Syncplay<->IRC bridge

bridge.sh

#!/usr/bin/env bash
# dependencies: bash 4+, jq

. ./config.sh
: "${verbose:=0}"
: "${syncplay_host:=syncplay.pl}"
: "${syncplay_port:=8999}"
: "${syncplay_nick:=syncplaybridge}"
: "${syncplay_room:?"can't be empty"}"
: "${irc_host:=chat.freenode.net}"
: "${irc_port:=6667}"
: "${irc_nick:=syncplaybridge}"
: "${irc_channel:?"can't be empty"}"

irc_send() {
    local args=("$@")
    args[0]=${args[0]^^}
    if (( ${#args[@]} > 1 )); then
        args[${#args[@]}-1]=:${args[${#args[@]}-1]}
    fi
    printf '%s\r\n' "${args[*]}" >&"$irc_fd"
    (( verbose )) && printf 'IRC %s==>%s %s\n' "$(tput setaf 1)" "$(tput sgr0)" "${args[*]}" >&2
}

irc_say() {
    irc_send privmsg "$irc_channel" "$*"
}

irc_ctcp() {
    local args=("$@")
    args[0]=${args[0]^^}
    irc_send notice "$sender_nick" $'\1'"${args[*]}"$'\1'
}

syncplay_send() {
    local msg=$(jq -nc "$@")
    printf '%s\r\n' "$msg" >&"$syncplay_fd"
    (( verbose )) && printf 'syncplay %s==>%s %s\n' "$(tput setaf 1)" "$(tput sgr0)" "$msg" >&2
}

syncplay_say() {
    syncplay_send --arg message "$*" '{Chat: $message}'
}

on_exit() {
    irc_send quit
    kill $(jobs -p)
}

exec {irc_fd}<> /dev/tcp/"$irc_host"/"$irc_port" || exit
exec {syncplay_fd}<> /dev/tcp/"$syncplay_host"/"$syncplay_port" || exit

trap on_exit exit

irc_send nick "$irc_nick"
irc_send user "$irc_nick" 0 '*' 'Syncplay<->IRC'

syncplay_send --arg username "$syncplay_nick" --arg room "$syncplay_room" \
    '{Hello: {$username, room: {name: $room}, realversion: "1.6.5"}}'

while read -ru "$irc_fd" line; do
    line=${line%$'\r'}
    (( verbose )) && printf 'IRC %s<==%s %s\n' "$(tput setaf 2)" "$(tput sgr0)" "$line" >&2
    sender= sender_nick=
    args=()
    if [[ $line == :* ]]; then
        sender=${line%% *}
        sender=${sender#:}
        sender_nick=${sender%%!*}
        line=${line#* }
    fi
    while [[ $line == *' '* && $line != :* ]]; do
        args+=("${line%% *}")
        line=${line#* }
    done
    args+=("${line#:}")
    cmd=${args[0]}
    set -- "${args[@]:1}"
    case ${cmd,,} in
        001) irc_send join "$irc_channel";;
        ping) irc_send pong "$1";;
        privmsg)
            target=$1
            message=$2
            if [[ $target == "$irc_nick" ]] && [[ $message =~ ^$'\1'(.*)$'\1'$ ]]; then
                message=${BASH_REMATCH[1]}
                read -r ctcp_cmd _ <<< "$message"
                case ${ctcp_cmd,,} in
                    version) irc_ctcp version "syncplaybridge";;
                esac
            elif [[ $target == "$irc_channel" ]]; then
                if [[ $message =~ ^$'\1ACTION '(.*)$'\1'$ ]]; then
                    syncplay_say "* $sender_nick ${BASH_REMATCH[1]}"
                else
                    syncplay_say "<$sender_nick> $2"
                fi
            fi
    esac
done &

while read -ru "$syncplay_fd" line; do
    line=${line%$'\r'}
    (( verbose )) && printf 'syncplay %s<==%s %s\n' "$(tput setaf 2)" "$(tput sgr0)" "$line" >&2
    . <(jq <<< "$line" -r --arg self "$syncplay_nick" '
        def irc($msg): @sh "irc_say \($msg)";
        (.State // empty
            | @sh "syncplay_send \"{State: {}}\""),
        (.Chat // empty
            | select(.username != $self)
            | irc("<\(.username)> \(.message)")),
        (.Set // empty
            | .user // empty
            | keys[0] as $nick
            | .[$nick]
            | (
                (.event // empty
                    | irc("\($nick) \(if .joined then "joined" else "left" end)")),
                (.file // empty
                    | irc("\($nick) is now playing \(.name)"))
            )
        )
        ')
done &

wait