#!/bin/sh

set -eu

REPOSITORY=${KLACK_REPOSITORY:-Zygimantass/klack}
INSTALL_ROOT=${KLACK_INSTALL_ROOT:-${HOME}/Library/Application Support/Klack}
BIN_DIR=${KLACK_BIN_DIR:-${HOME}/.local/bin}
RELEASE_BASE_URL=${KLACK_RELEASE_BASE_URL:-https://github.com/${REPOSITORY}/releases/download}
LATEST_URL=${KLACK_LATEST_URL:-https://github.com/${REPOSITORY}/releases/latest}
VERSION=${KLACK_VERSION:-}
INSTALL_SLACK=false

say() {
  printf '%s\n' "$*"
}

fail() {
  printf 'klack install: %s\n' "$*" >&2
  exit 1
}

usage() {
  cat <<'EOF'
Install the latest Klack release for macOS.

Usage:
  install.sh [--install] [--version vX.Y.Z]

Options:
  --install         Run `klack install` after installing the Klack runtime.
  --version VERSION Install a specific release tag instead of the latest.
  -h, --help        Show this help.

Environment:
  KLACK_INSTALL_ROOT      Runtime directory (default: ~/Library/Application Support/Klack)
  KLACK_BIN_DIR           Launcher directory (default: ~/.local/bin)
EOF
}

while [ "$#" -gt 0 ]; do
  case "$1" in
    --install)
      INSTALL_SLACK=true
      ;;
    --version)
      [ "$#" -ge 2 ] || fail "--version requires a release tag"
      VERSION=$2
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      fail "unknown argument: $1"
      ;;
  esac
  shift
done

[ "${KLACK_PLATFORM:-$(uname -s)}" = "Darwin" ] || fail "only macOS is currently supported"

DETECTED_ARCH=${KLACK_ARCH:-$(uname -m)}
if [ -z "${KLACK_ARCH:-}" ] && [ "$(sysctl -n sysctl.proc_translated 2>/dev/null || true)" = "1" ]; then
  DETECTED_ARCH=arm64
fi

case "$DETECTED_ARCH" in
  arm64)
    ARCH=arm64
    ;;
  x86_64)
    ARCH=x64
    ;;
  *)
    fail "unsupported architecture: $DETECTED_ARCH"
    ;;
esac

command -v curl >/dev/null 2>&1 || fail "curl is required"
command -v tar >/dev/null 2>&1 || fail "tar is required"
command -v node >/dev/null 2>&1 || fail "Node.js 24 or newer is required: https://nodejs.org/"

NODE_MAJOR=$(node -p 'Number(process.versions.node.split(".")[0])' 2>/dev/null) ||
  fail "could not determine the installed Node.js version"
[ "$NODE_MAJOR" -ge 24 ] || fail "Node.js 24 or newer is required (found $(node --version))"

download() {
  DOWNLOAD_URL=$1
  shift
  case "$DOWNLOAD_URL" in
    https://*)
      curl --proto '=https' --proto-redir '=https' --tlsv1.2 -fsSL --retry 3 "$@" "$DOWNLOAD_URL"
      ;;
    *)
      [ "${KLACK_ALLOW_INSECURE_DOWNLOADS:-}" = "1" ] ||
        fail "refusing non-HTTPS download URL: $DOWNLOAD_URL"
      curl -fsSL --retry 3 "$@" "$DOWNLOAD_URL"
      ;;
  esac
}

if [ -z "$VERSION" ]; then
  VERSION=$(download "$LATEST_URL" -o /dev/null -w '%{url_effective}')
  VERSION=${VERSION%/}
  VERSION=${VERSION##*/}
fi

case "$VERSION" in
  v[0-9]*) ;;
  *) fail "invalid release tag: $VERSION" ;;
esac
case "$VERSION" in
  *[!A-Za-z0-9._-]*) fail "invalid release tag: $VERSION" ;;
esac

ARCHIVE=klack-${VERSION}-darwin-${ARCH}.tar.gz
RELEASE_URL=${RELEASE_BASE_URL}/${VERSION}
TEMP_DIR=$(mktemp -d "${TMPDIR:-/tmp}/klack-install.XXXXXX")
RELEASE_STAGE=
INSTALL_LOCK=
trap 'rm -rf "$TEMP_DIR"; [ -z "$RELEASE_STAGE" ] || rm -rf "$RELEASE_STAGE"; [ -z "$INSTALL_LOCK" ] || rmdir "$INSTALL_LOCK" 2>/dev/null || true' EXIT HUP INT TERM

say "Downloading Klack ${VERSION} for darwin-${ARCH}..."
download "${RELEASE_URL}/${ARCHIVE}" -o "${TEMP_DIR}/${ARCHIVE}"
download "${RELEASE_URL}/checksums.txt" -o "${TEMP_DIR}/checksums.txt"

