#!/bin/bash
#
# Simple Debian image downloader.
#

# Parameters
HASHES="MD5SUMS SHA1SUMS SHA256SUMS SHA512SUMS"

# Arguments
BASENAME="`basename $0`"
URL="$1"
BASE="`dirname $URL`"
RATE="$2"
FILENAME="`basename $URL`"

# Syntax
if [ -z "$1" ]; then
  echo "usage: $BASENAME <image-url>"
  exit 1
fi

# Fetch hashes
for hash in $HASHES; do
  wget -c $BASE/$hash
  wget -c $BASE/$hash.sig
done

# Set rate limit
if [ ! -z "$RATE" ]; then
  LIMIT="--limit-rate=$RATE"
fi

# Get the image
wget -c $LIMIT $URL

# Check hashes
for hash in $HASHES; do
  echo "Checking $FILENAME against $hash file..."
  check="`echo $hash | tr '[:upper:]' '[:lower:]' | sed -e 's/s$//'`"
  grep -e "$FILENAME$" $hash | $check -c
done

# Check hash integrity
for hash in $HASHES; do
  echo "Checking $hash.sig..."
  gpg --verify $hash.sig
done