Twitch.tv desktop notification bash script

twitch-notify.sh

#!/bin/bash

# twitch-notify.sh by Alex Baines
#	Desktop notifications about twitch.tv streams.
# dependencies:
#	curl
#	underscore-cli
#	notify-send
#	md5sum

# user-agent sent to twitch.
ua="twitch-notify.sh"

# put lowercase channel names, one per line, in this file.
infile="twitch-channels.txt"

# this file will be kept up-to-date with a list of online streams.
outfile="twitch-status.txt"

# directories for temporary files.
tmpbase="/tmp/twitch"
tmpimgdir="$tmpbase/imgs"

# sounds to play when the status of a stream changes.
new_stream_snd=""
upd_stream_snd=""
del_stream_snd=""

# command to play sounds.
play_snd_cmd="paplay"

# read new stream notifications out loud with espeak or not.
use_espeak=1

# update rate in seconds.
interval=300

declare -A online

function get_img_path {
	echo ${tmpimgdir}"/"$(md5sum <<<"$1" | cut -d\  -f 1)
}

function add_stream {
	local img=$(get_img_path "$1")
	
	if [ "$4" == "null" ]; then
		img="video-x-generic"
	else
		curl -s -A "$ua" "$4" -o "$img"
	fi
	
	notify-send -i "$img" "$1 is streaming now." "$2 [$3]"
	
	if [ -n "$play_snd_cmd" -a -n "$new_stream_snd" ]; then
		$play_snd_cmd "$new_stream_snd" &
	fi
	
	if [ $use_espeak ]; then
		echo "$1 - $3" | espeak 2>/dev/null
	fi
	
	online[$1]="\"$2\"\n\t[$3]"
}

function del_stream {
	local img=$(get_img_path "$1")
	
	notify-send -i "$img" "$1 is no longer streaming."
	
	if [ -n "$play_snd_cmd" -a -n "$del_stream_snd" ]; then
		$play_snd_cmd "$del_stream_snd" &
	fi

	rm "$img"
	
	unset online[$1]
}

function upd_stream {
	local img=$(get_img_path "$1")

	notify-send -i "$img" "$1 changed game." "Now streaming $2. [$3]"
	
	if [ -n "$play_snd_cmd" -a -n "$upd_stream_snd" ]; then
		$play_snd_cmd "$upd_stream_snd" &
	fi
	
	online[$1]="\"$2\"\n\t[$3]"
}

function writefile {
	echo -e "Last Update: $(date)\n------------\n">"$outfile"
	for i in "${!online[@]}" ; do
		echo -e "$i:\n\t${online[$i]}\n" >> "$outfile"
	done
}

function contains {
  local e
  for e in "${@:2}"; do [[ "$e" == "$1" ]] && echo "true"; done
  echo "false"
}

function dl {
	curl -A "$ua" -s -w "%{http_code}" -o /dev/stderr "https://api.twitch.tv/kraken/streams?channel=$chans"
}

[ -d "$tmpbase" ] || mkdir "$tmpbase"
[ -d "$tmpimgdir" ] || mkdir "$tmpimgdir"

while true; do
	t=$(date +%s)
	
	chans=$(tr "\n" "," <"$infile")
	unset t_out t_err
	
	#ugly hack to get both stdout and stderr from curl
	eval "$( (dl) 2> >(readarray -t t_err; typeset -p t_err) > >(readarray -t t_out; typeset -p t_out) )"
	js="$t_err"
	if [[ "$t_out" == "200" ]]; then
	
		js2=$(underscore --coffee process "data.streams.map (x) -> {"`
		`"n: x.channel.name,"`
		`"g: x.channel.game || x.game || 'null',"`
		`"s: x.channel.status || 'null',"`
		`"l: x.channel.logo || 'null' }" <<<"$js")
		
		underscore pretty <<< "$js2"

		# the Twitch API likes to lie and return 0 results sometimes, try to filter them out.
		
		if [[ "$js2" == "[ ]" && "${#online[@]}" > 1 && -z "$twitch_lies" ]]; then
			echo "Skipping potentially erroneous update..."
			twitch_lies=1
			d=$(($(date +%s)-$t))
			if [ "$d" -lt "$interval" ] ; then
				sleep $(($interval-$d))
			fi
			continue
		fi
		
		unset twitch_lies
			
		IFS=$'\n'
		names=($(underscore select '.n' --outfmt text <<< "$js2"))
		games=($(underscore select '.g' --outfmt text <<< "$js2"))
		logos=($(underscore select '.l' --outfmt text <<< "$js2"))
		statuses=($(underscore select '.s' --outfmt text <<< "$js2"))
		
		unset $IFS
	
		for x in "${!online[@]}"; do
			if [ "$(contains $x ${names[@]})" == "false" ]; then
				del_stream "$x"
			fi
		done

		for ((x=0; x<${#names[@]}; x++)); do
			n="${names[$x]}"
			g="${games[$x]}"
			l="${logos[$x]}"
			s="${statuses[$x]}"
		
			if [[ -z "${online[$n]}" ]]; then
				add_stream "$n" "$s" "$g" "$l"
			elif [[ "$s" != "null" && "${online[$n]}" != "\"$s\"\n\t[$g]" ]]; then
				upd_stream "$n" "$s" "$g"
			fi
		done
		writefile
	else
		echo "$0: HTTP error: $t_out."
	fi
	
	d=$(($(date +%s)-$t))
	if [ "$d" -lt "$interval" ] ; then
		sleep $(($interval-$d))
	fi
done