#!/bin/bash

set -o errexit
set -o nounset

if [[ $# -ne 1 ]]; then
    echo "usage: ${0##*/} (edge|stable)-xx.xx.xx" >&2
    exit 1
fi

new_linkerd_version="$1"

# Verify the tag format
tag_format="^(edge|stable)-([0-9]+)\.([0-9]+)\.([0-9]+)$"
if [[ $new_linkerd_version =~ $tag_format ]]; then
    # todo: Use these values to verify the tag version increment.
    # release_channel="${BASH_REMATCH[1]}"
    # release_major="${BASH_REMATCH[2]}"
    # release_minor="${BASH_REMATCH[3]}"
    # release_patch="${BASH_REMATCH[4]}"
    :
else
    echo "tag format incorrect; expected: $tag_format"
    echo "example: edge-20.12.2, stable-2.10.1"
    exit 1
fi

# todo: Verify the tag version increment.

rootdir=$( cd "${0%/*}"/.. && pwd )

# Make temporary file to save the release commit message into.
tmp=$(mktemp -t release-commit-message.XXX.txt)

# Save commit message into temporary file.
#
# Match each occurence of the regex and increment `n` by 1. While n == 1
# (which is true only for the first section) print that line of `CHANGES.md`.
# This ends up being the first section of release changes.
awk '/^## (edge|stable)-[0-9]+\.[0-9]+\.[0-9]+/{n++} n==1' "$rootdir"/CHANGES.md > "$tmp"

# Create an unsigned tag with the commit message.
git tag -s -F "$tmp" "$new_linkerd_version"