#!/bin/bash

set -eu

if [ $# -ne 1 ]; then
    echo "usage: $(basename $0) PROXY-REVISION" >&2
    exit 64
fi
new_proxy_revision="$1"

bindir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
rootdir="$( cd $bindir/.. && pwd )"

old_proxy_version="$(tr -d '\n' <"$rootdir/.proxy-version")"
if [ -z "$old_proxy_version" ]; then
    echo "missing .proxy-version" >&2
    exit 1
fi

# Checkout the linkerd2-proxy repo to resolve the new proxy version to a SHA
# and obtain the commit log since the prior version.
tmp=$(mktemp -d -t l2-proxy.XXX)
git clone --depth=100 https://github.com/linkerd/linkerd2-proxy "$tmp"
cd "$tmp"

sha="$(git rev-parse --verify --quiet "${new_proxy_revision}")"
new_proxy_version="${sha:0:7}"

if ! git rev-parse --verify --quiet "${old_proxy_version}" ; then
    echo "The old proxy-version ${old_proxy_version} does not exist in the last 100 proxy commits." >&2
    exit 2
fi

echo "proxy: Update proxy to ${new_proxy_revision}" >"$tmp/commit.template"
echo "" >>"$tmp/commit.template"

git log --pretty=oneline --abbrev-commit --reverse "${old_proxy_version}..${new_proxy_version}" | \
    sed -E -e 's,^[a-f0-9]{7} ,* ,' \
    -e 's, \((#[0-9]+)\), (linkerd/linkerd2-proxy\1),' \
    >>"$tmp/commit.template"

cd "$rootdir"
echo "$new_proxy_version" >"$rootdir/.proxy-version"

git commit --file="$tmp/commit.template" --edit -- "$rootdir/.proxy-version"

rm -rf "$tmp"

git --no-pager show HEAD