#!/bin/sh
# TermTree installer for macOS and Linux.
#
#   curl -fsSL https://termtree.com/install.sh | sh
#
# Windows is not covered by this script — download the MSI from
# https://termtree.com/download instead.
#
# ---------------------------------------------------------------------------
# Artifacts are served from termtree.com by the `/download/termtree/**` Firebase
# rewrite onto the updater-server (taskhub#659), which 302s to the CDN. The
# Download *page* at /download is a static file and is unaffected — Firebase
# rewrites only fire when no static file matches.
#
# Exercised on macOS 15.7.4 (universal tar.gz), Ubuntu 22.04 amd64 (.deb, as
# root without sudo), Fedora 40 (.rpm), Alpine 3.20 (AppImage fallback), and
# Ubuntu aarch64 (the unsupported-architecture guard).
# ---------------------------------------------------------------------------

set -eu

BASE_URL="${TERMTREE_DOWNLOAD_BASE:-https://termtree.com/download/termtree}"
DOWNLOAD_PAGE="https://termtree.com/download"

# Where the macOS .app is installed. Empty means the default: /Applications,
# falling back to ~/Applications when /Applications is not writable. Set it to
# install somewhere else, or to exercise this branch without touching a real
# install -- replacing /Applications/TermTree.app while it is running swaps the
# bundle underneath a live process.
INSTALL_DIR="${TERMTREE_INSTALL_DIR:-}"

info()  { printf '%s\n' "$*"; }
warn()  { printf '%s\n' "$*" >&2; }
die()   { printf 'error: %s\n' "$*" >&2; exit 1; }

need() {
  command -v "$1" >/dev/null 2>&1 || die "\`$1\` is required but was not found."
}

# Resolve how to escalate for a package install, BEFORE anything is downloaded.
# Hardcoding `sudo` fails on the systems that need it least: running as root in
# a container, a minimal server, or a provisioning script, where sudo is often
# not installed at all.
escalate() {
  if [ "$(id -u)" -eq 0 ]; then
    SUDO=""
  elif command -v sudo >/dev/null 2>&1; then
    SUDO="sudo"
  else
    die "This install needs root and \`sudo\` was not found. Re-run as root, or install the package yourself from $DOWNLOAD_PAGE"
  fi
}

# Whether $1 starts with the ELF magic number. A truncated download or an HTML
# error page served as 200 both fail this; a real AppImage passes.
is_elf() {
  [ -s "$1" ] || return 1
  magic="$(dd if="$1" bs=4 count=1 2>/dev/null | od -An -tx1 | tr -d ' \n')"
  [ "$magic" = "7f454c46" ]
}

# Decide where the .app goes, BEFORE anything is downloaded, so an unusable
# destination costs nothing. Sets $target.
resolve_macos_target() {
  if [ -n "$INSTALL_DIR" ]; then
    # An explicit choice is honoured or fails loudly -- silently redirecting it
    # would put the app somewhere the caller did not ask for.
    mkdir -p "$INSTALL_DIR" 2>/dev/null ||
      die "Could not create install directory: $INSTALL_DIR"
    [ -w "$INSTALL_DIR" ] || die "Install directory is not writable: $INSTALL_DIR"
    target="$INSTALL_DIR/TermTree.app"
  else
    target="/Applications/TermTree.app"
    if [ ! -w /Applications ]; then
      target="$HOME/Applications/TermTree.app"
      mkdir -p "$HOME/Applications" 2>/dev/null ||
        die "Could not create $HOME/Applications"
      warn "/Applications is not writable; installing to $HOME/Applications instead."
    fi
  fi
}

# Download $1 (url) to $2 (destination path).
fetch() {
  url="$1"
  dest="$2"
  info "Downloading $url"
  if command -v curl >/dev/null 2>&1; then
    curl -fSL --proto '=https' --connect-timeout 30 --retry 3 \
      --progress-bar -o "$dest" "$url"
  elif command -v wget >/dev/null 2>&1; then
    # BusyBox wget (Alpine, which also ships no curl) rejects --show-progress,
    # and prints a progress bar of its own when not silenced. Probe rather than
    # assume: GNU wget is silent without it.
    if wget --help 2>&1 | grep -q -- --show-progress; then
      wget -q --show-progress -O "$dest" "$url"
    else
      wget -O "$dest" "$url"
    fi
  else
    die "Either \`curl\` or \`wget\` is required."
  fi
}

