install.sh

#!/bin/sh
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# install.sh — fetch the latest promptzero release and drop it on $PATH.
#
# This script intentionally does one thing: bootstrap a fresh install.
# Once promptzero is on your system, use its own subcommands to stay
# current:
#
#   promptzero version --check   — see if a newer release is available
#   promptzero upgrade           — replace yourself with the latest
#
# Usage:
#   sh install.sh                         Install the latest release.
#   sh install.sh --version vX.Y.Z        Pin a specific release.
#   sh install.sh --prefix <dir>          Install directory (see below).
#   sh install.sh --help                  This text.
#
# Environment overrides:
#   PROMPTZERO_VERSION   Same effect as --version.
#   PROMPTZERO_PREFIX    Same effect as --prefix.
#
# Install directory resolution (first writable wins):
#   1. --prefix / PROMPTZERO_PREFIX
#   2. $XDG_BIN_HOME
#   3. $HOME/.local/bin
#   4. /usr/local/bin
#
# Supports Linux and macOS on amd64/arm64. Windows users should download
# the .zip from https://github.com/xunholy/promptzero/releases.
#
# Requires: sh, curl, tar, sha256sum (Linux) or shasum (macOS).

set -eu

REPO="xunholy/promptzero"
BINARY="promptzero"
CLEANUP_TMP=""

cleanup() {
  if [ -n "${CLEANUP_TMP:-}" ] && [ -d "${CLEANUP_TMP}" ]; then
    rm -rf "${CLEANUP_TMP}"
  fi
}
trap cleanup EXIT INT TERM

log()  { printf '%s\n' "$*" >&2; }
info() { printf '\033[36m▸\033[0m %s\n' "$*" >&2; }
ok()   { printf '\033[32m✓\033[0m %s\n' "$*" >&2; }
warn() { printf '\033[33m!\033[0m %s\n' "$*" >&2; }
die()  { printf '\033[31m✗\033[0m %s\n' "$*" >&2; exit 1; }

usage() {
  # Print the doc banner (contiguous leading `#` lines after the SPDX
  # marker). Extracting from $0 keeps the help text and the source in
  # sync without a second heredoc to maintain.
  awk 'NR==1 {next}
       /^# SPDX/ {next}
       /^#!/ {next}
       /^#/ {sub(/^# ?/,""); print; next}
       {exit}' "$0"
}

# --- Argument parsing ---------------------------------------------------

VERSION="${PROMPTZERO_VERSION:-}"
PREFIX="${PROMPTZERO_PREFIX:-}"

while [ $# -gt 0 ]; do
  case "$1" in
    --version)
      shift
      [ $# -gt 0 ] || die "--version needs a value"
      VERSION="$1"
      ;;
    --version=*) VERSION="${1#--version=}" ;;
    --prefix)
      shift
      [ $# -gt 0 ] || die "--prefix needs a value"
      PREFIX="$1"
      ;;
    --prefix=*)  PREFIX="${1#--prefix=}" ;;
    -h|--help)   usage; exit 0 ;;
    upgrade|uninstall)
      die "'$1' is no longer handled by install.sh — use 'promptzero $1' instead"
      ;;
    *) usage >&2; die "unknown argument: $1" ;;
  esac
  shift
done

# --- Dependencies & platform detection ---------------------------------

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || die "required command not found: $1"
}

sha256_of() {
  # Portable SHA-256: GNU coreutils ships sha256sum, macOS ships shasum.
  if command -v sha256sum >/dev/null 2>&1; then
    sha256sum "$1" | awk '{print $1}'
  elif command -v shasum >/dev/null 2>&1; then
    shasum -a 256 "$1" | awk '{print $1}'
  else
    die "need sha256sum or shasum for checksum verification"
  fi
}

detect_platform() {
  os="$(uname -s 2>/dev/null | tr '[:upper:]' '[:lower:]')"
  arch="$(uname -m 2>/dev/null)"
  case "$os" in
    linux)  OS=linux ;;
    darwin) OS=darwin ;;
    mingw*|msys*|cygwin*)
      die "Windows is not supported by install.sh — download the .zip from https://github.com/${REPO}/releases"
      ;;
    *) die "unsupported OS: $os" ;;
  esac
  case "$arch" in
    x86_64|amd64)   ARCH=amd64 ;;
    aarch64|arm64)  ARCH=arm64 ;;
    *) die "unsupported architecture: $arch (expected amd64 or arm64)" ;;
  esac
}

