#!/usr/bin/env bash
# Description:  Git hook to check the JIRA reference in the commit message
# Usage:        Copy this file on your hooksPath with the name "commit-msg"
# Ref:          https://aviatrix.atlassian.net/l/c/ARC3NMy1#Git-client-hook-for-automatic-Jira-ref-insertion

set -e

[ -z "${GITHOOK_DEBUG}" ] || set -x

# hook arguments
COMMIT_MSG_FILE=$1
# Possible values are none (git commit), message (git commit -m <msg>), template, merge, squash, or commit
COMMIT_SOURCE=$2

BRANCH=$(git branch --show-current)

function get_sed () {
  OS=$(uname  -s)
  if [ "${OS}" == "Linux" ]; then
    SED=$(command -v sed)
  else
    SED=$(command -v gsed)
  fi
  if [ -z "${SED}" ]; then
    echo ">> GNU 'sed' was not found on the system."
    echo ">> Please install it"
    exit 1
  fi
  echo "${SED}"
}

function not_include_ticket () {
  set -o pipefail
  if $(cat "$*" | grep -q "^JIRA: "); then
    return 1
  fi
  return 0
}

# Function to extract the ticket number:
# Ex: AVXSRE-12324-toto -> AVXSRE-1234
#     AVXSRE-12134/titi -> AVXSRE-1234
function get_branch_name () {
  echo "$*" | ${SED} -e 's@\([[:alpha:]]\+\).*-\([[:digit:]]\+\).*@\1-\2@g'
}

SED="$(get_sed)"
BRANCH="$(get_branch_name $(git branch --show-current))"

# check branch name isn’t empty (typical e.g. during rebase)
if not_include_ticket "${COMMIT_MSG_FILE}" && [ -n "${BRANCH}" ]; then
  # check that this is a "message": if a -m or -F option was given
  if [ "${COMMIT_SOURCE}" == "message" ]; then
    echo >> ${COMMIT_MSG_FILE}
    echo "JIRA: ${BRANCH}" >> ${COMMIT_MSG_FILE}
    exit 0
  fi

  # check that this is a "commit"
  if [ -z "${COMMIT_SOURCE}" ]; then
    ${SED} -i "1s@^@\n\nJIRA: ${BRANCH}@" ${COMMIT_MSG_FILE}
    exit 0
  fi

  # check that this is an "amend"
  if [ "${COMMIT_SOURCE}" == "commit" ]; then
    ${SED} -i "2s@^@\n\nJIRA: ${BRANCH}\n@" ${COMMIT_MSG_FILE}
    exit 0
  fi
fi