#!/bin/bash

NC='\033[0m'
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'

msg_info() {
    echo -e "${GREEN}$1${NC}"
}

msg_warn() {
    echo -e "${YELLOW}$1${NC}"
}

msg_error() {
    echo -e "${RED}$1${NC}"
}

print_help() {
    echo
    echo "trans - a wrapper for transmission-daemon and transmission-remote"
    echo
    echo "USAGE:"
    echo "    trans COMMAND [...]"
    echo
    echo "COMMANDs are:"
    echo "    ls | list:"
    echo "        list current torrents"
    echo "    start:"
    echo "        start Transmission daemon (if not yet started). The script"
    echo "        won't start the daemon is there is no connection to a VPN"
    echo "        (in this case Mullvad). Use '-f|--force' to start anyway."
    echo "    stop:"
    echo "        stop Transmission daemon"
    echo "    add:"
    echo "        add a sequence of torrent files or a single magnet link"
    echo "        (possibly a bug with transmission-remote). If no torrent is"
    echo "        specified the current selection in the clipboard is used as a"
    echo "        torrent/magnet link"
    echo "    rm | remove:"
    echo "        remove a list of torrents. The syntax is the same as the one for"
    echo "        the '--torrent' option in the 'transmission-remote' command. A"
    echo "        special token 'complete' can be provided to remove all completed"
    echo "        torrents. If no torrent is specified no action is performed."
    echo "    del | delete:"
    echo "        remove a list of torrents and deletes the corresponding files."
    echo "        The syntax is the same as the one for the '--torrent' option in"
    echo "        the 'transmission-remote' command. If no torrent is specified no"
    echo "        action is performed."
    echo "    pause:"
    echo "        pause a list of torrents. The syntax is the same as the one for"
    echo "        the '--torrent' option in the 'transmission-remote' command. If"
    echo "        no list is provided the token 'all' is assumed"
    echo "    unpause:"
    echo "        unpause a list of torrents. The syntax is the same as the one for"
    echo "        the '--torrent' option in the 'transmission-remote' command. If no"
    echo "        list is provided the token 'all' is assumed"
    echo "    info:"
    echo "        print detailed information on a list of torrents. The syntax is"
    echo "        the same as the one for the '--torrent' option in the"
    echo "        'transmission-remote' command. If no list is provided the token"
    echo "        'all' is assumed"
    echo "    help:"
    echo "        print this help"
    echo
}

transmission_start() {
    pgrep transmission-da >/dev/null &&
        error "Transmission daemon is already running!" ||
        transmission-daemon "$@"
}

COMMAND=${1:-list}
shift

case $COMMAND in
    ls|list)
        transmission-remote --list
        ;;
    start)
        # Checking VPN connection
        echo "Checking Mullvad status..."
        mullvad status &>/dev/null
        vpn=$?
        # Collect additional flags
        force=0
        case $1 in
            -f|--force)
                # Force run even if not connected to a VPN
                force=1
                ;;
        esac
        echo $vpn
        echo $force
        if [[ $vpn -gt 0 ]]; then
            warning="You are not connected to a VPN..."
            msg_warn "$warning"
            if [[ $force -gt 0 ]]; then
                msg_warn "...starting Transmission daemon anyway!"
                transmission_start
            else
                notify-send --urgency=critical "Transmission" "$warning"
                msg_warn "Use -f|--force to start the Transmission daemon anyway."
                exit 2
            fi
        else
            msg_info "Starting Transmission daemon..."
            transmission_start
        fi
        ;;
    stop)
        msg_info "Stopping Transmission daemon..."
        transmission-remote --exit
        exit $?
        ;;
    add)
        [[ $# -ge 1 ]] &&
            transmission-remote --add "$@" ||
            transmission-remote --add $(xclip -o -selection clipboard)
        ;;
    rm|remove)
        if [[ $# -ge 1 ]]; then
            [[ $1 == "complete" ]] &&
                t=$(transmission-remote --list | grep 100% | grep Done | awk '{ print $1 }' | paste -sd, -) ||
                t=$@
            [[ -z $t ]] && msg_warn "No completed torrent to remove." && exit 0
            transmission-remote -t"$t" --remove
        fi
        ;;
    del|delete)
        [[ $# -ge 1 ]] && transmission-remote -t"$@" --remove-and-delete
        ;;
    pause)
        transmission-remote -t${@:-all} --stop
        ;;
    unpause)
        transmission-remote -t${@:-all} --start
        ;;
    info)
        transmission-remote -t${@:-all} --info
        ;;
    help)
        print_help
        ;;
    *)
        msg_error "$COMMAND: invalid command"
        print_help
        exit 1
        ;;
esac

exit 0