#!/usr/bin/bash

function dl_debian() {
    local base_url
    local ver="$1" # stable, testing
    case "$ver" in
        stable)
            base_url="http://ftp.tw.debian.org/debian-cd/current-live/amd64/iso-hybrid/"
            ;;
        testing)
            base_url="https://cdimage.debian.org/cdimage/weekly-live-builds/amd64/iso-hybrid/"
            ;;
    esac
    local variant="$2" # gnome, kde, lxde, cinnamon, lxqt, mate, xfxe, standard
    shift;shift

    local dir="/boot/live/${ver}/${variant}"
    mkdir -p "$dir"

    echo -n "Downloading hashsum file... "
    curl -4sSL "${base_url}SHA512SUMS" -o "${dir}/SHA512SUMS.NEW" || {
        echo "failed."
        return 1
    }
    echo done.

    if [[ -f "${dir}/SHA512SUMS" ]]; then
        if cmp -s "${dir}/SHA512SUMS" "${dir}/SHA512SUMS.NEW"; then
            echo "No new image found."
            rm -f "${dir}/SHA512SUMS.NEW"
            return 0
        fi
    fi

    local fn="$(grep "amd64-${variant}\\.iso\$" "${dir}/SHA512SUMS.NEW" | awk '{print $2}')"

    wget -c -4O "${dir}/${fn}" "${base_url}${fn}" || {
        echo "Download failed."
        rm -f "${dir}/SHA512SUMS.NEW"
        return 1
    }

    echo -n "Verifying checksum... "
    (cd "$dir" && sha512sum -c --ignore-missing SHA512SUMS.NEW) > /dev/null 2>&1 || {
        echo "failed."
        return 1
    }
    echo done.

    (
        cd "$dir"
        echo -n "Extracting kernel... "
        7z x -aoa "$fn" "live/vmlinuz" > /dev/null 2>&1 || {
            echo "failed."
            return 1
        }
        echo done.

        echo -n "Extracting initrd... "
        7z x -aoa "$fn" "live/initrd.img" > /dev/null 2>&1 || {
            echo "failed."
            return 1
        }
        echo done.

        echo -n "Extracting filesystem... "
        7z x -aoa "$fn" "live/filesystem.squashfs" > /dev/null 2>&1 || {
            echo "failed."
            return 1
        }
        echo done.
    ) || return $?

    # cleanup
    mv "${dir}/SHA512SUMS.NEW" "${dir}/SHA512SUMS"
    rm -f "${dir}/${fn}"
}

echo "Processing Debian stable gnome..."
dl_debian stable gnome
echo "Processing Debian testing gnome..."
dl_debian testing gnome

pm 09:55:18

YSITD bot

\\.iso\$" "${dir}/