#!/bin/bash -eu
versions() {
	git tag | grep '^v' | sort --field-separator=. --key=1,1nr --key=2,2nr --key=3,3nr
}

if [[ $# > 0 ]]; then
	current="$1"
else
	current="$(versions | head -n1)"
fi
if [[ $# > 1 ]]; then
	previous="$2"
else
	previous="$(versions | head -n2 | tail -n1)"
fi

datestamp="$(date '+%Y-%m-%d')"

title="${datestamp} | $previous -> $current"
echo "${title}"

underline="$(head -c ${#title} /dev/zero | tr '\0' '=')"
echo "${underline}"

git log "${previous}..${current}" --pretty=oneline | cut -d' ' -f2- | sed -E -e 's/^/* /'