Bash script to install/update aer

install-aer.sh

#!/bin/bash
set -euo pipefail

AER_HOME="${HOME}/.aer"
BIN_DIR="${AER_HOME}/bin"
TARGET="${BIN_DIR}/aer"
BACKUP="${BIN_DIR}/aer.bak"

REPO_BASE_URL="https://github.com/octoberswimmer/aer-dist"

create_backup() {
  if [[ -f "${TARGET}" ]]; then
    mv -f "${TARGET}" "${BACKUP}"
  fi
}

restore_backup() {
  if [[ -f "${BACKUP}" ]]; then
    echo "Restoring backup..."
    mv -f "${BACKUP}" "${TARGET}"
    echo "Restore complete."
  else
    echo "No backup found to restore."
  fi
}

delete_backup() {
  if [[ -f "${BACKUP}" ]]; then
    rm -f "${BACKUP}"
  fi
}

install_aer() {
  create_backup
  FILE_NAME="aer_darwin_amd64_${VERSION}.zip"

  # Download asset
  cd "${AER_HOME}"
  wget -q "${REPO_BASE_URL}/releases/download/${VERSION}/${FILE_NAME}" -O "${FILE_NAME}"

  # Unzip into bin directory
  unzip -o "${FILE_NAME}" -d "${BIN_DIR}"
  chmod +x "${TARGET}"
  echo "$VERSION" > "${AER_HOME}/version.txt"

  # Remove archive
  rm -f "${FILE_NAME}"

  if "${BIN_DIR}/aer" --version &> /dev/null; then
    echo "AER installed successfully (version ${VERSION})."
    delete_backup
  else
    echo "AER installation failed."
    restore_backup
    exit 1
  fi
}

on_error() {
  echo "Update failed. Attempting to restore previous version..."
  restore_backup
  exit 1
}

trap on_error ERR

# Check required commands
for cmd in curl wget unzip; do
  if ! command -v "$cmd" &> /dev/null; then
    echo "$cmd could not be found. Please install $cmd to proceed."
    exit 1
  fi
done

# Ensure AER_HOME and BIN_DIR exist
if [[ ! -d "${AER_HOME}" ]]; then
  mkdir -p "${BIN_DIR}"
fi

# Determine latest version
VERSION="$(curl -sI "${REPO_BASE_URL}/releases/latest" | grep '^location:' | awk '{print $2}' | tr -d $'\r\n' | awk -F'/' '{print $NF}')"
CURRENT_VERSION=""
if [[ -f "${AER_HOME}/version.txt" ]]; then
  CURRENT_VERSION="$(cat "${AER_HOME}/version.txt")"
fi

if [[ "${VERSION}" == "${CURRENT_VERSION}" ]]; then
  echo "AER is already up to date (version ${VERSION})."
elif [[ -z "${CURRENT_VERSION}" ]]; then
  echo "AER is not installed. Installing version ${VERSION}."
  install_aer
else
  echo "Updating AER from version ${CURRENT_VERSION} to ${VERSION}."
  install_aer
fi


# Add BIN_DIR to PATH if not already present
if ! command -v aer &> /dev/null; then
  # detect which shell is being used
  SHELL_NAME="$(basename "$SHELL")"
  PROFILE_FILE=""
  case "${SHELL_NAME}" in
    bash)
      PROFILE_FILE="${HOME}/.bashrc"
      ;;
    zsh)
      PROFILE_FILE="${HOME}/.zshrc"
      ;;
    *)
      echo "Unsupported shell: ${SHELL_NAME}. Please add ${BIN_DIR} to your PATH manually."
      exit 1
      ;;
  esac

  # update path in profile file
  if ! grep -q "${BIN_DIR}" "${PROFILE_FILE}"; then
    echo "" >> "${PROFILE_FILE}"
    echo "# Added by AER installer" >> "${PROFILE_FILE}"
    echo "export PATH=\"${BIN_DIR}:\$PATH\"" >> "${PROFILE_FILE}"

    echo "Updated ${PROFILE_FILE} to include ${BIN_DIR} in PATH."
    case "${SHELL_NAME}" in
      bash)
        set +u
        source "${PROFILE_FILE}"
        set -u
        ;;
      zsh)
        PATH="${BIN_DIR}:${PATH}"
        echo "Please run 'source ~/.zshrc' or restart your terminal to update your PATH."
        ;;
    esac
  fi
fi