#!/bin/sh

# Copyright 2012 Paul Wise
# Released under the MIT/Expat license, see doc/COPYING

# Downloads the URLs to files in a safe and useful way, fixes CRLF EOL
#
# Usage:
# get-url-eol-fix <URL to download> <where to save the file>

# Get a temporary filename
tmp="$(mktemp "$(readlink --canonicalize-missing "$2").tmp.XXXXXXXXXXXXXX")" || exit $?

# Try to download a newer file
out="$(curl --config "$CURLRC" --time-cond "$2.remote-timestamp" --output "$tmp" "$1" 2>&1)"

# Preserve the exit value from curl
ret=$?

# We want to stop on errors from here on
set -e

# Remove any CR characters
tr --delete '\r' < "$tmp" > "$tmp-lf"

# Preserve the modification timestamp
touch --reference "$tmp" "$tmp-lf"

# Move the converted file over
mv --force "$tmp-lf" "$tmp"

# If curl failed then complain
if [ $ret -ne 0 ]; then
	echo "Error $ret downloading $1:"
	echo "$out"
# If the new file isn't empty or exactly the same then rename it
elif [ -s "$tmp" ] && ! cmp --quiet "$tmp" "$2" ; then
	# Save the remote modification date separately
	touch --reference "$tmp" "$2.remote-timestamp"
	# Fix the permissions
	chmod --reference "$2.remote-timestamp" "$tmp"
	# Move the new file over
	mv --force "$tmp" "$2"
	# Use a local timestamp for the file
	touch "$2"
fi

# Clean up afterwards
rm --force "$tmp"

exit $ret