#!/bin/bash
#
# patchjar - for quick patching jar files in a world of maven projects
#
# Usage: patchjar <jar-file> <destination> <dir> [<dir2> <dir3> ...]
#
# jar-file:      path to a jar file. you can use relative paths
# destination:   a local path or user@host:path
# dirs:          any directory with a maven pom.xml file
#
# Rationale: building uber-jars is time-consuming. Uber-jars are wonderful for
# deployment, but can sometimes feel like the slow down iteration cycles.
#
# patchjar runs "mvn compile" in each maven directory, then directly updates
# the jar via "jar uvf". Only the class files that changed are updated.
#
# Once all patches are applied, patchjar copies the jar file to the destination.
#

function die () {
  echo >&2 "${1}"
  exit 1
}

START_DIR=$(pwd)
JAR="$(cd $(dirname ${1}) && pwd)/$(basename ${1})"
DESTINATION="${2}"
shift 2

MAVEN="mvn -DskipTests=true -Dcheckstyle.skip=true"

for dir in ${@} ; do
  cd ${START_DIR} && cd $(cd ${dir} && pwd) \
  && ${MAVEN} compile \
  && cd target/classes \
  && classes="$(find . -type f -mmin -3)" && if [ -z "${classes}" ] ; then classes="./*" ; fi \
  && jar uvf ${JAR} ${classes} \
  || die "Error building: ${dir}"
done

cd ${START_DIR}
scp ${JAR} ${DESTINATION}