: /!p;}" \
    | grep -e "${key}" | cut -d "${delim}" -f2 | head -1 \
    | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' \
  || echo ""
}

__linux_device_name() {
  local -r device_type="$(__linux_device_type "${1}")"
  local -r index="${2}"

  local device_name
  for key in "device.product.name" "bluez.alias" "device.description"; do
    device_name="$(__linux_describe_device "${device_type}" "${index}" "${key}")"
    if test -n "${device_name}"; then
      echo "${device_name}"
      return
    fi
  done
}

__linux_current_device_index() {
  local -r device_type="$(__linux_device_type "${1}")"
  pacmd list-"${device_type}s" | grep "\* index: " | sed -e 's/ *\* *index: *//'
}


__linux_list_devices() {
  local -r device_type="$(__linux_device_type "${1}")"

  local -a devices
  mapfile -t devices < <(pactl list short "${device_type}s")

  local index
  for device in "${devices[@]}"; do
    index="$(echo "${device}" | awk '{print $1}')"
    if [[ "$(__linux_describe_device "${device_type}" "${index}" "flags")" = *HARDWARE* ]]; then
      echo "${index} $(__linux_device_name "${device_type}" "${index}")"
    fi
  done
}

_linux_current() {
  local -r input_device="$(__linux_device_name input "$(__linux_current_device_index input)")"
  local -r output_device="$(__linux_device_name output "$(__linux_current_device_index output)")"

  local -n variable="${1:-}_device"
  
  if test -z "${variable:-}"; then
    echo " Input: ${input_device}"
    echo "Output: ${output_device}"
  else
    echo "${variable}"
  fi
}

_linux_input() {
  local -r device_type="$(__linux_device_type input)"

  local selected_index
  selected_index="$(__linux_list_devices "${device_type}" | fzf | cut -d' ' -f1)"

  pactl set-default-source "${selected_index}"
}

_linux_output() {
  local -r device_type="$(__linux_device_type output)"

  local selected_index
  selected_index="$(__linux_list_devices "${device_type}" | fzf | cut -d' ' -f1)"

  pactl set-default-sink "${selected_index}"

  if [[ "$(__linux_describe_device "${device_type}" "${selected_index}" "device.bus")" = "bluetooth" ]]; then
    local -A profile_map=(["Headset Head Unit (w/ Microphone)"]=headset_head_unit ["High Fidelity Playback (w/o Micrphone)"]=a2dp_sink)
    local -r profile="${profile_map[$(printf "%s\n" "${!profile_map[@]}" | fzf --header='Bluetooth Sound Profile')]}"
    pacmd set-card-profile "$(__linux_describe_device "${device_type}" "${selected_index}" "card" | awk '{ print $1 }')" "${profile}"
  fi
}

_darwin_current() {
  local -r input_device="$(SwitchAudioSource -t input -c)"
  local -r output_device="$(SwitchAudioSource -t output -c)"

  local -n variable="${1:-}_device"

  if test -z "${variable:-}"; then
    echo " Input: ${input_device}"
    echo "Output: ${output_device}"
  else
    echo "${variable}"
  fi
}

_darwin_input() {
  local -r device="$(SwitchAudioSource -t input -a | fzf --header='Input Device')"
  SwitchAudioSource -t input -s "${device}"
}

_darwin_output() {
  local -r device="$(SwitchAudioSource -t output -a | fzf --header='Output Device')"
  SwitchAudioSource -t output -s "${device}"
}

assert_command fzf

declare OS=""
case "${OSTYPE}" in
  darwin*)
    assert_command SwitchAudioSource
    OS="darwin"
    ;;
  linux*)
    assert_command pacmd
    assert_command pactl
    OS="linux"
    ;;
  *)
    echo "Unsupported OS!"
    exit 1;;
esac

declare -r cmd="${1:-"help"}"
shift || true

case "${cmd}" in
  source)
    cmd="input";;
  sink)
    cmd="output";;
  help)
    cat << HELP
USAGE:
  audio-device current [input|output]
  audio-device input
  audio-device output
HELP
    exit 0
esac

declare -r func="_${OS}_${cmd}"
assert_func "${func}" "invalid command: ${cmd}"

$func $@