#!/bin/bash

# Ear tuner for guitar and bass. Install tunebass on your $PATH, and
# symlink it to tunegtr.

# this used to be a one-liner:
#play -n synth 2 pluck ${1:-A2} repeat 99999

case "$0" in
  *gtr*|*guit*)
    notes="E4 B3 G3 D3 A2 E2"
    note=6
    lastnote=6
    ;;
  *)
    notes="G2 D2 A1 E1"
    note=4
    lastnote=4
    ;;
esac

prompt="Space: next string, BkSpc: prev string, 1-$lastnote: strings, q: quit, ?: help"

# these seem like they ought to be the arrow keys, but they're actually
# \n and \b... kcud1 and kcub1 are the 'application mode' versions, which
# doesn't do us any good here.
#down="$( tput cud1 )"
#left="$( tput cub1 )"

# these are correct for xterm and derivatives, and for the linux console.
down="$( printf "\x1b\x5bB" )"
left="$( printf "\x1b\x5bD" )"

up="$( tput cuu1 )"
right="$( tput cuf1 )"
pageup="$( tput kpp )"
pagedown="$( tput knp )"

esc="$( printf "\x1b" )"
enter='
'

oldnote=
pid=
echo "$prompt"
while true; do
  narg="$( echo $notes | cut -d' ' -f $note )"
  if [ "$oldnote" != "$note" ]; then
    [ "$pid" != "" ] && kill "$pid"
    echo -e -n "\rString: $note   Note: $narg"
    tput el
    play --buffer 1024 -qn synth 2 pluck $narg repeat - &>/dev/null &
    pid="$!"
    oldnote="$note"
  fi
  key=
  read -rs -N5 -t 0.1 key
  if [ "$key" != "" ]; then
    case "$key" in
      [1-9])
        [ "$key" -le "$lastnote" ] && note=$key ;;
      a|A|h|H|||$left|$pageup)
        note=$(( note + 1 )); [ $note -gt $lastnote ] && note=1 ;;
      d|D|l|L|' '|'	'|$right|$enter|$pagedown)
        note=$(( note - 1 )); [ $note = 0 ] && note=$lastnote ;;
      s|S|j|J|$down)
        note=$lastnote ;;
      w|W|k|K|$up)
        note=1 ;;
      \?)
       echo
       cat <<EOF
Use space + backspace, arrow keys, pageup/down, WASD, HJKL, or numbers
1 to $lastnote to pick a string. Tune your strings to the notes you hear.
Press Q or Escape to exit.
EOF
        ;;
      $esc|q|Q) break ;;
    esac
  fi
done
kill "$pid"
echo