librespot-onevent

#!/bin/bash

## Configurações 
## CACHE_PATH
## BEARER_TOKEN_FILE
## CLIEND_ID
## CLIENT_SECRET
## VOLUME_ICON
source '/home/modolo/.config/librespot/config.env'

## Requisita um novo token
request_access_token() {
  local bearer
  bearer="$(echo -n "$CLIEND_ID:$CLIENT_SECRET" | base64 -w0 )"
  curl --silent -H "Authorization: Basic $bearer" \
    -d "grant_type=client_credentials" \
    -X "POST" 'https://accounts.spotify.com/api/token'
}

## Retorna as informações do track no formato json
request_track_info() {
  local access_token="$1"
  local track_id="$2"
  local market="$3"
  curl --silent -X "GET" "https://api.spotify.com/v1/tracks/$track_id?market=$market" \
         -H "Accept: application/json" \
         -H "Content-Type: application/json" \
         -H "Authorization: Bearer $access_token" 
}

## Persiste o token
save_acess_token() {
  local bearer="$1"
  echo -n "$bearer" >"$CACHE_PATH/$BEARER_TOKEN_FILE"
}

## Recupera um token salvo
retrieve_access_token() {
  cat "$CACHE_PATH/$BEARER_TOKEN_FILE"
}

## Testa de é um track válido
# TODO - Melhorar o teste de erros
is_access_token_expired() {
  local track_info="$1"
  local expired
  expired=$(echo "$track_info" | jq -r '.error')
  if [ "$expired" == "null" ]
  then
    echo "VALID"
  else
    echo "$track_info" | systemd-cat -t librespot -p info
    echo "INVALID"
  fi
}

## Obtem um novo token
refresh_token() {
  local token_info
  token_info=$(request_access_token)
  local access_token
  access_token=$(echo "$token_info" | jq -r '.access_token')
  save_acess_token "$access_token"
  echo "$access_token"
}

## Transforma mileseconds em horas, minutos e segundos
format_time() {
  local mileseconds=$1
  local seconds
  seconds=$(( "$mileseconds"/1000 ))
  if [ "$seconds" -ge "3600" ]
  then
    date -d@${seconds} -u +%H:%M:%S
  else
    date -d@${seconds} -u +%M:%S
  fi
}

## Notifica alterações de volume
notify_volume()  {
  local new_volume=$1
  # Gnome e Ubuntu ignoram esse valor
  local expire_time=${2:-5000}
  local volume
  volume=$(echo "scale=4;($new_volume/65535)*100" | bc)
  volume=$(printf "%02.2f" "$(echo "$volume" | tr '.' ',')")
  local hints
  # urgency 'low' é 0
  hints="{\"urgency\": <byte 0>, \"transient\": <int32 1>}"
  local id
  id=$(cat "$XDG_RUNTIME_DIR/librespot.volume.id" 2>/dev/null)
  local re='^[0-9]+$'
  if [[ ! ${id} =~ $re ]] ; then
    id=1
  fi
  echo "volume_id: ${id}" | systemd-cat -t librespot -p info
  echo "volume: ${volume}" | systemd-cat -t librespot -p info
  id=$(gdbus call --session --dest org.freedesktop.Notifications \
    --object-path /org/freedesktop/Notifications \
	  --method org.freedesktop.Notifications.Notify \
	  "LIBRESPOT_VOLUME" "$id" \
	  "${VOLUME_ICON}" "Spotify" "Volume [ $volume% ]" [] "$hints" "$expire_time" \
    | sed -e 's/(uint32 //' -e 's/,)//')
  echo "$id" >"$XDG_RUNTIME_DIR/librespot.volume.id"
}