WORKDIR=""
cleanup() { [ -n "$WORKDIR" ] && rm -rf "$WORKDIR"; }
trap cleanup EXIT INT TERM

WORKDIR="$(mktemp -d)"

os="$(uname -s)"
arch="$(uname -m)"

install_macos() {
  # One universal build covers Intel and Apple Silicon, so architecture is not
  # part of the URL. The tar.gz is used rather than the DMG because it installs
  # without mounting a disk image or requiring a GUI session.
  need tar
  resolve_macos_target
  archive="$WORKDIR/TermTree.tar.gz"
  fetch "$BASE_URL/Darwin/universal/tar.gz" "$archive"

  info "Extracting"
  tar -xzf "$archive" -C "$WORKDIR"

  app="$(find "$WORKDIR" -maxdepth 2 -name 'TermTree.app' -print -quit)"
  [ -n "$app" ] || die "TermTree.app was not found in the downloaded archive."

  if [ -e "$target" ]; then
    info "Replacing existing installation at $target"
    rm -rf "$target"
  fi
  mv "$app" "$target"

  # Only LaunchServices sets com.apple.quarantine, so an archive fetched by
  # curl or wget carries none and this is a no-op for the piped one-liner. It
  # matters when someone downloads the tarball in a browser and runs the script
  # against it, where the attribute would make first launch fail with a
  # damaged-app warning instead of the normal prompt.
  if command -v xattr >/dev/null 2>&1; then
    xattr -dr com.apple.quarantine "$target" 2>/dev/null || true
  fi

  info ""
  info "TermTree installed to $target"
  case "$target" in
    /Applications/*|"$HOME"/Applications/*)
      info "Launch it from Spotlight, or run: open -a TermTree" ;;
    *)
      info "Launch it with: open \"$target\"" ;;
  esac
}

install_linux() {
  case "$arch" in
    x86_64|amd64) ;;
    *) die "Linux builds are available for x86_64 only (this machine is $arch). See $DOWNLOAD_PAGE" ;;
  esac

  if command -v apt-get >/dev/null 2>&1 && command -v dpkg >/dev/null 2>&1; then
    escalate
    pkg="$WORKDIR/termtree.deb"
    fetch "$BASE_URL/Ubuntu/amd64/deb" "$pkg"
    info "Installing"
    $SUDO apt-get install -y "$pkg"
    info ""
    info "TermTree installed. Launch it from your application menu, or run: termtree"
    return
  fi

  if command -v dnf >/dev/null 2>&1; then
    escalate
    pkg="$WORKDIR/termtree.rpm"
    fetch "$BASE_URL/Ubuntu/amd64/rpm" "$pkg"
    info "Installing"
    $SUDO dnf install -y "$pkg"
    info ""
    info "TermTree installed. Launch it from your application menu, or run: termtree"
    return
  fi

  # No supported package manager — fall back to the AppImage, which needs no
  # root and no distro-specific packaging.
  [ -n "${HOME:-}" ] || die "HOME is not set; cannot choose an install directory."
  bindir="${XDG_BIN_HOME:-$HOME/.local/bin}"
  mkdir -p "$bindir" || die "Could not create $bindir"
  target="$bindir/termtree"

  # Stage, verify, then swap -- the same shape the macOS and package branches
  # use. Downloading onto $target directly meant a truncated transfer left the
  # user's working binary as an executable stub, and a proxy interstitial served
  # as 200 was chmod +x'd and reported as a successful install.
  staged="$WORKDIR/termtree.appimage"
  fetch "$BASE_URL/Ubuntu/amd64/appimage" "$staged"
  is_elf "$staged" || die "The downloaded file is not a Linux executable. A proxy or captive portal may have replaced it. Try again, or download from $DOWNLOAD_PAGE"
  chmod +x "$staged"
  mv "$staged" "$target"

  info ""
  info "TermTree installed to $target"
  case ":$PATH:" in
    *":$bindir:"*) info "Launch it with: termtree" ;;
    *) warn "$bindir is not on your PATH. Add it, or run TermTree with: $target" ;;
  esac
  info ""
  info "The AppImage needs FUSE. If it fails to start, install it:"
  info "  Debian/Ubuntu:  sudo apt install libfuse2"
  info "  Fedora:         sudo dnf install fuse"
}

case "$os" in
  Darwin) install_macos ;;
  Linux)  install_linux ;;
  *)      die "Unsupported platform: $os. Downloads for all platforms are at $DOWNLOAD_PAGE" ;;
esac