# -*- sh-shell: bash -*-
# shellcheck shell=bash
if [ -z ${_LIBDEMO_INC+x} ]; then
    _LIBDEMO_INC=true
    prev=
    use_colour() {
        if [ "${LIBDEMO_USE_COLOUR:-}" = 1 ]; then
            return 0
        elif [ "${LIBDEMO_USE_COLOUR:-}" = 0 ]; then
            return 1
        elif [ "${CLICOLOR_FORCE:-}" = 1 ]; then
            return 0
        elif [ "${CLICOLOR_FORCE:-}" = 0 ]; then
            return 1
        elif [ "${TERM:-}" = dumb ]; then
            return 1
        elif [ -t "${1:-1}" ]; then
            return 0
        else
            return 1
        fi
    }
    use_unicode() {
        if [ "${LIBDEMO_USE_UNICODE:-}" = 1 ]; then
            return 0
        elif [ "${LIBDEMO_USE_UNICODE:-}" = 0 ]; then
            return 1
        elif [ "${TERM:-}" = dumb ]; then
            return 1
        else
            return 0
        fi
    }
    demopause() {
        if [ "${LIBDEMO_INTERACTIVE:-1}" = 1 ]; then
            read -n 1 -s -r -p ""
        fi
    }
    demoheader() {
        local prefix
        echo
        if use_unicode; then
            if use_colour; then
                prefix="\e[1;34m[#]\e[0m"
            else
                prefix="[#]"
            fi
        else
            if use_colour; then
                prefix="\e[1;34m # \e[0m"
            else
                prefix=" # "
            fi
        fi
        if use_colour; then
            echo -e "${prefix}\e[1m" "$@" "\e[0m"
        else
            echo -e "${prefix}" "$@"
        fi
        prev=demoheader
    }
    h() {
        demoheader "$@"
    }
    demoecho() {
        if [ "${prev}" != demoecho ]; then
            echo
        fi
        local prefix
        prefix="   "
        echo -e "${prefix}" "$@"
        prev=demoecho
    }
    ,() {
        demoecho "$@"
    }
    democmd() {
        echo
        local prefix
        if use_unicode; then
            if use_colour; then
                prefix="\e[1;35m[\xE2\x9F\xB6]\e[0m"
            else
                prefix="[\xE2\x9F\xB6]"
            fi
        else
            if use_colour; then
                prefix="\e[1;35m[>]\e[0m"
            else
                prefix="[>]"
            fi
        fi
        if use_colour; then
            echo -e "${prefix}\e[1m" "$@" "\e[0m"
        else
            echo -e "${prefix}" "$@"
        fi
        echo
        demopause
        if $@; then
            if [ "${expect}" != 0 ]; then
                return 1
            fi
            if use_unicode; then
                if use_colour; then
                    prefix="\e[0;32m[\xE2\x9C\x93]\e[0m"
                else
                    prefix="[\xE2\x9C\x93]"
                fi
            else
                if use_colour; then
                    prefix="\e[0;32m[+]\e[0m"
                else
                    prefix="[+]"
                fi
            fi
        else
            if [ "${expect}" = 0 ]; then
                return 1
            fi
            if use_unicode; then
                if use_colour; then
                    prefix="\e[0;31m[\xE2\x9C\x97]\e[0m"
                else
                    prefix="[\xE2\x9C\x97]"
                fi
            else
                if use_colour; then
                    prefix="\e[0;31m[ error ]\e[0m"
                else
                    prefix="[ error ]"
                fi
            fi
        fi
        # echo -e "${prefix}"
        demopause
        prev=democmd
    }
    x() {
        expect=0
        democmd "$@"
    }
    f() {
        expect=1
        democmd "$@"
    }
fi

# nix-container-demo
Scripts to (interactively) demonstrate capabilities of Nix.

#!/usr/bin/env bash
set -Eeuo pipefail
source "$(dirname "${BASH_SOURCE[0]}")/../bash/libdemo.sh"
h Getting the weather
, With Docker we might use \'docker run curlimages/curl wttr.in/Delft\'\; with Nix we can use
# x nix run nixpkgs#curl -- wttr.in/Delft
x nix run nixpkgs#curl -- --version
h But we may already have had curl on our path?
x type curl
h So to prove \'nix run\' works:
f type cowsay
x nix run nixpkgs#cowsay -- -f tux hello