# --- Install-dir resolution --------------------------------------------

writable_dir() {
  d="$1"
  [ -z "$d" ] && return 1
  if [ -d "$d" ] && [ -w "$d" ]; then return 0; fi
  parent="$(dirname "$d")"
  [ -d "$parent" ] && [ -w "$parent" ]
}

resolve_prefix() {
  if [ -n "$PREFIX" ]; then
    printf '%s' "$PREFIX"
    return
  fi
  for d in "${XDG_BIN_HOME:-}" "$HOME/.local/bin" "/usr/local/bin"; do
    if writable_dir "$d"; then
      printf '%s' "$d"
      return
    fi
  done
  die "no writable install dir found — try: sh install.sh --prefix ~/bin"
}

# --- Version resolution -------------------------------------------------

normalise_version() {
  v="$1"
  case "$v" in
    v*) printf '%s' "$v" ;;
    *)  printf 'v%s' "$v" ;;
  esac
}

# latest_version follows the /releases/latest redirect on github.com and
# pulls the tag off the end of the final URL. Unauthenticated, no rate
# limit, no JSON parsing — the same approach the CLI uses internally.
latest_version() {
  url="$(curl -fsSIL -o /dev/null -w '%{url_effective}' \
         "https://github.com/${REPO}/releases/latest" 2>/dev/null)" \
    || die "failed to resolve latest version (network error)"
  tag="${url##*/}"
  case "$tag" in
    v*) printf '%s' "$tag" ;;
    *)  die "couldn't resolve latest release (redirect url: $url)" ;;
  esac
}

resolve_version() {
  if [ -n "$VERSION" ]; then
    normalise_version "$VERSION"
    return
  fi
  latest_version
}

# --- PATH hint ----------------------------------------------------------

check_path() {
  dir="$1"
  case ":${PATH:-}:" in
    *":${dir}:"*) return 0 ;;
  esac
  warn "${dir} is not on your PATH."
  log  ""
  log  "    Add this to your shell profile (~/.bashrc, ~/.zshrc, ~/.profile):"
  log  ""
  log  "        export PATH=\"${dir}:\$PATH\""
  log  ""
}

# --- Install flow -------------------------------------------------------

detect_platform
need_cmd curl
need_cmd tar

prefix="$(resolve_prefix)"
target="$(resolve_version)"
bin_path="${prefix}/${BINARY}"

info "target : ${target}"
info "host   : ${OS}/${ARCH}"
info "prefix : ${prefix}"

asset="${BINARY}-${OS}-${ARCH}.tar.gz"
base="https://github.com/${REPO}/releases/download/${target}"

CLEANUP_TMP="$(mktemp -d 2>/dev/null || mktemp -d -t promptzero)"

info "downloading ${asset}"
curl -fsSL -o "${CLEANUP_TMP}/${asset}" "${base}/${asset}" \
  || die "download failed: ${base}/${asset}"
info "downloading checksums.txt"
curl -fsSL -o "${CLEANUP_TMP}/checksums.txt" "${base}/checksums.txt" \
  || die "download failed: ${base}/checksums.txt"

info "verifying sha256"
expected="$(awk -v f="$asset" '$2 == f || $2 == "*"f {print $1; exit}' \
            "${CLEANUP_TMP}/checksums.txt")"
[ -n "$expected" ] || die "no checksum entry for ${asset} in checksums.txt"
got="$(sha256_of "${CLEANUP_TMP}/${asset}")"
if [ "$got" != "$expected" ]; then
  die "checksum mismatch for ${asset}
  expected: ${expected}
  got:      ${got}"
fi

info "extracting"
( cd "${CLEANUP_TMP}" && tar xzf "${asset}" )
src="${CLEANUP_TMP}/${BINARY}-${OS}-${ARCH}"
[ -f "$src" ] || die "binary '${BINARY}-${OS}-${ARCH}' not found after extract"
chmod +x "$src"

info "installing to ${bin_path}"
mkdir -p "$prefix"
mv "$src" "$bin_path"

got_ver="$("$bin_path" --version 2>/dev/null | awk '{print $2; exit}')" || true
if [ -n "$got_ver" ] && [ "$got_ver" != "$target" ]; then
  warn "installed binary reports ${got_ver}, expected ${target}"
fi

ok "installed ${BINARY} ${target} → ${bin_path}"
log ""
log "  Stay current with:"
log "      promptzero version --check"
log "      promptzero upgrade"
log ""
check_path "$prefix"