#!/bin/sh
set -e

# ANSI color codes — empty when stdout/stderr is not a terminal
if [ -t 2 ]; then
  BOLD='\033[1m'
  DIM='\033[2m'
  CYAN='\033[36m'
  GREEN='\033[32m'
  YELLOW='\033[33m'
  RESET='\033[0m'
else
  BOLD='' DIM='' CYAN='' GREEN='' YELLOW='' RESET=''
fi

INSTALL_CMD="nix profile add 'https://kepr.uk/nina/archive/HEAD.tar.gz#nina'"

banner() {
  printf >&2 '\n'
  printf >&2 "${CYAN}        _${RESET}\n"
  printf >&2 "${CYAN}  _ __ (_)_ __   __ _${RESET}\n"
  printf >&2 "${CYAN} | '_ \\| | '_ \\ / _\` |${RESET}\n"
  printf >&2 "${CYAN} | | | | | | | | (_| |${RESET}\n"
  printf >&2 "${CYAN} |_| |_|_|_| |_|\\__,_|${RESET}\n"
  printf >&2 '\n'
  printf >&2 "  ${BOLD}NixOS Intuitive Navigation Assistant${RESET}  ${DIM}·${RESET}  ${DIM}kepr.uk/nina${RESET}\n"
  printf >&2 '\n'
}

main() {
  banner

  printf >&2 "  nina is installed directly with nix:\n\n"
  printf >&2 "    ${YELLOW}%s${RESET}\n\n" "$INSTALL_CMD"

  # Always prompt via /dev/tty so this works when piped through curl | sh.
  # /dev/tty's permission bits are readable even with no controlling
  # terminal attached (e.g. CI, provisioning, SSH without a pty) — only an
  # actual open reveals that, so probe it instead of using a plain -r test.
  if ! ( : </dev/tty ) 2>/dev/null; then
    printf >&2 "  No terminal to prompt on — run this yourself when ready:\n\n"
    printf >&2 "    ${YELLOW}%s${RESET}\n\n" "$INSTALL_CMD"
    exit 0
  fi
  printf >&2 "  Run it now? [Y/n] "
  read -r answer </dev/tty
  case "${answer:-y}" in
    [nN]*)
      printf >&2 '\n  Copy the command above and run it whenever you are ready.\n\n'
      exit 0
      ;;
  esac
  printf >&2 '\n'

  nix profile add 'https://kepr.uk/nina/archive/HEAD.tar.gz#nina'

  printf >&2 '\n'
  printf >&2 "  ${GREEN}${BOLD}✓ Thank you for installing nina!${RESET}\n"
  printf >&2 '\n'
  printf >&2 "  ${BOLD}Getting started${RESET}\n\n"
  printf >&2 "    ${CYAN}nina help${RESET}       — explore what nina can do\n"
  printf >&2 "    ${CYAN}nina goodbye${RESET}    — remove nina cleanly if it's not a good fit\n"
  printf >&2 '\n'
  printf >&2 "  ${BOLD}Issues & feedback${RESET}\n\n"
  printf >&2 "    ${DIM}https://${RESET}kepr.uk/nina   ${DIM}— no account required${RESET}\n"
  printf >&2 '\n'
}

main