#!/bin/bash

SERIAL=/dev/ttyUSB0

VOLUME_CONTROL="Line Out"

RADIO1_URL="http://us2.internet-radio.com:8443/stream"
RADIO2_URL="https://rozhlas.stream/ddur_mp3_128.mp3"
RADIO3_URL="https://rozhlas.stream/brno_mp3_128.mp3"
#https://rozhlas.stream/radiozurnal_aac_128.aac
RADIO4_URL="https://ice3.abradio.cz/croretro128.mp3"

killStream() {
	kill `ps aux | grep "$1" | awk '{print $2}'` 2>/dev/null
}

playStream() {
	mplayer "$1" </dev/null >/dev/null 2>&1 &
}

handleStream() {
	STREAM=$1
	STATE=$2
	#killStream "$STREAM"
	if [ $STATE = 1 ]; then
		playStream "$STREAM"
		echo "Started radio: $STREAM"
	else
		echo "Stopped radio: $STREAM"
	fi
}

execVolume() {
	VOLUME_RAW=`echo "scale=4; $1/255*100" | bc`
	VOLUME=`printf "%.0f%%" "$VOLUME_RAW"`
	amixer sset "$VOLUME_CONTROL" "$VOLUME" >/dev/null &
	echo Volume set to $VOLUME
	#echo Volume set to $1
}


execButton() {
	case $1 in
		1)
			handleStream "$RADIO1_URL" "$2"
			;;
		2)
			handleStream "$RADIO2_URL" "$2"
			;;
		3)
			handleStream "$RADIO3_URL" "$2"
			;;
		4)
			handleStream "$RADIO4_URL" "$2"
			;;
		*)
			echo "Unknown button '$1'." >&2
			;;
	esac
}

process_event() {
	case $1 in
		volume)
			execVolume "$2"
			;;

		button*)
			NUM=`echo $1 | tr -dc [:digit:]`
			execButton "$NUM" "$2"
			;;

		"")
			;;

		*)
			echo "Unknown event '$1'." >&2
			;;
	esac
}

consume_events() {
	while true; do
		IFS=$'\r'= read EVENT VALUE
		if [ $? == 0 ]; then
			#echo EVENT: $EVENT = $VALUE
			process_event "$EVENT" "$VALUE"
		else
			echo Invalid input. >&2
		fi
	done
}

stty -F $SERIAL 9600 cs8 -cstopb -parenb
cat $SERIAL | consume_events