#!/bin/sh
# RADISH
# a new and improved RADIO that can play local files and noise.
# XXX: WIP

usage() {
	cat <<EOF
RADISH: radio, music, static
USAGE:	radish [-h|-k|-r|-s|-S]
	radish -l [NAME]
	radish [STATION]

FLAGS:
 -h		Show this help and exit.
 -s		Show radish's status and exit.
 -S		Show radish's status indefinitely.
 -k		Kill the currently-playing radish invocation.
 -r		Replay most recently-played station.

OPTIONS:
 -l [NAME]	List available stations.
		If NAME is given, narrow the list to those matching it.

PARAMETERS:
 STATION	Which configured station to play.
		Stations are defined in the \$RADISH_STATION_FILE
		(default: $RADISH_STATION_FILE).
		If STATION is not present, or if it matches
		more than one station, radish will present a menu.
EOF
	exit ${1:-0}
}

config() {
	: "${RADISH_STATION_FILE:=${XDG_CONFIG_HOME:-$HOME/.config}/radish/stations}"
	RADISH_PID_FILE=/tmp/radish.pid
	RADISH_STATUS_FILE=/tmp/radish.status
	RADISH_LP_FILE="${XDG_CACHE_HOME:-$HOME/.cache}/radish.lp"
}

main() {
	config
	while getopts :hkrsSl: opt; do
		case "$opt" in
		h) usage ;;
		k) radish_kill ;;
		r) set -- "$(cat "$RADISH_LP_FILE")" ;;
		s) radish_status ;;
		S) radish_status -follow ;;
		l) radish_list "$OPTARG" ;;
		:)
			case "$OPTARG" in
			l) radish_list ;;
			*)
				echo >&2 "Option -$OPTARG requires an argument"
				usage 1
				;;
			esac
			;;
		\?)
			echo >&2 "Unknown option: -$OPTARG"
			usage 1
			;;
		esac
	done
	shift "$((OPTIND - 1))"
	radish_play "$@"
}

cleanup() {
	rm /tmp/radish.*
}

### "Private" functions

_radish_player() {
	command -v "${1:-}" ||
		command -v "${RADISH_PLAYER:-}" ||
		command -v mpv ||
		command -v vlc ||
		{
			echo >&2 "No suitable player found."
			echo >&2 "Set \$RADISH_PLAYER."
			exit 3
		}
}

_radish_stations() {
	if [ -f "$RADISH_STATION_FILE" ]; then
		sed -e '/^#/d' "$RADISH_STATION_FILE"
	else
		echo noise:
	fi
}

_radish_kill_impl() {
	[ -f "$RADISH_PID_FILE" ] || return 1
	x=
	while xargs -a "$RADISH_PID_FILE" kill 2>/dev/null; do
		case "$x" in
		xxx*)
			printf .
			x=
			;;
		*) x=x$x ;;
		esac
	done
	echo
}

_radish_desc() {
	cut -f2 "${1:--}" 2>/dev/null
}
_radish_url() {
	cut -f1 "${1:--}" 2>/dev/null
}
_radish_tags() {
	cut -f3 "${1:--}" 2>/dev/null
}

_radish_not_running() {
	echo >&2 "Running radish not found."
	exit 2
}

echo() { printf '%s\n' "$*"; }

### Main functionality

radish_kill() {
	if [ -f "$RADISH_PID_FILE" ]; then
		printf >&2 '%s' "Killing radish..."
		_radish_kill_impl
	else
		_radish_not_running
	fi
	cleanup
	exit
}

radish_status() {
	trap 'echo;exit 0' INT
	if [ -n "${1:-}" ]; then
		follow=-f
	else
		follow=
	fi
	tail $follow "$RADISH_STATUS_FILE" 2>/dev/null || _radish_not_running
	echo
	exit
}

radish_list() {
	_radish_stations | grep -i "${1:-}" | awk -F '\t' '{
		desc = $'$_schema_desc'
		url = $'$_schema_url'
		tags = $'$_schema_tags'
		printf "%-23s |", substr(desc,1,20) (length(desc)>20?"...":"")
		printf "%-23s |", substr(tags,1,20) (length(tags)>20?"...":"")
		printf "%-23s\n", substr(url,1,20) (length(url)>20?"...":"")
		}'
	exit
}

radish_choose_station() {
	cands="$(_radish_stations | grep -i "$1")"
	[ -z "$cands" ] && cands="$(_radish_stations)"

	if [ "$(echo "$cands" | wc -l)" -gt 1 ]; then
		echo "$cands" | _radish_desc | cat -n -
		while true; do
			printf "Radish> "
			read station
			if (echo "$station" | grep -qE '^[0-9]+$'); then
				station="$(echo "$cands" | sed -n "${station}p;${station}q")"
				if [ -z "$station" ]; then
					echo >&2 "No station with that number."
					continue
				else
					break
				fi
			fi
			echo >&2 "Please input a station number."
		done
	else
		station="$(echo "$cands")"
	fi
	echo >&2 "Selected: $(echo "$station" | _radish_desc)"
	station="$(echo "$station" | _radish_url)"
}

