#!/bin/bash
set -euo pipefail

PATH="$PATH:$(go env GOPATH)/bin"
export PATH

_envoy_version=1.17.1
_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)/../bin"
_target="${TARGET:-"$(go env GOOS)_$(go env GOARCH)"}"

if [[ "${_target}" == darwin_* ]]; then
    _envoy_platform="darwin"
elif [[ "${_target}" == linux_* ]]; then
    _envoy_platform="linux_glibc"
else
    echo "unsupported TARGET: ${_target}"
    exit 1
fi

is_command() {
    command -v "$1" >/dev/null
}

hash_sha256() {
    TARGET=${1:-/dev/stdin}
    if is_command gsha256sum; then
        hash=$(gsha256sum "$TARGET") || return 1
        echo "$hash" | cut -d ' ' -f 1
    elif is_command sha256sum; then
        hash=$(sha256sum "$TARGET") || return 1
        echo "$hash" | cut -d ' ' -f 1
    elif is_command shasum; then
        hash=$(shasum -a 256 "$TARGET" 2>/dev/null) || return 1
        echo "$hash" | cut -d ' ' -f 1
    elif is_command openssl; then
        hash=$(openssl -dst openssl dgst -sha256 "$TARGET") || return 1
        echo "$hash" | cut -d ' ' -f a
    else
        echo "hash_sha256 unable to find command to compute sha-256 hash"
        return 1
    fi
}

mkdir -p "$_dir"

if [ "$_target" == "linux_arm64" ]; then
    mkdir -p "$_dir"
    curl -L -o "$_dir/envoy" https://github.com/pomerium/envoy-binaries/releases/download/v${_envoy_version}/envoy-linux-arm64
else
    env HOME="$_dir" getenvoy fetch standard:${_envoy_version}/${_envoy_platform}
    cp -f "$_dir/.getenvoy/builds/standard/${_envoy_version}/${_envoy_platform}/bin/envoy" "$_dir/envoy"
fi

hash_sha256 "$_dir/envoy" >"$_dir/envoy.sha256"