getopts for bash example with 4 inputs expected

quality_events.bash

#!/usr/bin/env bash
set -e

usage() {
    echo "Usage: $0 -q {high|low} -e {event_ID}" >&2
    exit 1
}

if [ $# -ne 4 ]; then
    usage
fi

while getopts ":q:e:" opt; do
    case "$opt" in
        q)
            IMG_QLTY=${OPTARG}
            test "${IMG_QLTY}" = "high" || test "${IMG_QLTY}" = "low" || usage
            ;;
        e)
            EVENT_ID=${OPTARG}
            [[ ${EVENT_ID} =~ ^[0-9]{5,}$ ]] || usage
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            usage
            ;;
        :)
            echo "Option -$OPTARG requires an argument." >&2
            usage
            ;;
    esac
done
shift $((OPTIND-1))