### Player functions

radish_play() {
	case "${1:-}" in
	https:* | http:*)
		_radish_kill_impl || :
		name="$(grep "$1" "$RADISH_STATION_FILE" | cut -f2)"
		echo >&2 "Streaming ${name:-$1}..."
		radish_play_web "$1"
		;;
	noise:*)
		_radish_kill_impl || :
		echo >&2 "Playing noise: ${1#noise:}"
		radish_play_noise "${1:-}"
		;;
	shuf:*)
		_radish_kill_impl || :
		echo >&2 "Shuffling from ${1#shuf:}"
		SHUF=1 radish_play_file "$1" 2>&1
		;;
	file:*)
		_radish_kill_impl || :
		echo >&2 "Playing from ${1#file:}"
		SHUF=0 radish_play_file "$1" 2>&1
		;;
	*)
		if [ -f "$RADISH_STATION_FILE" ]; then
			radish_choose_station "${1:-}"
			_radish_kill_impl || :
			radish_play "$station"
		else
			_radish_kill_impl || :
			radish_play_noise
		fi
		;;
	esac

	echo "${1:-}" | _radish_url >"$RADISH_LP_FILE"
	exit
}

radish_play_web() {
	"$(_radish_player)" "$1" >"$RADISH_STATUS_FILE" 2>&1 &
	echo $! >"$RADISH_PID_FILE"
}

radish_play_file() {
	dir="$(echo "$1" | sed 's@^[^:]*:\(//\)\?@@')"
	find "$dir" -depth -print0 \
		-iname '*flac' -o \
		-iname '*mp3' -o \
		-iname '*ogg' -o \
		-iname '*opus' |
		xargs -0 realpath |
		case "$SHUF" in
		1) shuf ;;
		0) sort ;;
		esac >/tmp/radish.m3u
	player="$(_radish_player)"
	case "$player" in
	*vlc | *mpv) args="--no-video" ;;
	*) args= ;;
	esac
	"$player" $args /tmp/radish.m3u "$1" >"$RADISH_STATUS_FILE" 2>&1 &
	echo $! >"$RADISH_PID_FILE"
}

radish_play_noise() {
	# REQUIRES PLAY (from SOX) -- based on https://gist.github.com/rsvp/1209835
	play="$(command -v play)" || {
		echo >&2 "Noise playback requires sox(1)."
		exit 3
	}
	# URL format: noise:type/center?time=60;wave=0.033;volume=1
	url_format='noise:\([^/]\+\)/\([^?]\+\)?\(.*\)'
	noise_type="$(echo "${1:-}" | sed -n "s@${url_format}@\1@")"
	noise_center="$(echo "${1:-}" | sed -n "s@${url_format}@\2@")"
	noise_params="$(echo "${1:-}" | sed -n "s@${url_format}@\3@")"
	time=60
	wave=0.03333333
	volume=1
	if [ -z "$noise_type" ] && [ -z "$noise_center" ]; then
		noise_type=brown
		noise_center=1786
	elif [ -z "$noise_type" ] || [ -z "$noise_center" ]; then
		echo >&2 "URL format: 'noise:TYPE/CENTER?[PARAMS]"
		echo >&2 "TYPE is one of 'brown','white','pink','tpdf'."
		echo >&2 "CENTER is the center of the band-pass filter."
		echo >&2 "PARAMS are TIME to generate noise;"
		echo >&2 "WAVE, denoting volume variation; and VOLUME."
		exit 4
	else
		eval "$noise_params"
	fi

	export RADISH_PLAYER=play
	echo >&2 "$(_radish_player)" \
		-c 2 --null synth "$time" "${noise_type}noise" \
		band -n "$noise_center" 499 \
		tremolo "$wave" 43 reverb 19 \
		bass -11 treble -1 \
		vol 14dB vol "$volume" \
		repeat "$(expr $time - 1)"
	"$(_radish_player)" \
		-c 2 --null synth "$time" "${noise_type}noise" \
		band -n "$noise_center" 499 \
		tremolo "$wave" 43 reverb 19 \
		bass -11 treble -1 \
		vol 14dB vol "$volume" \
		repeat "$(expr $time - 1)" >"$RADISH_STATUS_FILE" 2>&1 &
	echo $! >"$RADISH_PID_FILE"
}

main "$@"