fisher/functions/spin.fish

function spin -d "Background job spinner"
    set -l format "  @\r"
    set -l commands
    set -l spinners "⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏"
    set -l error /dev/stderr

    getopts $argv | while read -l 1 2
        switch "$1"
            case _
                set commands $commands ";$2"

            case s style
                set spinners $2

            case f format
                set format $2

            case error
                set error $2

            case h help
                printf "Usage: spin <commands> [--style=<style>] [--format=<string>] \n"
                printf "                       [--error=<file>] [--help]\n\n"

                printf "    -s --style=<string>   Use <string> to slice the spinner characters\n"
                printf "    -f --format=<format>  Use <format> to customize the spinner display\n"
                printf "        --error=<file>    Write errors to <file>\n"
                printf "     -h --help  Show usage help\n"
                return

            case \*
                printf "spin: '%s' is not a valid option\n" $1 > /dev/stderr
                spin -h > /dev/stderr
                return 1
        end
    end

    if not set -q commands[1]
        return 1
    end

    set spinners (printf "%s\n" "$spinners" | grep -o .)

    set -l tmp (mktemp -t spin.XXX)
    set -l job_id

    fish -c "$commands" > /dev/stdout ^ $tmp &

    set job_id (jobs -l | cut -d\t -f1)

    while contains -- $job_id (jobs | cut -d\t -f1 ^ /dev/null)
        if status --is-interactive
            for i in $spinners
                printf "$format" | awk -v i=(printf "%s\n" $i | sed 's/=/\\\=/') '
                {
                    gsub("@", i)
                    printf("%s", $0)
                }
                ' > /dev/stderr

                sleep 0.01
            end
        end
    end

    if test -s $tmp
        command cat $tmp > $error
        command rm -f $tmp
        return 1
    end

    command rm -f $tmp
end