#!/bin/bash

# To update or install in a new repository, run the following command
# N=.git/hooks/prepare-commit-msg ; curl -L https://goo.gl/5Mmuoi -o $N --create-dirs; chmod 744 $N

# Assuming all branches are created as `WWW-nnn-Human-readable-suffixes`
# this commit-msg hook will prepend all commit messages with the ticket
# name/number, for example:
# Branch: ADV-007-License-to-kill
# Message: Bad guy has been identified.
# Prepends: ADV-007:
# Result: ADV-007: Bad guy has been identified.

# This way you can customize which branches should be skipped when
# prepending commit message. (Untested after implementing trimming)
if [ -z "$BRANCHES_TO_SKIP" ]; then
  BRANCHES_TO_SKIP=(master develop test)
fi

# Get the full branch name
BRANCH_NAME=$(git symbolic-ref --short HEAD)
# Chop of sub-dirs (like `feature/`)
BRANCH_NAME="${BRANCH_NAME##*/}"
# Keep only ticket-number, ditch the human readable part i.e. `ADV-000`
BRANCH_NAME=$(echo $BRANCH_NAME | sed -e 's:^\([^-]*-[^-]*\)-.*:\1:' -e \
    'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/')

BRANCH_EXCLUDED=$(printf "%s\n" "${BRANCHES_TO_SKIP[@]}" | grep -c "^$BRANCH_NAME$")
BRANCH_IN_COMMIT=$(grep -c "\[$BRANCH_NAME\]" $1)

if [ -n "$BRANCH_NAME" ] && ! [[ $BRANCH_EXCLUDED -eq 1 ]] && ! [[ $BRANCH_IN_COMMIT -ge 1 ]]; then
  sed -i.bak -e "1s/^/$BRANCH_NAME: /" $1
fi