#!/bin/sh
# Big MacD installer — https://join.bigmacd.com/install
#
# Carries no token and never sees an invite code (spec §4 step 3). It checks this Mac, downloads
# the menu-bar app and its detached signature, verifies the signature against the release key
# pinned below, installs the app into ~/Applications and opens it. Re-running it updates the app.
# Test overrides: BIGMACD_BASE_URL, BIGMACD_INSTALL_DIR, BIGMACD_NO_OPEN, BIGMACD_NO_QUIT (never
# quit a running app), BIGMACD_MACOS_VERSION.
# Read it before you run it: curl -fsSL https://join.bigmacd.com/install | less
set -eu

BASE_URL="${BIGMACD_BASE_URL:-https://join.bigmacd.com}"
INSTALL_DIR="${BIGMACD_INSTALL_DIR:-$HOME/Applications}"
APP=BigMacD.app
MIN_MACOS_MAJOR=14 # the app uses macOS 14 window APIs (Plan 7b)

# Release signing key (ECDSA P-256, AWS KMS in bigmacd-release). Key ID: alias/bigmacd-release-prod
RELEASE_KEY='-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEdK0jh2zYA3uZ/Jtp+5EZdRjmpWu7
sX64WLOANgEqHGwk52jmKTADq8nD7slqjXETbo3VX8UwkiDqCnq5xcnmpg==
-----END PUBLIC KEY-----'

die() { printf 'Big MacD installer: %s\n' "$1" >&2; exit 1; }

main() {
  [ "$(uname -s)" = Darwin ] || die "this installer is for macOS only."
  [ "$(sysctl -n hw.optional.arm64 2>/dev/null || echo 0)" = 1 ] || die "Big MacD needs a Mac with Apple silicon (M1 or later)."
  ver="${BIGMACD_MACOS_VERSION:-$(sw_vers -productVersion)}" # override for tests only
  major=$(printf '%s' "$ver" | cut -d. -f1)
  [ "$major" -ge "$MIN_MACOS_MAJOR" ] 2>/dev/null || die "Big MacD needs macOS $MIN_MACOS_MAJOR or later (this Mac has $ver)."

  tmp=$(mktemp -d "${TMPDIR:-/tmp}/bigmacd-install.XXXXXX")
  trap 'rm -rf "$tmp"' EXIT
  trap 'exit 130' INT TERM # an interrupt stops the install; the EXIT trap cleans up

  printf 'Downloading Big MacD...\n'
  curl -fsSL -o "$tmp/app.zip" "$BASE_URL/app/latest.zip" || die "download failed. Check your connection and run the command again."
  curl -fsSL -o "$tmp/app.zip.sig" "$BASE_URL/app/latest.zip.sig" || die "download failed. Check your connection and run the command again."

  printf '%s\n' "$RELEASE_KEY" > "$tmp/release.pem"
  /usr/bin/openssl dgst -sha256 -verify "$tmp/release.pem" -signature "$tmp/app.zip.sig" "$tmp/app.zip" >/dev/null 2>&1 \
    || die "signature check failed: the download is not a Big MacD release. Nothing was installed. If a release was just published, run the command again."

  /usr/bin/ditto -x -k "$tmp/app.zip" "$tmp/x" || die "the download is damaged. Nothing was installed."
  [ -d "$tmp/x/$APP" ] || die "the download does not contain $APP. Nothing was installed."
  xattr -dr com.apple.quarantine "$tmp/x/$APP" 2>/dev/null || true

  mkdir -p "$INSTALL_DIR"
  if [ -z "${BIGMACD_NO_QUIT:-}" ] && pgrep -xq BigMacD 2>/dev/null; then
    osascript -e 'quit app "BigMacD"' >/dev/null 2>&1 || true
    sleep 2
  fi
  rm -rf "$INSTALL_DIR/$APP.old"
  [ -d "$INSTALL_DIR/$APP" ] && mv "$INSTALL_DIR/$APP" "$INSTALL_DIR/$APP.old"
  mv "$tmp/x/$APP" "$INSTALL_DIR/$APP"
  rm -rf "$INSTALL_DIR/$APP.old"

  printf 'Installed %s/%s\n' "$INSTALL_DIR" "$APP"
  if [ -z "${BIGMACD_NO_OPEN:-}" ]; then
    open "$INSTALL_DIR/$APP"
  fi
}

# The whole script is one function call, so a download cut short runs nothing.
main "$@"