#!/bin/bash
set -e #fail fast

#H Usage:
#H change_version.sh -h | change_version.sh --help
#H
#H prints this help and exits
#H
#H change_version.sh <-m modules...> [-i]
#H
#H   if a release version exists (extracted from TRAVIS_TAG)
#H   the maven versions of all modules will be changed to the given release version.
#H
#H module:
#H   directory of a maven project
#H i:
#H   increments version
#H
#H Environment variables:
#H   - TRAVIS_TAG
#H       if this is a tagged build then TRAVIS_TAG contains the version number.
#H       pattern: v[DIGIT].[DIGIT].[DIGIT]
# Arguments:
#   $1: exit code
function helpAndExit() {
  cat "$0" | grep "^#H" | cut -c4-
  exit "$1"
}

# takes a version (without leading v) and increments its
# last number by one.
# Arguments:
#   $1: version (without leading v) which will be patched
# Return:
#   version with last number incremented
function increment_version() {
  if [[ ! "$1" =~ [0-9]+\.[0-9]+\.[0-9]+ ]]; then
    echo "'$1' does not match tag pattern." >&2
    exit 1
  fi
  echo "${1%\.*}.$(expr ${1##*\.*\.} + 1)"
}

# changing version in pom and all its children
# Arguments:
#   $1: directory of pom
#   $2: new version
# Environment variable:
#   REL: relative path to this file
function change_version() {
  $REL/../mvnw -q versions:set -f "$1" -DnewVersion="$2" -DartifactId=* -DgroupId=* versions:commit
}

function main() {
  [[ $# -eq 0 || "$1" == '-h' || "$1" == '--help' ]] && helpAndExit 0
  REL=$(dirname "$0")
  while [[ $# -gt 0 ]]; do
    case $1 in
    -i)
      INCREMENT="true"
      shift # passed argument
      ;;
    -m | --modules)
      if [[ -z "$2" || "$2" == -* ]]; then
        echo "missing parameter for argument '-m|--modules'" >&2
        exit 1
      fi
      MODULES=($2)
      shift # passed argument
      shift # passed value
      ;;
    *) # unknown option
      echo "unknown parameter $1" >&2
      exit 1
      ;;
    esac
  done

  if [[ ${#MODULES[@]} -eq 0 ]]; then
    echo "Can not perform deployment without any modules" >&2
    helpAndExit 1
  fi

  if [[ "$TRAVIS_TAG" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
    version=$([[ -n "$INCREMENT" ]] && echo $(increment_version "${TRAVIS_TAG##v}")-SNAPSHOT || echo "${TRAVIS_TAG##v}")
    for dir in ${MODULES[@]}; do
      change_version "$dir" "$version"
    done
  else
    echo "skipped version change because this is not a release build"
  fi
}

main "$@"