install.sh

#!/bin/bash
set -euo pipefail

function run() {
  declare TALISMAN_BINARY_NAME

  E_UNSUPPORTED_ARCH=5

  DEBUG=${DEBUG:-''}
  VERSION=${VERSION:-'latest'}
  INSTALL_ORG_REPO=${INSTALL_ORG_REPO:-'thoughtworks/talisman'}
  INSTALL_LOCATION=${INSTALL_LOCATION:-'/usr/local/bin'}

  TEMP_DIR=$(mktemp -d 2>/dev/null || mktemp -d -t 'talisman_setup')
  # shellcheck disable=SC2064
  trap "rm -r $TEMP_DIR" EXIT
  chmod 0700 "$TEMP_DIR"

  function echo_error() {
    echo -ne "$(tput setaf 1)" >&2
    echo "$1" >&2
    echo -ne "$(tput sgr0)" >&2
  }

  function echo_debug() {
    [[ -z "$DEBUG" ]] && return
    echo -ne "$(tput setaf 3)" >&2
    echo "$1" >&2
    echo -ne "$(tput sgr0)" >&2
  }

  function echo_success() {
    echo -ne "$(tput setaf 2)"
    echo "$1" >&2
    echo -ne "$(tput sgr0)"
  }

  function operating_system() {
    OS=$(uname -s)
    case $OS in
    "Linux")
      echo "linux"
      ;;
    "Darwin")
      echo "darwin"
      ;;
    MINGW32_NT-*)
      echo "windows"
      ;;
    MINGW64_NT-*)
      echo "windows"
      ;;
    MSYS_NT-*)
      echo "windows"
      ;;
    *)
      echo_error "Talisman currently only supports Windows, Linux and MacOS(darwin) systems."
      echo_error "If this is a problem for you, please open an issue: https://github.com/$INSTALL_ORG_REPO/issues/new"
      exit $E_UNSUPPORTED_ARCH
      ;;
    esac
  }

  function set_talisman_binary_name() {
    # based on OS (linux/darwin) and ARCH(32/64 bit)
    declare SUFFIX
    SUFFIX=$(operating_system)
    ARCH=$(uname -m)
    case $ARCH in
    "x86_64")
      SUFFIX="${SUFFIX}_amd64"
      ;;
    "i686" | "i386")
      SUFFIX="${SUFFIX}_386"
      ;;
    "arm64" | "aarch64")
      SUFFIX="${SUFFIX}_arm64"
      ;;
    *)
      echo_error "Talisman currently only supports x86 and x86_64 and arm64 architectures."
      echo_error "If this is a problem for you, please open an issue: https://github.com/$INSTALL_ORG_REPO/issues/new"
      exit $E_UNSUPPORTED_ARCH
      ;;
    esac

    TALISMAN_BINARY_NAME="talisman_$SUFFIX"
    if [[ $SUFFIX == *"windows"* ]]; then
      TALISMAN_BINARY_NAME="$TALISMAN_BINARY_NAME.exe"
    fi
  }

  function download() {
    OBJECT=$1
    DOWNLOAD_URL=$(curl -Ls https://api.github.com/repos/"$INSTALL_ORG_REPO"/releases/latest |
       grep download_url | awk '{print $2}' | tr -d '"' | grep "$OBJECT")

    echo_debug "Downloading $OBJECT from $DOWNLOAD_URL"
    curl --location --silent "$DOWNLOAD_URL" >"$TEMP_DIR/$OBJECT"
  }

  function verify_checksum() {
    FILE_NAME=$1
    CHECKSUM_FILE_NAME='checksums'
    echo_debug "Verifying checksum for $FILE_NAME"
    download $CHECKSUM_FILE_NAME

    pushd "$TEMP_DIR" >/dev/null 2>&1
    grep "$TALISMAN_BINARY_NAME" $CHECKSUM_FILE_NAME >$CHECKSUM_FILE_NAME.single

    if ! command -v shasum &> /dev/null; then
      sha256sum -c $CHECKSUM_FILE_NAME.single
    else
      shasum -a 256 -c $CHECKSUM_FILE_NAME.single
    fi
    popd >/dev/null 2>&1
    echo_debug "Checksum verification successfully!"
    echo
  }

  function download_talisman_binary() {
    download "$TALISMAN_BINARY_NAME"
    verify_checksum "$TALISMAN_BINARY_NAME"
  }

  function setup_talisman() {
    if (touch "$INSTALL_LOCATION/talisman" &>/dev/null); then
      cp "$TEMP_DIR/$TALISMAN_BINARY_NAME" "$INSTALL_LOCATION/talisman"
      chmod +x "$INSTALL_LOCATION/talisman"
    elif (which sudo &>/dev/null); then
      sudo cp "$TEMP_DIR/$TALISMAN_BINARY_NAME" "$INSTALL_LOCATION/talisman"
      sudo chmod +x "$INSTALL_LOCATION/talisman"
    else
      echo_error "Insufficient permission to install to $INSTALL_LOCATION"
      exit 126
    fi
  }

  set_talisman_binary_name

  echo_success "Downloading talisman binary"
  download_talisman_binary
  setup_talisman
}

run