#!/usr/bin/env bash

# Author        : Allan Christensen
# First Created : 08042022 (DD-MM-YYYY)
# Description   : Installs Certbot with Cloudflare and Dns Challenge on Ubuntu 24.04
# License       : MIT License (see LICENSE file for details)

#
# Are we root
#
if [[ $(id -u) -ne 0 ]]; then echo "" && echo "Must be root or use sudo" && echo "" ; exit ; fi

#
# If snap is not installed then die
#
if ! command -v snap >/dev/null 2>&1; then echo "ERROR: snap is not installed aborting" ; exit 1 ; fi

#
# Function usage
#
usage () {
printf -- "\ncertbotinstall\n\n"
printf -- "Note: Must be run as root or using sudo\n\n"
printf -- "Usage:\n"
printf -- "sudo ./certbotinstall [-p] <API Token>\n"
printf -- "                      [-h] <this screen>\n\n"
printf -- "Examples:\n"
printf -- "sudo ./certbotinstall -p 1234AkkbdceewEFJK\n\n"
}

#
# Let's go
#
clear


#
# Check if no arguments were given
#
if [[ $# -eq 0 ]]; then usage; exit 1; fi

#
# Manual argument parsing
#
while [[ $# -gt 0 ]]; do
    case "$1" in
        -p)
            shift
            if [[ -z "$1" ]]; then
                usage
                printf "ERROR: API TOKEN CANNOT BE EMPTY!\n\n"
                exit 1
            fi
            apitoken="$1"

            #
            # Validate Cloudflare API token format
            #
            if [[ "$apitoken" =~ [[:space:]] ]]; then
                printf "\nERROR: API token cannot contain spaces or line breaks.\n\n"
                exit 1
            fi

	    if [[ ! "$apitoken" =~ ^[A-Za-z0-9_-]{20,120}$ ]]; then
    	    	printf "\nERROR: Invalid API token format.\n"
            	printf "Expected 20-120 characters (A-Z, a-z, 0-9, - or _).\n\n"
            	exit 1
            fi

            shift
            ;;
        -h)
            usage
            exit 0
            ;;
        *)
            usage
            printf "\nType: sudo %s -h for help\n\n" "$0"
            exit 1
            ;;
    esac
done

#
# Install Certbot
#
snap install core && snap refresh core
snap install --classic certbot
ln -sf /snap/bin/certbot /usr/bin/certbot

#
# Install Cloudflare plugin 
#
snap set certbot trust-plugin-with-root=ok
snap install certbot-dns-cloudflare

#
# Create the directory and the file that will store the api token
#
mkdir -p /etc/letsencrypt
cat > /etc/letsencrypt/dnscloudflare.ini <<EOT
# Cloudflare API token used by Certbot
dns_cloudflare_api_token = $apitoken
EOT
chmod 0600 /etc/letsencrypt/dnscloudflare.ini

#
# All done
#
printf "\nAll Done...\n\n"

#
# End of script
#