version_script.sh

#!/bin/sh
# This script generates a version number based on the current Git commit and optionally tags the current commit.
#
# Prerequisites:
#   - A valid Git repository otherwise it will be generating with Default hash
#
# Usage:
#   - `./version_script.sh`: Generates a version number and prints it to the console.
#   - `./version_script.sh -t true`: Generates a version number and tags the current commit with that version.
#   - `./version_script.sh -h`: Displays help information.
DEFAULT_VERSION="00000.0"
LAST_COMMIT_TSP=""

VERSION=$DEFAULT_VERSION
CURRENT_BRANCH=''
IS_TAGGING_NEED_TO_PERFORMED=false
VERBOSE=false
LAST_COMMIT_HASH=''


help()  {
   echo "Usage: $0 "
   echo -e "\t tag| t if we want to tag current branch head"
    echo -e "\t help| h if we want to get uses"
    exit 1
}

get_last_git_commits_timestamp() {
   LAST_COMMIT_TSP=$(git log -1 --format="%ai" 2>/dev/null || echo 'NOT_FOUND')
}

identify_branch_name() {
   CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo 'NOT_FOUND')
}

get_last_git_commits_hash() {
  LAST_COMMIT_HASH=$( git rev-parse --short HEAD 2>/dev/null || echo '')
}

generate_new_version() {
   version=$(date +"%Y%m%dT%H%M%S" $LAST_TIME_STAMP)
   if [ "$CURRENT_BRANCH" == "main" ] || [ "$CURRENT_BRANCH" == "master" ]
   then
      # echo "Performing things for master branch"
      VERSION=$version"."$LAST_COMMIT_HASH
   else 
      # echo "Performing things for feature branch"
      VERSION=$version"."$LAST_COMMIT_HASH"-"$CURRENT_BRANCH
   fi
}


process_tagging_with_the_version() {
   echo "Starting tagging process, performing tag on branch: $CURRENT_BRANCH"
   eval "$(git tag $VERSION)"
   echo "Pushing a new tag to remote $VERSION"
   eval "$(git push -u origin $VERSION)"

}

main() {
  startTime=$( date +"%Y-%m-%dT%H:%M:%S")
   echo "Process to generate a new version is started : $startTime"
   
   # Checking the branch status 
   identify_branch_name
   if [ "$CURRENT_BRANCH" == "" ] || [ "$CURRENT_BRANCH" == "NOT_FOUND" ]
   then
      echo "ERROR::Unable to find branch, hence failing the process with error!!!!"
      exit 1
   fi   
   # echo "Branch is: $CURRENT_BRANCH"
   # Identifying the last commit timestamp to derive the version
   get_last_git_commits_timestamp

   get_last_git_commits_hash
   
   generate_new_version

   echo "Generated git version: $VERSION with tagging requirement : $IS_TAGGING_NEED_TO_PERFORMED"

   if [ "$IS_TAGGING_NEED_TO_PERFORMED" == true ] 
   then
      process_tagging_with_the_version "$VERSION"
   fi

   endTime=$(date +"%Y-%m-%dT%H:%M:%S")
   echo "Process to generate a new version is completed: $endTime"
}

#Parsing the supplied arguments
while [[ "$#" -gt 0 ]]; do
      case $1 in
          -t|--tag) IS_TAGGING_NEED_TO_PERFORMED="$2"; shift ;;
          -h|--help) help ;;
          *) echo "Unknown parameter passed: $1"; exit 1 ;;
      esac
    shift
    done

#Performing main method to perform version generation operation
main