shellsonic

#!/bin/sh

#######
# UI #
#######

help() {
	case $1 in
		search*)
			name="search_play"
			args='"search_query"'
			description="this function first searches the $args, then opens the menu(fzf,[d|be]menu,[t|r|w]ofi) with the results,then calls the play function to play the music"
			;;
		loop)
			name="loop"
			args='"print"'
			description="this function runs in a loop to play the next music if the current music is successfully finished
			this function should be put as background process
			passing print argument will show the progress to stdout"
			;;
		play*)
			name="play_next"
			args='"menu"'
			description="immediately plays the next song stored in $tmpdir/next file in mpv if argument is empty
			passing $args argument will show the $args(fzf,[d|be]menu,[t|r|w]ofi) for selecting what should be played"
			;;
		*)
			name="[ <function_name> ]"
			args="[ <function_arg> ]"
			description="
			<function_name>	<function_arg>	<function_description>

			search_play	search_query	searches first then plays the music in mpv
			play_next	menu(optional)	plays the next music in $tmpdir/next file
			loop		print(optional)	plays the next music after the current is finished (run it as background process)

			tip:
			type ${0##*/} help <function_name> to get individual help
			"
			;;
	esac
	while read -r line; do
		printf "%s\n" "$line"
	done <<-EOF

		Usage :
		${0##*/} $name $args

		Description :
		$description
	EOF
	exit 0
}

info() {
	#shellcheck disable=SC2059
	printf "\033[2K\r\033[1;${2:-36}m${1}\033[0m"
}

success() {
	info "$1" "32"
}

ask() {
	info "$1" "33"
}

err() {
	info "$1\n" "31"
}

menu() {
	if command -v bemenu >/dev/null; then
		bemenu -R 20 $3 --accept-single --fn 'IBM Plex Sans 15' -i -c -W 0.5 -B 2 -p "$1" -l 26 -I "${2:-0}" -P ">>" --bdr="#$GLOBAL_ACCENT" --tf="#$GLOBAL_ACCENT" --hf="#$GLOBAL_ACCENT"
	else
		fzf --prompt="$1" --height=25 --reverse --border=horizontal --header="${2:-0}" --marker=">>"
	fi
}

cleanup_shit() {
	pgrep -f "$socket" >/dev/null && pkill -f "$socket"
	rm -rdf "$tmpdir"
	exit 0
}

##########
# CONFIG #
##########

# create/update the variable value
save_config() {
	grep -q "^$1=" "$config_file" && sed -i "s|$1=.*|$1=$2|g" "$config_file" >/dev/null 2>&1 || printf "%s=%s\n" "$1" "$2" >>"$config_file"
	[ -z "$3" ] && success "$1 Saved in config, to override config values pass it as environment variable\n"
}

# checks the variable existance, if it's filled
# if either or both are false, it ask the user to submit them.
ensure_config() {
	grep -qE "$1=(.+)" "$config_file" && return 0
	ask "$2"
	read -r query
	save_config "$1" "$query"
	unset query
}

# checks the config, does the auth and check if config is correct
# if not, then present the user to re-configure it.
setup() {
	info "Checking Config.."
	[ -f "$config_file" ] || : >"$config_file"
	ensure_config "SS_URL" "Where is Subsonic Server hosted? : "
	ensure_config "SS_USER" "Please type the username : "
	ensure_config "SS_PASS" "Please type the password : "

	# shellcheck source=/dev/null
	. "$config_file"

	info "Checking Auth..."
	case "$(subsonic_api "getUser" "username=$SS_USER")" in
		*'"status":"ok"'*)
			info ""
			return 0
			;;
		*'"code":40'* | *'"message":"Wrong username or password"'*)
			err "Wrong username or password."
			save_config "SS_USER" "" "noprint"
			save_config "SS_PASS" "" "noprint"
			unset SS_USER SS_PASS
			exit 1
			;;
		*)
			err "Unable to connect to server."
			exit 1
			;;
	esac
}

###########
# NETWORK #
###########

# generates a random token with salt to maximize security.
prepare_token() {
	SALT="$(tr -dc '[:alnum:]' </dev/urandom | head -c16)"
	TOKEN="$(printf '%s%s' "$SS_PASS" "$SALT" | md5sum | cut -d' ' -f1)"
}

# all the api calls are done by this function
subsonic_api() {
	prepare_token
	curl -s -A "$AGENT" "$SS_URL/rest/${1}?u=$SS_USER&t=$TOKEN&s=$SALT&v=$API_VERSION&c=${0##*/}&f=json&${2}" -G
}

