autotag

#!/usr/bin/env bash
# AutoTag application.
#
# MIT License
#
# Copyright (c) 2020 - 2021 MichaelCurrin
#
# updated by f@pulilab.com on 06.12.2021
#
# https://github.com/MichaelCurrin/auto-tag/blob/master/LICENSE
set -e

FALLBACK_TAG='0.0.0'
USAGE='USAGE:
    autotag LEVEL [-p] [-u] [-h]
'
HELP="HELP:
    Increment git tag using given increment level.

    Positional arguments:
        LEVEL        : 'M' for major, 'm' for minor or 'b' for bug.

    Flags:
        -h --help    : Show help and exit.
        -p --preview : Do a dry run to show the new tag label only, without creating it.
                       This must be used as the 2nd arg i.e. after the LEVEL.
        -u --upgrade : Download latest script from GitHub, write over current script to
                       install it, then exit. Uses cURL and not Git. If using this flag,
                       not other options are needed or used.
"
USER_ARGS="$*"
DOWNLOAD_URL='https://raw.githubusercontent.com/MichaelCurrin/auto-tag/master/autotag'

# Dynamic variables. Unfortunately all are global but at least there are functions now so the script
# is easier to work with. Also they don't have to be set here even, but are set for clarity.
LEVEL_CHOICE=''
PREVIEW=''
MAJOR=''
MINOR=''
BUG=''
LAST_TAG=''
NEW_TAG=''

help_if_needed() {
  if [[ "$#" -eq 0 ]] || [[ "$1" == '-h' ]] || [[ "$1" == '--help' ]]; then
    echo "$USAGE"
    echo "$HELP"
    exit 1
  fi
}

invalid_args_error() {
  echo "🛑 Invalid arguments: '$USER_ARGS'"
  echo
  echo "$USAGE"
  exit 1
}

download_update_if_needed() {
  if [[ "$#" -eq 0 ]] || [[ "$1" == '-u' ]] || [[ "$1" == '--upgrade' ]]; then
    SCRIPT_FILEPATH="$(realpath $0)"

    echo 'ℹ️ Current path: $SCRIPT_FILEPATH'

    echo '⬇️ Downloading latest script using curl'
    curl -q "$DOWNLOAD_URL" >"$SCRIPT_FILEPATH"
    echo '🚀 `autotag` script updated. Exiting.'
    exit 0
  fi
}

process_args() {
  LEVEL_CHOICE="$1"

  if [[ "$2" ]]; then
    if [[ "$2" == '-p' ]] || [[ "$2" == '--preview' ]]; then
      PREVIEW='true'
    else
      invalid_args_error
    fi
  else
    PREVIEW='false'
  fi
}

get_last_tag() {
  LAST_TAG=$(git describe --abbrev=0 --tags 2>/dev/null)
  LAST_TAG="${LAST_TAG:-$FALLBACK_TAG}"
  LAST_TAG="${LAST_TAG/v/}"

  # Replace dot with space then split into array.
  LAST_TAG_ARR=(${LAST_TAG//./ })

  MAJOR="${LAST_TAG_ARR[0]}"
  MINOR="${LAST_TAG_ARR[1]}"
  BUG="${LAST_TAG_ARR[2]}"
}

set_level() {
  # Although the exit only happens after fetching, this needs to happen here so variables are set.
  # Otherwise a refactor is needed to check M|m|b and exit if needed, then actually calculate here.
  case "$LEVEL_CHOICE" in
  "M")
    ((MAJOR += 1))
    MINOR=0
    BUG=0
    ;;
  "m")
    ((MINOR += 1))
    BUG=0
    ;;
  "b")
    ((BUG += 1))
    ;;
  *)
    invalid_args_error
    ;;
  esac
}

make_tag() {
  git tag \
    -a "$NEW_TAG" \
    -m "$NEW_TAG"
}

run() {
  echo '🚛 Fetching tags...'
  git fetch --tags

  echo '🔍 Finding most recent tag...'
  get_last_tag
  echo "👴 Last tag: $MAJOR.$MINOR.$BUG"

  set_level
  NEW_TAG="$MAJOR.$MINOR.$BUG"
  echo "⭐ New tag: $NEW_TAG"

  # For some reason these emojis need a double space after to avoid looking squashed, at least on
  # macOS.
  if [[ "$PREVIEW" == true ]]; then
    echo '⏭️  Skipping tag creation'
  else
    echo '🏷️  Creating annotated tag...'
    make_tag
  fi
}

main() {
  help_if_needed $@
  download_update_if_needed $@
  process_args $@
  run
}

main $@