#!/bin/bash
first_be_sure="First be sure that the USB device to backup to is connected now"
no_config="There is no configuration file. Let's create it. Choose the USB device that will trigger the backup"
devices="Devices"
select_path="Select the path in the disk (must be mounted) to place the backup"
select_folder="Select the folder to backup"
encrypt="Do you want to encrypt the backups? (Recommended)"
initializing="Initializing repository"
backing_up="Backing up"
to="to"
there_was_error="There was an error"
backup_succeeded="Backup finished without errors.\n Result: "
doing_backup="doing the backup"
initializing_low="initializing repository"
waiting="Waiting another 3 seconds"
waited="Waited for 60 seconds for the destination to be available without sucess. Check your configuration and that the destination folder exists"
another_copy="There is another copy running"
reconfigure_help="Reconfigure the script"
help="Show this help"
function usage() {
    echo "${script_name} [-r|--reconfigure] [-h|--help]"
    echo "    -r|--reconfigure ${reconfigure_help}"
    echo "    -h|--help        ${help}"
}
function configure() {
    zenity --info --text "${first_be_sure}"
    # shellcheck disable=SC2046
    device=$(zenity --list --text="${no_config}" --column="${devices}" --separator='\n' $(lsusb | sed 's/.* ID //g' | sed 's/ /_/g'))
    echo "device='${device}'" > "${HOME}/.config/simple_backup.conf"
    zenity --info --text "${select_path}"
    destination=$(zenity --file-selection --directory)
    echo "destination='${destination}'" >> "${HOME}/.config/simple_backup.conf"
    zenity --info --text "${select_folder}"
    folder=$(zenity --file-selection --directory)
    echo "folder='${folder}'" >> "${HOME}/.config/simple_backup.conf"
    if zenity --question --text "${encrypt}"; then
        password=$(zenity --password)
        echo "${password}" > "${HOME}/.config/simple_backup.password"
        chmod go-rwx "${HOME}/.config/simple_backup.password"
    else
        rm "${HOME}/.config/simple_backup.password"
    fi
}
script_dir=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
script_name=$(basename "${BASH_SOURCE[0]}")

# shellcheck disable=SC2001
locale=$(echo "${LANG}" | sed 's/\..*$//')
if [ -e "${script_dir}/locales/${locale}" ]; then
    # shellcheck disable=SC1090
    source "${script_dir}/locales/${locale}"
fi

while [ ${#} -gt 0 ]
do
    case "${1}" in
        "-h"|"--help")
            usage
            shift
            exit 0
            ;;
        '-r'|'--reconfigure')
            shift
            configure
        ;;
        *)
            echo "Ignoring unknown parameter '${1}'"
            shift
            ;;
    esac
done

if [ ! -r "${HOME}/.config/simple_backup.conf" ]; then
    configure
fi

if [ ! -x /usr/local/bin/restic ]; then
    if [ "$(uname -i)" == 'x86_64' ]; then
        arch="amd64"
    elif [[ "$(uname -a)" =~ aarch64 ]]; then
        arch='arm64'
    fi
    /usr/bin/wget -q -O - "$(/usr/bin/curl -s -L -H 'Accept: application/vnd.github+json' -H 'X-GitHub-Api-Version: 2022-11-28' https://api.github.com/repos/restic/restic/releases/latest | jq ".assets[]|select(.browser_download_url|contains(\"${arch}\"))|.browser_download_url" | sed 's/\"//g')" | bzip2 -dc > /usr/local/bin/restic
    chmod +x /usr/local/bin/restic
fi

if [ $(pgrep -f -c "${script_name}") -gt 1 ]; then
    echo "${another_copy}"
    exit 3
fi

# shellcheck disable=SC1091
source "${HOME}/.config/simple_backup.conf"

if [ -r "${HOME}/.config/simple_backup.password" ]; then
    password_file=(--password-file "${HOME}/.config/simple_backup.password")
else
    password_file=()
fi

mkdir -p "${HOME}/.logs"

vendor="${device:0:4}"
product_id="${device:5:4}"
if [ ! -e /etc/udev/rules.d/10_simple_backup.rules ]; then
    sudo touch /etc/udev/rules.d/10_simple_backup.rules
    echo "SUBSYSTEM==\"usb\" ACTION==\"add\" ATTRS{idVendor}==\"${vendor}\" ATTRS{idProduct}==\"${product_id}\" ATTR{partscan}==\"1\" TAG+=\"systemd\" ENV{SYSTEMD_USER_WANTS}=\"simple_backup@\$devnode.service\"" | sudo tee /etc/udev/rules.d/10_simple_backup.rules
fi
if [ ! -e "${HOME}/.config/systemd/user/simple_backup@.service" ]; then
    mkdir -p "${HOME}/.config/systemd/user/"
    cat << EOF > "${HOME}/.config/systemd/user/simple_backup@.service"
[Unit]
Description=Simple backup USB serial device at %I

[Service]
Type=simple
ExecStart=bash -c 'sleep \$((1 + \$RANDOM % 10)); ${script_dir}/${script_name} %IEOF'
EOF
    systemctl --user daemon-reload
    systemctl --user enable simple_backup@.service
fi

if [ ! -e "${destination}" ]; then
    count=0
    while [ ! -e "${destination}" ]
    do
        sleep 3
        echo "${waiting}"
        count=$((count + 1))
        if [ ${count} -gt 20 ]; then
            zenity --error --text "${waited}"
            exit 2
        fi
    done
fi
if [ ! -e "${destination}/config" ]; then
    echo "${initializing} '${destination}'..."
    if ! /usr/local/bin/restic init "${password_file[@]}" -r "${destination}"; then
        zenity --error --text "${there_was_error} ${return_code} ${initializing_low}"
        exit 1
    fi
fi
echo "${backing_up} '${folder}' ${to} '${destination}'..."
current_date=$(date +%Y.%m.%d_%H_%M_%S)
/usr/local/bin/restic backup "${password_file[@]}" -r "${destination}" "${folder}" --json > "${HOME}/.logs/simple_backup_${current_date}.json"
return_code=${?}
cp "${HOME}/.logs/simple_backup_${current_date}.json" "${HOME}/.logs/simple_backup_last.json" -f
if [ "${return_code}" != "0" ]; then
    zenity --error --text "${there_was_error} ${return_code} ${doing_backup}"
else
    result=$(tail -n1 "${HOME}/.logs/simple_backup_${current_date}.json" | jq '.')
    zenity --info --text "${backup_succeeded} ${result}"
fi