# fetches the track list and present it in usable format for code
get_list() {
	subsonic_api "$1" "$2" | sed 's/movements/\n/g' | sed -nE 's|.*\{"id":"([^"]*)",.*"title":"([^"]*)","album":".*","artist":"([^"]*)".*"coverArt":"([^"]*)",.*|\2 BY \3\t\1\t\4|p' | sed "s/\\\u0026/and/g;s/'/-/g;/^$/d"
}

# get next songs basec on current song, to make a playlist to continue playing.
get_music_list() {
	artist_id=$(subsonic_api "getSong" "id=$1" | sed -nE 's|.*"artistId":"([^"]*)",.*|\1|p')

	similarsongs2=$(get_list "getSimilarSongs2" "id=$artist_id&count=25")
	#shellcheck disable=SC1091,SC2094
	[ -n "$similarsongs2" ] && printf '%s\n' "$similarsongs2" | sed -e "$(cut -f2 "$tmpdir/next" | sed 's|^|/|g;s|$|/d|g')" >>"$tmpdir/next"

	similarsongs=$(get_list "getSimilarSongs" "id=$1&count=25")
	#shellcheck disable=SC1091,SC2094
	[ -n "$similarsongs" ] && printf '%s\n' "$similarsongs" | sed -e "$(cut -f2 "$tmpdir/next" | sed 's|^|/|g;s|$|/d|g')" >>"$tmpdir/next"

	#shellcheck disable=SC1091,SC2094
	[ -z "$similarsongs" ] && [ -z "$similarsongs2" ] && get_list "getRandomSongs" "count=25" | sed -e "$(cut -f2 "$tmpdir/next" | sed 's|^|/|g;s|$|/d|g')" >>"$tmpdir/next"
}

get_lyrics() {
	subsonic_api "getLyricsBySongId" "id=$1" | sed 's|[\{\}]|\n|g' | sed -nE 's|.*"start":([0-9]*),"value":"(.*)"$|\1\t\2|p' | sed 's/\(\(\w\+\W\+\)\{10\}\)/\1\\n/g' >"$tmpdir/lyrics"
}

#############
# FUNCTIONS #
#############

#this function does exactly what it says, it should run in the background
#it plays next song after the current song get played completely
#it does nothing until u run the search_play function for first track and then this code kicks in
loop() {
	trap cleanup_shit INT HUP TERM
	socat -U - "UNIX-CONNECT:$socket" | while read -r event; do
		#look for eof event
		if printf "%s" "$event" | grep -q "end-file.*eof"; then
			i=$(cat "$tmpdir/counter")
			: $((i += 1))
			subsonic_api "scrobble" "submission=true&id=$(sed -nE 's/^ID="([^"]*)"/\1/p' "$tmpdir/current")"
			pgrep -f "$socket" >/dev/null || continue
			next=$(sed -n "${i}p" "$tmpdir/next")
			[ -z "$next" ] && break
			play "$next" "$1"
			printf '%s' "$i" >"$tmpdir/counter"
			[ -f "$tmpdir/playlist-mode" ] && continue
			currentsongID=$(printf '%s' "$next" | cut -f2)
			[ -n "$currentsongID" ] && tail -1 "$tmpdir/next" | grep -q "$currentsongID" && get_music_list "$currentsongID"
		fi
	done
	cleanup_shit
}

#run this if u want to listen to songs and start playlist
#call this by script-name search_play [ search_query ]
search_play() {
	[ -z "$1" ] && query=$(: | menu "SS-music [Search]:") || query="$1"
	[ -z "$query" ] && notify-send -e "Err.. Search query empty" -u critical -h "string:x-canonical-private-synchronous:${0##*/}" && return 1
	case "$query" in
		playlist)
			playlist=$(subsonic_api "getPlaylists" | sed 's/readonly/\n/g' | sed -nE 's|.*"id":"([^"]*)","name":"([^"]*)","songCount":([0-9]*),.*|\2 (\3)\t\1|p' | menu "SS-music [Playlist]:" "" "--ifne")
			[ -z "$playlist" ] && notify-send -e "Err.. No playlist selected" -u critical -h "string:x-canonical-private-synchronous:${0##*/}" && return 1
			playlist_id=$(printf '%s' "$playlist" | cut -f2)
			playlist_name=$(printf '%s' "$playlist" | cut -f1)
			playlist_data=$(get_list "getPlaylist" "id=$playlist_id&size=-1" | shuf | tee "$tmpdir/next")
			[ -z "$playlist_data" ] && notify-send -e "Err.. Playlist $playlist_name empty" -u critical -h "string:x-canonical-private-synchronous:${0##*/}" && return 1
			song=$(printf '%s' "$playlist_data" | head -1)
			[ -z "$song" ] && return 1
			play "$song" "verbose"
			touch "$tmpdir/playlist-mode"
			;;
		*)
			song=$(get_list "search3" "query=$(printf '%s' "$query" | tr ' ' '+')" | menu "SS-music [Play]:" "" "--ifne")
			[ -z "$song" ] && return 1
			printf "%s\n" "$song" >"$tmpdir/next"
			play "$song" "verbose" "1"
			rm -f "$tmpdir/playlist-mode"
			;;
	esac
	printf "1" >"$tmpdir/counter"
	pgrep -f "${0##*/} loop" >/dev/null || setsid -f "$0" loop
}

