#! /bin/bash -eu

# This is a Mercurial hook script which sits in your team's master repository, and tags every time someone pushes a new head.
# The idea is that you can distinguish changesets which were just local working commits from ones which were released to the team.
# Note that if you want to know who did a push, it's the user in whose name the tag was made

# [hooks]
# changegroup.tag = /path/to/tag-changegroup.sh name-for-this-repo
# don't keep the script as a versioned file in the repository, as it will all go horribly wrong when it updates around branches
# when a hook runs, pwd is the root of the repo; you could consider storing the tag script inside the .hg directory

REPO_NAME=$1

# TODO: support different strategies for update before tagging:
# 1. don't; put the tag wherever
# 2. update to the changeset being tagged, as now
# 3. switch to a configured branch or bookmark, so that tags are always in some out-of-the-way place where users don't need to pull immediately

HG_REV=$(hg identify -r $HG_NODE -n)

hg heads --template '{rev} {node} {branch}\n' | while read HEAD_REV HEAD_NODE HEAD_BRANCH
do
	if [[ $HEAD_REV -ge $HG_REV ]]
	then
		# question: does the tag use the HG_NODE or HEAD_NODE? is it based on the identity of the changegroup or the changeset?
		TAG=$REPO_NAME.$HEAD_BRANCH.$HG_REV
		echo "Tagging revision $HEAD_REV:$HEAD_NODE as $TAG"
		hg update -cq -r $HEAD_REV
		hg tag -q -r $HEAD_REV $TAG
	fi
done

echo "DON'T FORGET TO PULL AND MERGE!"