## Notifica as informações da trilha
notify_track() {
  local track_info="$1"
  # Gnome e Ubuntu ignoram esse valor
  local expire_time=${2:-2500}
  # shellcheck disable=SC2155
  declare -A track=$(echo "$track_info" | jq '.album.name,.album.images[2].url,.name,.duration_ms' \
    | tr '\n' '\t' \
    | awk -F'\t' '{printf "( [album_name]=%s [album_image_url]=%s [name]=%s [duration_ms]=%s )",$1,$2,$3,$4}')
  local album_name=${track[album_name]}
  local album_image_url=${track[album_image_url]}
  local track_name=${track[name]}
  local track_duration
  track_duration=$(format_time "${track[duration_ms]}")

  # Remove a anterior caso exista
  rm -f "${XDG_RUNTIME_DIR}"/librespot.album_image.* 2>/dev/null
  local album_image
  album_image=$(mktemp "$XDG_RUNTIME_DIR/librespot.album_image.XXXXXXXXXX")

  wget -q "${album_image_url}" -O "${album_image}"

  echo "Album: ${album_name}" | systemd-cat -t librespot -p info
  echo "Image URL: ${album_image_url}" | systemd-cat -t librespot -p info
  echo "Image info: $(file -b "${album_image}")" | systemd-cat -t librespot -p info
  echo "Track: ${track_name}" | systemd-cat -t librespot -p info
  echo "Duration: ${track_duration}" | systemd-cat -t librespot -p info

  local hints
  # urgency 'low' é 0
  hints="{\"urgency\": <byte 0>, \"transient\": <int32 1>}"
  local id
  id=$(cat "$XDG_RUNTIME_DIR/librespot.track.id" 2>/dev/null)
  local re='^[0-9]+$'
  if [[ ! ${id} =~ $re ]] ; then
    id=1
  fi
  id=$(gdbus call --session --dest org.freedesktop.Notifications \
    --object-path /org/freedesktop/Notifications \
	  --method org.freedesktop.Notifications.Notify \
	  "LIBRESPOT_TRACK" "$id" \
	  "${album_image}" "${album_name}" "<b>${track_name}</b> ${track_duration}" [] "$hints" "$expire_time" \
    | sed -e 's/(uint32 //' -e 's/,)//')
  echo "$id" >"$XDG_RUNTIME_DIR/librespot.track.id"
}

## Trilha tocando
playing_track() {
  local track_id="$1"
  local market="BR"
  local track_info=""
  if [ -f "$CACHE_PATH/$BEARER_TOKEN_FILE" ]
  then
    local access_token
    local track_info
    local expired
    access_token=$(retrieve_access_token)
    track_info=$(request_track_info "$access_token" "$track_id" "$market")
    # TODO - Testar os possíveis erros retornados
    expired=$(is_access_token_expired "$track_info")
    if [ "$expired" == "INVALID" ]
    then
      echo "Renovando o token" | systemd-cat -t librespot -p info
      access_token=$(refresh_token)
      track_info=$(request_track_info "$access_token" "$track_id" "$market")
    fi
  else
    echo "Criando o arquivo de token em $CACHE_PATH/$BEARER_TOKEN_FILE" | systemd-cat -t librespot -p info
    access_token=$(refresh_token)
    track_info=$(request_track_info "$access_token" "$track_id" "$market")
  fi
  echo "$track_info"
}

## Testa os vários eventos
case "$PLAYER_EVENT" in
  "playing")
    # shellcheck disable=SC2153
    track_info=$(playing_track "$TRACK_ID")
    notify_track "$track_info" 5000
    exit 0
    ;;
  "volume_set")
    if [[ -f "${CACHE_PATH}/started" || -f "${CACHE_PATH}/reloaded" ]]
    then
      rm -f "${CACHE_PATH}/started" &>/dev/null
      rm -f "${CACHE_PATH}/reloaded" &>/dev/null
      exit 0
    fi
    re='^[0-9]+$'
    # shellcheck disable=SC2153
    if [[ ${VOLUME} =~ $re ]] ; then
      # shellcheck disable=SC2153
      notify_volume "$VOLUME" 3000
    fi
    exit 0
    ;;
esac