timer demo

shopt -s checkwinsize # for COLUMNS

# Requires bash-boost: https://github.com/tomocafe/bash-boost
source "$HOME/bash-boost/latest/bash-boost.sh"

bb_load cli util

bb_setprog "timer"
bb_addopt H:hours "Hours" 0
bb_addopt M:mins "Minutes" 0
bb_addopt S:secs "Seconds" 0
bb_addopt red "Make display red at R seconds remaining (default: 10)" 10
bb_addopt yellow "Make display yellow at Y seconds remaining (default: 60)" 60
bb_addopt F:timefmt "Time format (default: %H:%M:%S)" "%H:%M:%S"
bb_addopt i:interval interval 1
bb_parseargs "$@"

bb_getopt -v h hours
bb_getopt -v m mins
bb_getopt -v s secs
bb_getopt -v interval interval
bb_getopt -v red red
bb_getopt -v yellow yellow
bb_getopt -v fmt timefmt

countdown=$(( h*3600 + m*60 + s ))
[[ $countdown -gt 0 ]] || exit 0

bb_info "Countdown will complete at $(bb_timefmt "%F %T" $(bb_now "+${countdown}s"))"

while [[ $countdown -gt 0 ]]; do
    # convert countdown seconds to time string
    TZ= printf -v text "%($fmt)T" $countdown
    # center the uncolored time string
    bb_centerstr -v line $COLUMNS "$text"
    # determine color, then add color to the time string
    color="green"
    if [[ $countdown -le $red ]]; then
        color="red"
    elif [[ $countdown -le $yellow ]]; then
        color="yellow"
    fi
    colortext="$(bb_rawcolor "$color" "$text")"
    # replace uncolored centered text with colored text, print it on the existing line
    printf "\r%s" "${line/$text/$colortext}"
    # sleep based on interval
    bb_min -v i $countdown $interval
    (( countdown -= i ))
    sleep "$i"
done

trap "echo" EXIT # make sure we finish the line