#!/usr/bin/env bash
# rice-bt - bluetooth state for the eww panel, and the actions it runs.
#
#   rice-bt list               JSON: power, discovery, paired and nearby devices
#   rice-bt power on|off|toggle
#   rice-bt scan               look for new devices for 15 seconds
#   rice-bt toggle <MAC>       connect or disconnect; new devices are paired and trusted first
#   rice-bt forget <MAC>
#
# Device names are chosen by the device, so the panel only ever passes MAC
# addresses, and every MAC is checked before it is used.
set -uo pipefail

run="${XDG_RUNTIME_DIR:-/tmp}/rice"
mkdir -p "$run"

say()  { rice-notify send "$1" "${2:-}" -i bluetooth; }
poke() { date +%s%N > "$run/bt.rev"; }
mac_ok() { [[ ${1:-} =~ ^([0-9A-F]{2}:){5}[0-9A-F]{2}$ ]] || { echo "rice-bt: not a MAC address: '${1:-}'" >&2; exit 2; }; }
powered() { bluetoothctl show 2>/dev/null | grep -q 'Powered: yes'; }

glyph() {
  case "$1" in
    audio-headset|audio-headphones) echo 󰋋 ;;
    audio-card)                     echo 󰓃 ;;
    input-keyboard)                 echo 󰌌 ;;
    input-mouse)                    echo 󰍽 ;;
    input-gaming)                   echo 󰊴 ;;
    phone)                          echo 󰏲 ;;
    computer)                       echo 󰍹 ;;
    *)                              echo 󰂯 ;;
  esac
}

device_json() {
  local mac="$1" info name icon paired connected battery
  info=$(bluetoothctl info "$mac" 2>/dev/null)
  name=$(sed -n 's/^\s*Alias: //p' <<<"$info" | head -n1)
  icon=$(sed -n 's/^\s*Icon: //p' <<<"$info" | head -n1)
  paired=$(grep -q 'Paired: yes' <<<"$info" && echo true || echo false)
  connected=$(grep -q 'Connected: yes' <<<"$info" && echo true || echo false)
  battery=$(sed -n 's/^\s*Battery Percentage: .*(\([0-9]*\))/\1/p' <<<"$info" | head -n1)
  jq -cn --arg mac "$mac" --arg name "${name:-$mac}" --arg glyph "$(glyph "$icon")" \
    --argjson paired "$paired" --argjson connected "$connected" --arg battery "$battery" \
    '{mac: $mac, name: $name, glyph: $glyph, paired: $paired, connected: $connected,
      battery: (if $battery == "" then "" else $battery + "%" end),
      sub: (if $connected then "connected" elif $paired then "paired" else "tap to pair" end)}'
}

list() {
  local on=false discovering=false paired="[]" nearby="[]" mac
  if powered; then
    on=true
    bluetoothctl show 2>/dev/null | grep -q 'Discovering: yes' && discovering=true
    paired=$(bluetoothctl devices Paired 2>/dev/null | awk '{ print $2 }' | grep -E '^([0-9A-F]{2}:){5}[0-9A-F]{2}$' |
      while read -r mac; do device_json "$mac"; done | jq -cs 'sort_by(.connected | not)')
    nearby=$(comm -23 <(bluetoothctl devices 2>/dev/null | awk '{ print $2 }' | sort) \
                      <(bluetoothctl devices Paired 2>/dev/null | awk '{ print $2 }' | sort) |
      grep -E '^([0-9A-F]{2}:){5}[0-9A-F]{2}$' | head -n 8 |
      while read -r mac; do device_json "$mac"; done | jq -cs '[.[] | select(.name != .mac)]')
  fi
  jq -cn --argjson powered "$on" --argjson discovering "$discovering" \
    --argjson paired "$paired" --argjson nearby "$nearby" \
    '{powered: $powered, discovering: $discovering, paired: $paired, nearby: $nearby,
      connected: ([$paired[] | select(.connected)] | length)}'
}

case "${1:-}" in
  list) list ;;
  power)
    case "${2:-toggle}" in
      on)  rfkill unblock bluetooth 2>/dev/null; bluetoothctl power on >/dev/null ;;
      off) bluetoothctl power off >/dev/null ;;
      *)   if powered; then bluetoothctl power off >/dev/null; else rfkill unblock bluetooth 2>/dev/null; bluetoothctl power on >/dev/null; fi ;;
    esac
    poke ;;
  scan)
    powered || bluetoothctl power on >/dev/null
    setsid -f bluetoothctl --timeout 15 scan on >/dev/null 2>&1
    poke ;;
  toggle)
    mac_ok "${2:-}"; mac="$2"
    info=$(bluetoothctl info "$mac" 2>/dev/null)
    name=$(sed -n 's/^\s*Alias: //p' <<<"$info" | head -n1)
    if grep -q 'Connected: yes' <<<"$info"; then
      bluetoothctl disconnect "$mac" >/dev/null && say "Disconnected" "$name"
    else
      if ! grep -q 'Paired: yes' <<<"$info"; then
        bluetoothctl --timeout 20 pair "$mac" >/dev/null 2>&1 || { say "Pairing failed" "$name"; exit 1; }
        bluetoothctl trust "$mac" >/dev/null
      fi
      bluetoothctl --timeout 15 connect "$mac" >/dev/null 2>&1 && say "Connected" "$name" || say "Could not connect" "$name"
    fi
    poke ;;
  forget)
    mac_ok "${2:-}"
    bluetoothctl remove "$2" >/dev/null && say "Forgot device" "$2"
    poke ;;
  *) sed -n '2,10p' "$0" | sed 's/^# \{0,1\}//'; exit 2 ;;
esac