fetch-configlet

#!/usr/bin/env bash

# This file is a copy of the
# https://github.com/exercism/configlet/blob/main/scripts/fetch-configlet file.
# Please submit bugfixes/improvements to the above file to ensure that all tracks benefit from the changes.

set -eo pipefail

curlopts=(
  --silent
  --show-error
  --fail
  --location
  --retry 3
)

if [[ -n "${GITHUB_TOKEN}" ]]; then
  curlopts+=(--header "authorization: Bearer ${GITHUB_TOKEN}")
fi

get_download_url() {
  local os="$1"
  local ext="$2"
  local latest='https://api.github.com/repos/exercism/configlet/releases/latest'
  local arch
  case "$(uname -m)" in
    aarch64|arm64) arch='arm64'  ;;
    x86_64)        arch='x86-64' ;;
    *686*)         arch='i386'   ;;
    *386*)         arch='i386'   ;;
    *)             arch='x86-64' ;;
  esac
  local suffix="${os}_${arch}.${ext}"
  curl "${curlopts[@]}" --header 'Accept: application/vnd.github.v3+json' "${latest}" |
    grep "\"browser_download_url\": \".*/download/.*/configlet.*${suffix}\"$" |
    cut -d'"' -f4
}

main() {
  local output_dir
  if [[ -d ./bin ]]; then
    output_dir="./bin"
  elif [[ $PWD == */bin ]]; then
    output_dir="$PWD"
  else
    echo "Error: no ./bin directory found. This script should be ran from a repo root." >&2
    return 1
  fi

  local os
  case "$(uname -s)" in
    Darwin*)   os='macos'   ;;
    Linux*)    os='linux'   ;;
    Windows*)  os='windows' ;;
    MINGW*)    os='windows' ;;
    MSYS_NT-*) os='windows' ;;
    *)         os='linux'   ;;
  esac

  local ext
  case "${os}" in
    windows) ext='zip'    ;;
    *)       ext='tar.gz' ;;
  esac

  echo "Fetching configlet..." >&2
  local download_url
  download_url="$(get_download_url "${os}" "${ext}")"
  local output_path="${output_dir}/latest-configlet.${ext}"
  curl "${curlopts[@]}" --output "${output_path}" "${download_url}"

  case "${ext}" in
    zip) unzip "${output_path}" -d "${output_dir}"   ;;
    *)   tar xzf "${output_path}" -C "${output_dir}" ;;
  esac

  rm -f "${output_path}"

  local executable_ext
  case "${os}" in
    windows) executable_ext='.exe' ;;
    *)       executable_ext=''     ;;
  esac

  local configlet_path="${output_dir}/configlet${executable_ext}"
  local configlet_version
  configlet_version="$(${configlet_path} --version)"
  echo "Downloaded configlet ${configlet_version} to ${configlet_path}"
}

main