#!/bin/bash

HOST="$(uname -n)"
ARG0="$(basename "$0")"
TMPD="${TMPDIR:-/tmp}"

PIPEDIR="$TMPD/$ARG0-$USER"
CMDPIPE="$PIPEDIR/cmd-$HOST"
OUTPIPE="$PIPEDIR/out-$HOST"
AUXPIPE="$PIPEDIR/aux-$HOST"

FILE="get_property path\nget_file_name\n"
TIME="get_percent_pos\nget_time_pos\nget_time_length\n"
AUDI="get_audio_bitrate\nget_audio_codec\nget_audio_samples\n"
META="get_property metadata\n"

TAGS=\
"album\narchival location\nartist\nauthor\ncomment\ncomments\n"\
"commissioned\ncopyright\ncreation date\ncropped\ndate\n"\
"digitization time\ndimensions\ndots per inch\nencoder\n"\
"encoder url\nengineer\ngenre\nkeywords\nlightness\nmedium\n"\
"name\npalette setting\nproduct\nsharpness\nsoftware\nsource\n"\
"source form\nsubject\ntechnician\ntime code\ntitle\ntrack\nyear\n"

errmsg ()
{   echo "$@" >&2 ; exit 1 ; }

cmd_echo ()
{   echo "$@" | dd of="$CMDPIPE" oflag=nonblock status=noxfer &>/dev/null ; }

cmd_push ()
{   cmd_echo "$@" || errmsg "not listening" ; }

get_direct ()
{
    cmd_push -ne "$REQT"
    while [ -n "$1" ] ; do
        read -t 3 || errmsg "not responding"
        [[ "$REPLY" == ANS_* ]] || continue
        shift ; $PASS "$REPLY" && continue
        IFS='=' read tag val <<< "$REPLY"
        val="${val#\'}" ; val="${val%\'}"
        IFS='' read $tag <<< "$val"
    done
}

short_info ()
{
    PASS="false"
    REQT="${FILE}${TIME}"
    get_direct {a..e} <>"$OUTPIPE"
}

long_info ()
{
    PASS="false"
    REQT="${FILE}${TIME}${AUDI}${META}"
    get_direct {a..i} <>"$OUTPIPE"
}

pause ()
{
    PASS="echo"
    REQT="${FILE}${TIME}${AUDI}${META}pause\n"
    get_direct {a..i} <>"$OUTPIPE" >"$INPAUSE"
#    fuser -s -k -STOP "$CMDPIPE"
}

resume ()
{
#    [ -f "$INPAUSE" ] &&
#        fuser -s -k -CONT "$CMDPIPE"
    rm -f "$INPAUSE" ; cmd_push "$@"
    tty -s || exit 0 ; short_info
    echo "$ANS_FILENAME: $(position)"
}

on_hold ()
{   [ -f "$INPAUSE" ] && CMDPIPE=/dev/null && OUTPIPE="$INPAUSE" ; }

from_sec ()
{
    IFS='.' read s ss <<< "$1"
    [ $s -lt 3600 ] && printf '%d:%02d\n' $(($s/60)) $(($s%60)) || \
    printf '%d:%02d:%02d\n' $(($s/3600)) $((($s/60)%60)) $(($s%60))
}

position ()
{
    unset HOLD
    [ -f "$INPAUSE" ] && HOLD="[PAUSE]"
    echo "$(from_sec $ANS_TIME_POSITION)" \
         "($(from_sec $ANS_LENGTH)) $ANS_PERCENT_POSITION%" $HOLD
}

for NEWPIPE in "$CMDPIPE" "$CMDPIPE".{a..z} ; do
    [ -p $NEWPIPE ] || break
    CMDPIPE="$NEWPIPE" cmd_echo -n || break
    CMDPIPE="$NEWPIPE"
done
INPAUSE="$CMDPIPE.pause"

unset APPEND DETACH

[ -d "$PIPEDIR" ] && cmd=${1:-i} || cmd=${1:-h}
case "$cmd" in
h|-h|--help)
    echo "Usage: $ARG0 [command|playlist|path...]"
    echo "  <playlist|path...>   -- play in background"
    echo "  d|-d|--direct ...    -- play in foreground"
    echo
    echo "Background mode:"
    echo "  a|-a|--append ...    -- append to current playlist"
    echo "  r|-r|--replace ...   -- replace current playlist"
    echo "  p|-p|--play|--pause  -- toggle play/pause"
    echo "  f|-f|--forward [N]   -- skip N tracks forward"
    echo "  b|-b|--back [N]      -- skip N tracks backward"
    echo "  u|-u|--up-step       -- skip current playlist level"
    echo "  s|-s|--seek <pos>    -- seek to <pos> (% or seconds)"
    echo "  i|-i|--info          -- short 'now playing' info"
    echo "  I|-I|--INFO          -- info + full pathname"
    echo "  l|-l|--long          -- info + metadata"
    echo "  q|-q|--quit          -- stop and exit" ;;

