#!/usr/bin/env bash
## Last Updated: 2022-04-25
#
## Info: Download all pre-built iso from Debian
## (via wget)
#
## Source: https://gitlab.com/-/snippets/2132933
#

## Quit on error
#set -e

## Quit if any command in the chain errors
#set -o pipefail

## Variable has to be defined
set -u

# -----------------------------------------------------------------------------

## get_deb_ver [archive|release]
function get_deb_ver() {
  curl -s http://cdimage.debian.org/cdimage/$1/ \
    | awk -F '"' '/href/ {print $6}' \
    | grep -v '-' \
    | grep -v '_' \
    | grep -v '?' \
    | grep -v 'live/' \
    | grep -v 'current/' \
    | grep -v 'project' \
    | grep '/$' \
    | grep -v '^/' \
    | sed 's_/__g' \
    | sort -u \
    | sort -t. -k 1,1n -k 2,2n -k 3,3n
}


function print_status() {
  printf '%-13s:' "${ver}/${arch}"
}


## download_iso [archive|release] $ver $arch
function download_iso(){
  major=$( printf "%02d" "$( echo ${ver} | cut -d '.' -f1 )" )

  status=$(
    curl \
      --silent \
      --fail \
      --location \
      "http://cdimage.debian.org/cdimage/$1/${ver}/${arch}/iso-cd/"
  )

  [ $? != "0" ] \
    && echo "[-] $( print_status ) Not getting HTTP 200 ~ http://cdimage.debian.org/cdimage/$1/${ver}/${arch}/iso-cd/" >&2 \
    && return

  iso=$(
    curl --silent "http://cdimage.debian.org/cdimage/$1/${ver}/${arch}/iso-cd/" \
      | awk -F '"' '/href/ {print $6}' \
      | grep 'debian-[0-9]' \
      | grep -v businesscard
  )

  if [ "$( echo "${iso}" | wc -l )" -gt 1 ]; then
    iso=$(
      echo "${iso}" \
        | grep CD-1.iso \
        | head -n 1
    )
  fi

  [ -z "${iso}" ] \
    && echo "[-] $( print_status ) Missing pre-built iso-cd (will need to use jigdo) ~ http://cdimage.debian.org/cdimage/$1/${ver}/${arch}/iso-cd/" >&2 \
    && return

  new_iso=$( echo "${iso}" | sed 's_debian-[0-9]*-'${arch}'_debian-'${ver}'-'${arch}'_' )
  echo -n "[i] $( print_status ) Downloading ${iso}"
  if [ "${iso}" != "$new_iso" ]; then
    echo " -> ${new_iso}"
  else
    echo ""
  fi

  mkdir -p "Debian-${major}/"
  wget \
      --continue \
      --no-verbose \
      -O "Debian-${major}/${new_iso}" \
      "http://cdimage.debian.org/cdimage/$1/${ver}/${arch}/iso-cd/${iso}" \
    || echo -e "[-] Issue with wget\n" >&2
}

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

## Check if root (due to NAS)
if [ "$(id -u)" -eq 0 ]; then
  echo "[-] You are root. Please switch to non-root" >&2
  exit 1
fi

## Move to script folder
cd "$( dirname $BASH_SOURCE )/"
script_path="$( readlink -f "$( readlink "${BASH_SOURCE[0]}" )" || true)"
cd "$( dirname "${script_path}" )/"
pwd


## Timestamp
date -u > last.txt
chmod 0644 last.txt

## Fresh start, delete any incorrect files
find . \
    -type f \
    -name '[a-z]*.iso' \
    -empty \
    -print \
    -delete \
    2>/dev/null \
  || true

echo -e "\n[i] Doing archived images ~ http://cdimage.debian.org/cdimage/archive/"
for ver in $( get_deb_ver archive ); do
  for arch in amd64 i386; do
    download_iso archive
  done
done

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

echo -e "\n[i] Doing current release images ~ http://cdimage.debian.org/cdimage/release/"
for ver in $( get_deb_ver release ); do
  for arch in amd64 i386; do
    download_iso release
  done
done
echo ""

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

## Generate hashes
rm -f {MD5,SHA1,SHA256}SUM
echo "[i] Generating hashes"
find . \
    -type f \
    -name '*.iso' \
  2>/dev/null \
  | sort -h \
  | while read -r x; do
    echo "${x}"
    md5sum "${x}" >> MD5SUM;
    sha1sum "${x}" >> SHA1SUM;
    sha256sum "${x}" >> SHA256SUM;
done
echo ""

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

## Timestamp
date -u >> last.txt

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

## Done
echo "[i] Done"
exit