#this function does all the heavy lifting
#it uses the track id to generate stream url and pass to mpv
#then generates playlist, fetches lyrics, scrobble now-playing the current track
play() {
	title=$(printf '%s' "$1" | cut -f1)
	id=$(printf '%s' "$1" | cut -f2)
	coverId=$(printf '%s' "$1" | cut -f3)
	[ -z "$id" ] && err "[ opensubsonic ] Invalid Id" && exit 1

	prepare_token
	stream_url="$SS_URL/rest/stream?id=$id&u=$SS_USER&t=$TOKEN&s=$SALT&v=$API_VERSION&c=${0##*/}"
	[ -n "$2" ] && success "Playing $title on mpv\n"
	curl -s "$SS_URL/rest/getCoverArt?id=$coverId&u=$SS_USER&t=$TOKEN&s=$SALT&v=$API_VERSION&c=${0##*/}&size=300" -o "$tmpdir/default.jpg" && notify-send -e -h "string:x-canonical-private-synchronous:${0##*/}" -i "$tmpdir/default.jpg" "Now Playing" "$title" -t 5000
	pgrep -f "$socket" >/dev/null || setsid -f mpv --really-quiet --input-ipc-server="$socket" --idle --quiet --no-audio-display >/dev/null
	while [ ! -S "$socket" ]; do sleep 1; done
	printf '{"command":["loadfile","%s","replace"]}\n' "$stream_url" | socat -u - "$socket"
	song_title="${title%% BY *}"
	artist="${title#* BY }"
	printf 'SONG="%s"\nARTIST="%s"\nID="%s"' "$song_title" "$artist" "$id" >"$tmpdir/current"

	# run complementary functions to make listening more fun...
	get_lyrics "$id" &
	[ -n "$3" ] && get_music_list "$id" &
	subsonic_api "scrobble" "id=$id&submission=false" &
}

#call this by script-name "play_next" for playing next song immediately
#or add "menu" after "play_next" to show menu for selecting and playing next song immediately
#like this script-name "play_next" "menu"
play_next() {
	pgrep -f "$socket" || return 0
	i=$(cat "$tmpdir/counter")
	if [ -z "$1" ]; then
		: $((i += 1))
		play "$(sed -n "${i}p" "$tmpdir/next")"
	else
		#shellcheck source=/dev/null
		#shellcheck disable=SC1091
		[ -f "$tmpdir/current" ] && . "$tmpdir/current"
		notify-send -e -h "string:x-canonical-private-synchronous:${0##*/}" -i "$tmpdir/default.jpg" "Listening @ $(basename "$0")" "$SONG BY $ARTIST"
		next=$(nl -n'ln' "$tmpdir/next" | sed "s/^$i /*& /" | menu "SS-music [play-next]: " "$((i - 1))")
		[ -z "$next" ] && return 0
		i=$(printf '%s' "$next" | sed 's/^*//g' | cut -f1 | tr -d ' ')
		play "$(printf '%s' "$next" | cut -f2-)" "verbose"
	fi
	printf '%s' "$i" >"$tmpdir/counter"
	currentsongID=$(sed -nE 's/^ID="([^"]*)"/\1/p' "$tmpdir/current")
	[ -n "$currentsongID" ] && tail -1 "$tmpdir/next" | grep -q "$currentsongID" && get_music_list "$currentsongID"
}

#############
# VARIABLES #
#############

API_VERSION="1.16.1"
AGENT="${0##*/} 1.0.1"
tmpdir="/tmp/${0##*/}"
socket="$tmpdir/${0##*/}-mpvsocket"
config_file="${XDG_STATE_HOME:-$HOME/.local/state}/${0##*/}-config"

########
# MAIN #
########

if [ -z "$1" ] || [ "$1" = "help" ]; then
	help "$2"
fi

setup
mkdir -p "$tmpdir"

case "$1" in
	search_play) search_play "$2" "$3" ;;
	play_next) play_next "$2" ;;
	play) play "$2" ;;
	loop) loop "$2" ;;
	*)
		err "Function does not exist!"
		help
		;;
esac