l|-l|--long)
    on_hold ; long_info
    echo "Playing :  $ANS_FILENAME"
    echo " Stream :  $ANS_AUDIO_CODEC, $ANS_AUDIO_BITRATE, $ANS_AUDIO_SAMPLES"
    echo " Played :  $(position)"

    unset delim
    while [ -n "$ANS_metadata" ] ; do
        IFS=',' read head ANS_metadata <<< "$ANS_metadata"
        if echo -ne "$TAGS" | grep -ixq "$head" ; then
            IFS=' ' read ANS_metadata <<< "$ANS_metadata"
            if [[ "$ANS_metadata" == ,* ]] ; then
                unset delim
            else
                printf "\n%7s" "$head" ; delim=' :  '
            fi
        elif [ -n "$delim" ] ; then
            echo -n "$delim$head" ; delim=','
        fi
    done ; echo ;;

i|-i|--info)
    on_hold ; short_info
    echo "$ANS_FILENAME: $(position)" ;;

I|-I|--INFO)
    on_hold ; short_info
    echo "$ANS_path: $(position)" ;;

p|-p|--play|--pause)
    [ -f "$INPAUSE" ] && resume 'pause' || pause ;;

f|-f|--forward)
    resume "pt_step ${2:-1} 1"  ;;

b|-b|--back)
    resume "pt_step -${2:-1} 1" ;;

u|-u|--up-step)
    resume "pt_up_step 1 1" ;;

s|-s|--seek)
    case "$2" in
      +*|-*)  typ='0' ;;
      *%)     typ='1' ;;
      *)      typ='2' ;;
    esac
    resume "seek ${2:-0} $typ" ;;

q|-q|--quit)
    resume 'quit' </dev/null ;;

r|-r|--replace) APPEND=0 ; shift ;;
a|-a|--append)  APPEND=1 ; shift ;;
d|-d|--direct)  DETACH=0 ; shift ;;
*)              DETACH=1 ;;
esac

[ -z "$APPEND$DETACH" ] && exit 0
[ -z "$1" ] && errmsg "no files"

if ! [ -d "$PIPEDIR" ] ; then
    echo "Creating working directory $PIPEDIR"
    mkdir -p -m 0700 "$PIPEDIR" || exit 1
fi

[ -p "$NEWPIPE" ] || mkfifo -m 0600 "$NEWPIPE" || exit 1
[ -p "$OUTPIPE" ] || mkfifo -m 0600 "$OUTPIPE" || exit 1
[ -p "$AUXPIPE" ] || mkfifo -m 0600 "$AUXPIPE" || exit 1

case "$1" in
*.m3u|*.pls|*.asx)
    PLAYLIST="$1" ;;

*)  PLAYLIST="$AUXPIPE"
    for arg ; do if [ ! -e "$arg" ]; then
        echo "$arg"
    elif [[ $arg != /* ]]; then
        find -L ~+/"$arg" -type f | sort
    else
        find -L "$arg" -type f | sort
    fi ; done >"$AUXPIPE" & ;;
esac

if [ -n "$APPEND" ] && cmd_echo -n ; then
    protected="$(sed 's/"/\\\\\\"/g' <<< $PLAYLIST)"
    resume "loadlist \"$protected\" $APPEND"
    exit 0
fi

[ ! -f "$INPAUSE" ] && cmd_echo -n && pause

if [[ "$DETACH" == 0 || "$CMDPIPE" == *.z ]] ; then
    exec mplayer -vo null -playlist "$PLAYLIST"
fi

CMDPIPE="$NEWPIPE"
INPAUSE="$CMDPIPE.pause"
rm -f "$INPAUSE"

mplayer -vo null -playlist "$PLAYLIST" \
        -slave -really-quiet -msglevel global=4 \
        -input file="$CMDPIPE" >"$OUTPIPE" &

dd if="$OUTPIPE" of="$CMDPIPE" count=0 &>/dev/null

short_info ; echo "Playing $ANS_path"