#!/usr/bin/env bash

set -o nounset -o pipefail -o errexit

NODEJS_CHECK_SIGNATURES="${NODEJS_CHECK_SIGNATURES:-strict}"

install_nodejs() {
  local install_type=$1
  local version=$2
  local install_path=$3

  local tmp_download_dir="$(mktemp --directory -t 'asdf_nodejs_XXXXXX')"

  ## Do this first as it is fast but could fail.
  download_and_verify_checksums "$install_type" "$version" "$tmp_download_dir"

  local archive_path="${tmp_download_dir}/$(get_archive_file_name "$install_type" "$version")"
  download_file "$(get_download_url "$install_type" "$version")" "${archive_path}"

  verify_archive "$tmp_download_dir"

  # running this in a subshell
  # we don't want to disturb current working dir
  (
    if [ "$install_type" != "version" ]; then
      tar zxf "$archive_path" -C "$install_path" --strip-components=1 || exit 1
      cd "$install_path" || exit 1

      local configure_options="$(construct_configure_options "$install_path")"

      # shellcheck disable=SC2086
      ./configure $configure_options || exit 1
      make
      make install

      if [ $? -ne 0 ]; then
        rm -rf "$install_path"
        exit 1
      fi
    else
      tar zxf "$archive_path" -C "$install_path" --strip-components=1 || exit 1
    fi

    mkdir -p "$install_path/.npm/lib/node_modules/.hooks"
    cp "$(dirname "$(dirname "$0")")"/npm-hooks/* "$install_path/.npm/lib/node_modules/.hooks/"
    chmod +x "$install_path"/.npm/lib/node_modules/.hooks/*
  )
}


construct_configure_options() {
  local install_path=$1

  if [ -z "${NODEJS_CONFIGURE_OPTIONS:-}" ]; then
    local configure_options="--dest-cpu=$(get_nodejs_machine_hardware_name)"

    if [ "${NODEJS_EXTRA_CONFIGURE_OPTIONS:-}" != "" ]; then
      configure_options="$configure_options ${NODEJS_EXTRA_CONFIGURE_OPTIONS:-}"
    fi
  else
    local configure_options="${NODEJS_CONFIGURE_OPTIONS:-}"
  fi

  configure_options="$configure_options --prefix=$install_path"

  echo "$configure_options"
}


get_nodejs_machine_hardware_name() {
  local machine_hardware_name=$(uname --machine)

  case "$machine_hardware_name" in
    'x86_64') local cpu_type="x64";;
    'i686') local cpu_type="x86";;
    *) local cpu_type="$machine_hardware_name";;
  esac

  echo "$cpu_type"
}


download_file() {
  local download_url="$1"
  local download_path="$2"

  curl -Lo "$download_path" -C - "$download_url"
}


get_archive_file_name() {
  local install_type="$1"
  local version="$2"

  if [ "$install_type" = "version" ]; then
    local pkg_name="node-v${version}-$(uname --kernel-name | tr '[:upper:]' '[:lower:]')-$(get_nodejs_machine_hardware_name)"
  else
    local pkg_name="${version}"
  fi

  echo "${pkg_name}.tar.gz"
}


get_download_url() {
  local install_type="$1"
  local version="$2"

  if [ "$install_type" = "version" ]; then
    local download_url_base="https://nodejs.org/dist/v${version}"
  else
    local download_url_base="https://github.com/nodejs/node/archive"
  fi

  echo "${download_url_base}/$(get_archive_file_name "$install_type" "$version")"
}


get_signed_checksum_download_url() {
  local install_type=$1
  local version=$2

  if [ "$install_type" = "version" ]; then
    echo "https://nodejs.org/dist/v${version}/SHASUMS256.txt.asc"
  else
    # Not implemented.
    exit 1
  fi
}


download_and_verify_checksums() {
  local install_type="$1"
  local version="$2"
  local tmp_download_dir="$3"

  if [ "${NODEJS_CHECK_SIGNATURES}" == "no" ]; then
    return 0
  fi

  ## Seems nodejs.org started with around 0.10.0 to release properly signed SHA2-256 checksum files.
  if verlte "0.10.0" "$version"
  then
    echo "$tmp_download_dir"
    local signed_checksum_file="$tmp_download_dir/SHASUMS256.txt.asc"
    local signed_checksum_download_url="$(get_signed_checksum_download_url "$install_type" "$version")"
    if [ -z "${signed_checksum_download_url}" ]; then
      if [ "${NODEJS_CHECK_SIGNATURES}" == "strict" ]; then
        echo "$version did not provide signed checksums or support for them has not been implemented and NODEJS_CHECK_SIGNATURES=strict is set. Exiting." >&2
        exit 1
      else
        echo "$version did not provide signed checksums or support for them has not been implemented. Continue without signature checking." >&2
        return 0
      fi
    fi
    download_file "${signed_checksum_download_url}" "$signed_checksum_file"

    local gnugp_verify_command_name="$(command -v gpg gpg2 | head -n 1)"
    if [ -z "${gnugp_verify_command_name}" ]; then
      echo "You should install GnuPG to verify the authenticity of the downloaded archives: https://www.gnupg.org/" >&2
      exit 1
    fi

    (
      if [ -z "${GNUPGHOME:-}" ] && [ -d "$HOME/.asdf/keyrings/nodejs" ]; then
          export GNUPGHOME="$HOME/.asdf/keyrings/nodejs"
      fi

      local authentic_checksum_file="$tmp_download_dir/authentic_SHASUMS256.txt"
      if ! $gnugp_verify_command_name --verify "$signed_checksum_file"; then
        echo "Authenticity of checksum file can not be assured. Exiting." >&2
        exit 1
      fi
      $gnugp_verify_command_name --output "${authentic_checksum_file}" --decrypt "$signed_checksum_file" 2>/dev/null
    )
  elif [ "${NODEJS_CHECK_SIGNATURES}" == "strict" ]; then
    echo "$version did not provide signed checksums or support for them has not been implemented and NODEJS_CHECK_SIGNATURES=strict is set. Exiting." >&2
    exit 1
  fi
}


verify_archive() {
  local tmp_download_dir="$1"

  local authentic_checksum_file="$tmp_download_dir/authentic_SHASUMS256.txt"

  if [ "${NODEJS_CHECK_SIGNATURES}" == "no" ]; then
    return 0
  fi

  if [ "${NODEJS_CHECK_SIGNATURES}" == "yes" ] && [ ! -e "${authentic_checksum_file}" ]; then
    return 0
  fi

  if verlte "0.10.0" "$version"
  then
    local archive_file_name="$(basename "$(get_download_url "$install_type" "$version")")"

    (
      cd "${tmp_download_dir}"
      if ! sha256sum --check <(grep "\s$archive_file_name$" "${authentic_checksum_file}"); then
        echo "Authenticity package archive can not be assured. Exiting." >&2
        exit 1
      fi
    )
  fi
}


## https://stackoverflow.com/questions/4023830/how-compare-two-strings-in-dot-separated-version-format-in-bash/4024263#4024263
verlte() {
  [  "$1" = "$(echo -e "$1\n$2" | sort -V | head -n1)" ]
}


install_nodejs "$ASDF_INSTALL_TYPE" "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"