#!/usr/bin/env bash
# ------------------------------------------------------------------------------
# Copyright (c) 2013-2026 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# Protected by the BSD3 license. Please read bellow for details.
#
# * Redistribution and use in source and binary forms,
# * with or without modification, are permitted provided
# * that the following conditions are met:
# *
# *   Redistributions of source code must retain the above
# *   copyright notice, this list of conditions and the
# *   following disclaimer.
# *
# *   Redistributions in binary form must reproduce the above
# *   copyright notice, this list of conditions and the following
# *   disclaimer in the documentation and/or other materials
# *   provided with the distribution.
# *
# *   Neither the name of the copyright holder nor the names
# *   of any other contributors may be used to endorse or
# *   promote products derived from this software without
# *   specific prior written permission.
# *
# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# * OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Make non-IT peoples think you're busy doing something hard
# Usage: busy [options] [pattern]
# Options:
#   --delay=<ms> : add a delay between each line output (milliseconds)
#   pattern : the string to search for in the hexdump output (default is "ca fe")
busy()
{
    local pattern="ca fe" delay_ms=0

    local PARSED
    # Short: h, p:, d:
    # Long: help, pattern:, delay:
    PARSED=$(getopt -o hp:d: --long help,pattern:,delay: -n 'busy' -- "$@")
    if [[ $? -ne 0 ]]; then
        disp E "Invalid options, use \"busy --help\" to display usage."
        return 1
    fi
    eval set -- "$PARSED"

    while true; do
        case "$1" in
            -h|--help)
                printf "busy: Monitor /dev/urandom for a specific pattern.\n\n"
                printf "Usage: busy [options] [pattern]\n\n"
                printf "Options:\n"
                printf "\t-h, --help\t\tDisplay this help screen\n"
                printf "\t-p, --pattern PATTERN\tHex pattern to search (default: \"ca fe\")\n"
                printf "\t-d, --delay MS\t\tDelay between matches in milliseconds\n"
                return 0
                ;;
            -p|--pattern)
                pattern="$2"
                shift 2
                ;;
            -d|--delay)
                delay_ms="$2"
                if ! [[ "$delay_ms" =~ ^[0-9]+$ ]]; then
                    disp E "Invalid delay: must be an integer (milliseconds)."
                    return 1
                fi
                shift 2
                ;;
            --)
                shift
                break
                ;;
            *)
                disp E "Invalid option: $1"
                return 1
                ;;
        esac
    done

    # If a pattern was provided as a positional argument (e.g., 'busy "ff 00"'),
    # it is captured here.
    [[ -n "$1" ]] && pattern="$1"

    # Convert milliseconds to seconds for 'sleep'
    local delay_s=$(awk "BEGIN { printf \"%.3f\", $delay_ms / 1000 }")

    # Monitor /dev/urandom
    cat /dev/urandom | hexdump -C | grep --line-buffered "$pattern" | \
        while read -r line; do
            echo "$line"
            [[ $delay_ms -gt 0 ]] && sleep "$delay_s"
        done
}
# ------------------------------------------------------------------------------


# EOF