#!/usr/bin/env bash

set -eu

os() {
  os=$(uname -s)
  arch=""
  case $os in
    CYGWIN* | MINGW64*)
      os=windows
      ;;
    Darwin)
      os=darwin
      ;;
    Linux)
      os=linux
      arch=$(uname -m)
      case $arch in
        x86_64)
          arch=amd64
          ;;
        armv8*)
          arch=arm64
          ;;
        aarch64*)
          arch=arm64
          ;;
        armv*)
          arch=arm
          ;;
        amd64|arm64)
          arch=$arch
          ;;
        *)
          echo "unsupported architecture: $arch" >&2
          exit 1
          ;;
      esac
      ;;
    *)
      echo "unsupported os: $os" >&2
      exit 1
      ;;
  esac

  if [ -n "$arch" ]; then
    echo "$os-$arch"
  else
    echo "$os"
  fi
}