#
# returns the absolute value of the difference between two times
#
# assumes the times are on the same day
# expects times in 24-hour format either HH:MM or H:MM
# output is in this same format
#

source ~/lib/sh/include
require time_t_to_readable

time_delta ()
{
        local -a time
        local +i i
        local +i delta

        (($# == 2)) || {
                echo "$FUNCNAME: needs two times in HH:MM or H:MM format"
                return 1
        }

        for ((i = 1; i <= 2; i++)); do
                time=$1
                [[ $time =~ '([[:digit:]]{1,2}):([[:digit:]]{2})' ]]
                time[i]=$((${BASH_REMATCH[1]#0} * 60
                           + ${BASH_REMATCH[2]#0})) # minutes
                shift
        done

        if ((time[1] > time[2])); then
                delta=$((time[1] - time[2]))
        else
                delta=$((time[2] - time[1]))
        fi

        ((delta *= 60)) # make seconds

        fsetvar delta time_t_to_readable $delta
        freturn $delta
}
# vim:syn=sh:ft=sh