#!/bin/sh
# mpd-add: fuzzy-pick a track from the MPD library and play it right away.
# Works in a terminal (fzf) or launched from a menu (aurora-run).
#
# Usage: mpd-add [-q]
#   -q   queue the track right after the current one, but don't jump to it

QUEUE_ONLY=0
[ "${1:-}" = "-q" ] && QUEUE_ONLY=1

# Notifications replace each other instead of stacking (dunst/mako/swaync).
notify() { # notify [-u urgency] <title> <body>
    urgency=normal
    if [ "$1" = "-u" ]; then urgency=$2; shift 2; fi
    echo "$1: $2" >&2
    command -v notify-send >/dev/null 2>&1 || return 0
    notify-send -a mpd-add -u "$urgency" \
        -h string:x-canonical-private-synchronous:mpd-add \
        -h string:x-dunst-stack-tag:mpd-add \
        "$1" "$2"
}

if ! mpc status >/dev/null 2>&1; then
    notify -u critical "MPD unreachable" "Is mpd running?"
    exit 1
fi

# One "Artist - Title · Album<TAB>file" line per track (the album makes typing an
# album name list its songs). Untagged tracks fall back to the file name (minus
# extension and a leading track number), and the artist is only prefixed when
# that name doesn't already contain one. Singles (album = title) skip the album.
library=$(mpc listall -f '%artist%\t%title%\t%album%\t%file%' | awk -F'\t' '{
    artist = $1; title = $2; album = $3; file = $4
    if (title == "") {
        title = file
        sub(/.*\//, "", title); sub(/\.[^.]*$/, "", title); sub(/^[0-9]+[.)]? *-? */, "", title)
        if (index(title, " - ")) artist = ""
    }
    line = artist != "" ? artist " - " title : title
    sub(/ - (Single|EP)$/, "", album)
    if (album != "" && album != title) line = line " · " album
    print line "\t" file
}')
if [ -z "$library" ]; then
    notify -u critical "MPD library is empty" "Try: mpc update"
    exit 1
fi

if [ -t 0 ]; then
    filename=$(printf '%s\n' "$library" | fzf -d '\t' --with-nth 1 | cut -f2)
else
    # aurora-run can't hide a column: show the names, map the index back to the file.
    n=$(printf '%s\n' "$library" | cut -f1 | aurora-run -d -l 30 -p 'play: ' --index) || exit 0
    [ "$n" -ge 0 ] 2>/dev/null || exit 0
    filename=$(printf '%s\n' "$library" | sed -n "$((n + 1))p" | cut -f2)
fi

# Cancelled (Esc): nothing to do.
[ -z "$filename" ] && exit 0

# Position of the current song (1-based); empty if nothing is playing/paused.
cur=$(mpc -f '%position%' current)

if ! mpc insert "$filename" >/dev/null; then
    notify -u critical "Couldn't add track" "$filename"
    exit 1
fi

if [ "$QUEUE_ONLY" -eq 1 ]; then
    notify "Queued next" "$filename"
    exit 0
fi

# Jump straight to the song we just inserted. It lands right after the current
# song, or at the end of the queue when nothing is playing. Using an explicit
# position avoids `mpc next`, which misbehaves when stopped or paused.
if [ -n "$cur" ]; then
    target=$((cur + 1))
else
    target=$(mpc playlist | wc -l)
fi

if mpc play $target >/dev/null; then
    now=$(mpc current)
    notify "Now playing" "${now:-$filename}"
else
    notify -u critical "Couldn't start playback" "$filename"
    exit 1
fi