Finds latest Spigot binary patch and applies to the specified file

spigot-patcher.sh

#!/bin/bash

## Validate arguments
if [ "$#" -ne 2 ]; then
	echo "Fetches latest Spigot patch and applies it."
	echo
	echo "Usage: <spigot-1649-jar-path> <output-file>"
	exit 1
fi

## Vars
SOURCE=$1
OUTPUT=$2

PATCHER="./SpigotPatcher-1.0.jar"
BASEURL="http://www.spigotmc.org/spigot-updates"

## Spigot patch function
function patch_spigot () {
	PATCHFILE=$1

	if [ -e $OUTPUT ]; then
		echo -n "Output file exists. Removing... "
		rm -f $OUTPUT
		echo "Done!"
	fi

	echo "Patching Spigot with $PATCHFILE..."
	echo

	java -jar $PATCHER $SOURCE $PATCHFILE $OUTPUT
	
	echo	
	echo "Patching complete!"
}

## Grab latest patch file from directory listing
echo -n "Locating latest Spigot patch... "
LASTPATCH=$(curl -L -s $BASEURL/ | egrep 'spigot-(.*)\.bps' | cut -d '>' -f 2 | cut -d '<' -f 1 | sort | tail -n 1)
ID=$(echo $LASTPATCH | sed 's,\.bps,,g')
URL="$BASEURL/$ID.bps"

## Fetch HTTP status code
STATUS=$(curl -L -s -I $URL | grep HTTP | cut -d ' ' -f 2)

## Check if file exists via HTTP 200
if [ $STATUS -eq 200 ]; then
	echo "Found: $ID"
	
	TIMESTAMP=$(date +%s)
	FILENAME="$ID-$TIMESTAMP.bps"

	echo -n "Fetching checksums... "
	SUMS=$(curl -L -s $BASEURL/$ID.md5)
	SUM_ORIG=$(echo "$SUMS" | grep -i original | awk '{print $2}')
	SUM_PATCH=$(echo "$SUMS" | grep -i patch | awk '{print $2}')
	SUM_FINAL=$(echo "$SUMS" | grep -i result | awk '{print $2}')
	echo "Done!"

	echo -n "Verifying source file... "
	TEMPSUM_ORIG=$(md5sum -b $SOURCE | awk '{print $1}')
	if [ $TEMPSUM_ORIG != $SUM_ORIG ]; then
		echo "Failed: $TEMPSUM_ORIG"
		echo "Please ensure that you've provided the correct source version of Spigot (#1649)."
		exit 3
	else
		echo "Success!"
	fi

	if [ -e $OUTPUT ]; then
		echo -n "Output file exists. Checking if patch is necessary... "
		TEMPSUM_FINAL=$(md5sum -b $OUTPUT | awk '{print $1}')
		
		if [ $TEMPSUM_FINAL == $SUM_FINAL ]; then
			echo "Patch not necessary!"
			exit
		else
			echo "Checksum does not match desired value."
		fi
	fi				

	echo -n "Downloading patch file... "
	curl -L -s -o ./$FILENAME $URL
	echo "Done!"

	echo -n "Verifying patch file... "
	TEMPSUM_PATCH=$(md5sum -b $FILENAME | awk '{print $1}')
	if [ $TEMPSUM_PATCH != $SUM_PATCH ]; then
		echo "Failed: got $TEMPSUM_PATCH instead of $SUM_PATCH"
		echo "Corrupt download? Try again later."
		exit 4
	else
		echo "Success!"
	fi

	patch_spigot $FILENAME
	rm -f ./$FILENAME

	echo -n "Verifying final jar... "
	TEMPSUM_FINAL=$(md5sum -b $OUTPUT | awk '{print $1}')
	if [ $TEMPSUM_FINAL != $SUM_FINAL ]; then
		echo "Failed: $TEMPSUM_FINAL"
		echo "Something is wrong with the patch or patcher. Are you up-to-date?"
		exit 5
	else
		echo "Success!"
	fi

	echo
	echo "All done! Patched and updated file here: $OUTPUT"	
	exit
fi

echo "Received invalid response from server while trying to locate latest patch. Please try again later."
echo "Code: $STATUS"
exit 2