EXPECTED_CHECKSUM=$(awk -v archive="$ARCHIVE" '$2 == archive || $2 == "*" archive { print $1; exit }' "${TEMP_DIR}/checksums.txt")
[ -n "$EXPECTED_CHECKSUM" ] || fail "checksums.txt has no entry for ${ARCHIVE}"

if command -v shasum >/dev/null 2>&1; then
  ACTUAL_CHECKSUM=$(shasum -a 256 "${TEMP_DIR}/${ARCHIVE}" | awk '{ print $1 }')
elif command -v sha256sum >/dev/null 2>&1; then
  ACTUAL_CHECKSUM=$(sha256sum "${TEMP_DIR}/${ARCHIVE}" | awk '{ print $1 }')
else
  fail "shasum or sha256sum is required to verify the release"
fi
[ "$ACTUAL_CHECKSUM" = "$EXPECTED_CHECKSUM" ] || fail "checksum verification failed for ${ARCHIVE}"

mkdir -p "${TEMP_DIR}/extracted"
tar -xzf "${TEMP_DIR}/${ARCHIVE}" -C "${TEMP_DIR}/extracted"
PACKAGE_ROOT=${TEMP_DIR}/extracted/klack
[ -f "${PACKAGE_ROOT}/dist/cli.cjs" ] || fail "release archive does not contain dist/cli.cjs"
[ -f "${PACKAGE_ROOT}/dist/main.cjs" ] || fail "release archive does not contain dist/main.cjs"
[ -f "${PACKAGE_ROOT}/dist/preload.js" ] || fail "release archive does not contain dist/preload.js"
[ -f "${PACKAGE_ROOT}/dist/sdk.js" ] || fail "release archive does not contain dist/sdk.js"
[ -d "${PACKAGE_ROOT}/plugins" ] || fail "release archive does not contain built-in plugins"
[ -d "${PACKAGE_ROOT}/node_modules" ] || fail "release archive does not contain production dependencies"

RELEASES_DIR=${INSTALL_ROOT}/releases
RELEASE_DIR=${RELEASES_DIR}/${VERSION}
mkdir -p "$RELEASES_DIR" "$BIN_DIR"
LOCK_PATH=${INSTALL_ROOT}/.install-lock
mkdir "$LOCK_PATH" 2>/dev/null || fail "another Klack installation is already running"
INSTALL_LOCK=$LOCK_PATH

if [ -e "$RELEASE_DIR" ]; then
  if [ ! -f "${RELEASE_DIR}/dist/cli.cjs" ] ||
    [ ! -f "${RELEASE_DIR}/dist/main.cjs" ] ||
    [ ! -f "${RELEASE_DIR}/dist/preload.js" ] ||
    [ ! -f "${RELEASE_DIR}/dist/sdk.js" ] ||
    [ ! -d "${RELEASE_DIR}/plugins" ] ||
    [ ! -d "${RELEASE_DIR}/node_modules" ]; then
    fail "existing release is incomplete; remove ${RELEASE_DIR} and re-run the installer"
  fi
  say "Klack ${VERSION} is already downloaded."
else
  RELEASE_STAGE=$(mktemp -d "${RELEASES_DIR}/.staging.XXXXXX")
  chmod +x "${PACKAGE_ROOT}/dist/cli.cjs"
  mv "$PACKAGE_ROOT" "${RELEASE_STAGE}/klack"
  mv "${RELEASE_STAGE}/klack" "$RELEASE_DIR"
  rmdir "$RELEASE_STAGE"
  RELEASE_STAGE=
fi

LAUNCHER=${BIN_DIR}/klack
if [ -e "$LAUNCHER" ] || [ -L "$LAUNCHER" ]; then
  EXISTING_TARGET=$(readlink "$LAUNCHER" 2>/dev/null || true)
  [ "$EXISTING_TARGET" = "${INSTALL_ROOT}/current/dist/cli.cjs" ] ||
    fail "refusing to replace existing launcher: ${LAUNCHER}"
fi

ln -sfn "releases/${VERSION}" "${INSTALL_ROOT}/current"
ln -sfn "${INSTALL_ROOT}/current/dist/cli.cjs" "$LAUNCHER"

say "Klack ${VERSION} installed in ${RELEASE_DIR}"
say "Launcher: ${LAUNCHER}"

case ":${PATH}:" in
  *:"${BIN_DIR}":*) ;;
  *) say "Add ${BIN_DIR} to PATH to run klack directly." ;;
esac

if [ "$INSTALL_SLACK" = true ]; then
  say "Installing Klack into Slack..."
  "$LAUNCHER" install
else
  say "Quit Slack completely, then run:"
  say "  ${LAUNCHER} install"
fi