VERSION_PATH="VERSION"
DOCKERFILE_PATH="."
LATEST=false

print_usage() {
  echo -e "Usage: generateDockerImage.sh [options]

  options:
    -n, --name*             name of the docker image
    -f, --file              \e[3mpath/to/DOCKERFILE\e[0m (e.g. "./src")
    -m, --major             sets the major version number, will overwrite version specified in VERSION file, resets the build version to 0
    -i, --minor             sets the minor version number, will overwrite version specified in VERSION file, resets the build version to 0
    -v, --version           \e[3mpath/to/VERSION\e[0m file (e.g. "./src")
    -l, --latest            ignores all versioning and sets docker tag to latest
    -t, --tag               ignores all versioning and sets docker tag to value
    -h, --help              prints this information
  
  * = required"
  exit 0
}

while test $# -gt 0; do
  case "$1" in
    -n|--name) 
      shift
      if test $# -gt 0 
      then
        export NAME=$1
      fi
      shift
      ;;
    -m|--major) 
      shift
      if test $# -gt 0; 
      then
        export MAJOR=$1
      fi
      shift
      ;;
    -i|--minor)
      shift
      if test $# -gt 0; 
      then
        export MINOR=$1
      fi
      shift
      ;;
    -f|--file)
      shift
      if test $# -gt 0; 
      then
        DOCKERFILE_PATH=$1
      fi
      shift
      ;;
    -v|--version)
      shift
      if test $# -gt 0; 
      then
        VERSION_PATH=$1"/VERSION"
      fi
      shift
      ;;
    -l|--latest)
      shift
      LATEST=true
      shift
      ;;
    -t|--tag)
      shift
      if test $# -gt 0; 
      then
        export TAG=$1
      fi
      shift
      ;;
    -h|--help) print_usage ;;
    *) print_usage
       break
       ;;
  esac
done

if [[ -z $NAME ]]
then
  echo -e "missing image name; use -n \e[3mname\e[0m"
  exit 1
fi

if $LATEST
then
    echo "build -t ${NAME}:"latest" $DOCKERFILE_PATH"
    docker build -t ${NAME}:"latest" $DOCKERFILE_PATH
    exit 0
fi

if ! [[ -z $TAG ]]
then
  echo "docker build -t "${NAME}:${TAG}" $DOCKERFILE_PATH"
  docker build -t ${NAME}:${TAG} $DOCKERFILE_PATH
  exit 0
fi

if [ -f ${VERSION_PATH} ];
then
    VERSION=$(<${VERSION_PATH})
    IFS='.' read -ra NEWVERSION <<< "$VERSION"
    NEWVERSION[2]=$(($((${NEWVERSION[2]}))+1))
    if [[ -z "$MAJOR" ]]
    then
        if [[ -z "$MINOR" ]]
        then
            echo "${NEWVERSION[0]}.${NEWVERSION[1]}.${NEWVERSION[2]}">$VERSION_PATH
        else
            echo "${NEWVERSION[0]}.${MINOR}.0">$VERSION_PATH
        fi
    else
        if [[ -z "$MINOR" ]]
        then
            echo "${MAJOR}.${NEWVERSION[1]}.0">$VERSION_PATH
        else
            echo "${MAJOR}.${MINOR}.0">$VERSION_PATH
        fi
        
    fi
else
    if [[ -z "$MAJOR" ]]
    then
        if [[ -z "$MINOR" ]]
        then
            echo "0.0.0">$VERSION_PATH
        else
            echo "0.${MINOR}.0">$VERSION_PATH
        fi
    else
        if [[ -z "$MINOR" ]]
        then
            echo "${MAJOR}.0.0">$VERSION_PATH
        else
            echo "${MAJOR}.${MINOR}.0">$VERSION_PATH
        fi
        
    fi
fi

VERSION=$(<${VERSION_PATH})
echo "docker build -t ${NAME}:${VERSION} $DOCKERFILE_PATH"
docker build -t ${NAME}:${VERSION} $DOCKERFILE_PATH