#!/usr/bin/env bash
# rice-media - now-playing state for the eww panel and bar.
#
#   rice-media watch          JSON on every track or play-state change (eww deflisten)
#   rice-media position       JSON {pos, text} for the seek bar (polled while the panel is open)
#   rice-media seek <seconds>
#
# Album art is copied into ~/.cache/rice/art under a hash of its URL, so the
# panel only ever points at a file name it created itself.
set -uo pipefail

art_dir="${XDG_CACHE_HOME:-$HOME/.cache}/rice/art"
mkdir -p "$art_dir"

clock() { local s=$1; printf '%d:%02d' $((s / 60)) $((s % 60)); }

art_path() {
  local url="$1" key file path=""
  [[ -n $url ]] || return 0
  key="$url"
  if [[ $url == file://* ]]; then
    path="${url#file://}"
    path=$(printf '%b' "${path//%/\\x}")
    # Browsers reuse one temp file for every track, so local art is keyed by mtime too.
    key+=":$(stat -c %Y -- "$path" 2>/dev/null)"
  fi
  file="$art_dir/$(printf '%s' "$key" | sha1sum | cut -c1-16)"
  if [[ ! -s $file ]]; then
    if [[ -n $path ]]; then
      cp -- "$path" "$file" 2>/dev/null
    elif [[ $url == http*://* ]]; then
      curl -fsSL --max-time 5 -o "$file" -- "$url" 2>/dev/null
    fi
  fi
  [[ -s $file ]] && printf '%s' "$file"
}

emit() {
  local status="$1" player="$2" title="$3" artist="$4" album="$5" url="$6" length="$7"
  local secs=$(( ${length:-0} / 1000000 ))
  jq -cn --arg status "$status" --arg player "$player" --arg title "$title" \
    --arg artist "$artist" --arg album "$album" --arg art "$(art_path "$url")" \
    --argjson length "$secs" --arg lengthText "$( (( secs > 0 )) && clock "$secs")" \
    '{status: $status, player: $player, title: $title, artist: $artist, album: $album,
      art: $art, length: $length, lengthText: $lengthText}'
}

watch() {
  # Unit separator, not tab: read collapses runs of whitespace separators, so an
  # empty field (browsers often send no album) would shift every later field.
  local sep=$'\x1f'
  while :; do
    emit "Stopped" "" "" "" "" "" 0
    playerctl --follow metadata --format \
      "{{status}}${sep}{{playerName}}${sep}{{title}}${sep}{{artist}}${sep}{{album}}${sep}{{mpris:artUrl}}${sep}{{mpris:length}}" 2>/dev/null |
      while IFS="$sep" read -r status player title artist album url length; do
        emit "${status:-Stopped}" "$player" "$title" "$artist" "$album" "$url" "${length:-0}"
      done
    sleep 2
  done
}

case "${1:-}" in
  watch) watch ;;
  position)
    pos=$(playerctl position 2>/dev/null | cut -d. -f1)
    pos=${pos:-0}
    jq -cn --argjson pos "$pos" --arg text "$(clock "$pos")" '{pos: $pos, text: $text}'
    ;;
  seek)
    [[ ${2:-} =~ ^[0-9]+$ ]] || { echo "rice-media: seek takes seconds" >&2; exit 2; }
    playerctl position "$2"
    ;;
  *) sed -n '2,10p' "$0" | sed 's/^# \{0,1\}//'; exit 2 ;;
esac