#!/usr/bin/env sh

# If the first argument to this script is "latest" or unset, it fetches the
# latest proxy binary from the linkerd2-proxy github releases. If it's set to
# a linkerd2-proxy version number (such as v2.76.0), it will fetch the binary
# matching that version number instead.

set -eu

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

version=${1:-latest}
if [ "$version" = latest ]; then
  version=$(curl -sL https://api.github.com/repos/linkerd/linkerd2-proxy/releases/latest |jq -r .tag_name | sed 's,^release/,,')
fi

assetbase="https://github.com/linkerd/linkerd2-proxy/releases/download/release%2F${version}"
arch=${2:-amd64}
pkgname="linkerd2-proxy-${version}-${arch}"
pkgfile="${pkgname}.tar.gz"
shafile="${pkgname}.txt"

mkdir -p "$builddir"
cd "$builddir"
curl -sLO "$assetbase/$pkgfile"
curl -sLO "$assetbase/$shafile"

tar -zxvf "$pkgfile" >&2
expected=$(awk '{print $1}' "$shafile")
if [ "$(uname)" = "Darwin" ]; then
  computed=$(openssl dgst -sha256 "$pkgfile" | awk '{print $2}')
else
  computed=$(sha256sum "$pkgfile" | awk '{print $1}')
fi
if [ "$computed" != "$expected" ]; then
  echo 'sha mismatch' >&2
  exit 1
fi

mv "$pkgname/LICENSE" .
mv "$pkgname/bin/linkerd2-proxy" .
rm -r "$pkgfile" "$pkgname"
mv linkerd2-proxy "$pkgname"
echo "$builddir/$pkgname"