#!/usr/bin/env bash
#
# Install the BookStack MCP server into a Debian/Ubuntu LXC container.
# Run as root, from inside the container, in the directory containing pyproject.toml:
#
#   bash deploy/lxc/install.sh
#
set -euo pipefail

APP_DIR=/opt/bookstack-mcp
CONF_DIR=/etc/bookstack-mcp
SVC_USER=bookstack-mcp
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

log() { printf '\033[1;34m==>\033[0m %s\n' "$*"; }
die() { printf '\033[1;31mERROR:\033[0m %s\n' "$*" >&2; exit 1; }

# Find the project root. Normally this script lives at deploy/lxc/install.sh so
# the root is two levels up, but people often copy the tree around flat, so
# check the obvious candidates rather than assuming.
find_src() {
  local candidate
  for candidate in "$SCRIPT_DIR/../.." "$SCRIPT_DIR/.." "$SCRIPT_DIR" "$PWD"; do
    if [[ -f "$candidate/pyproject.toml" && -d "$candidate/bookstack_mcp" ]]; then
      (cd "$candidate" && pwd)
      return 0
    fi
  done
  return 1
}

if ! SRC_DIR="$(find_src)"; then
  die "Can't find the project source (needs pyproject.toml and a bookstack_mcp/ directory).
     Looked in: $SCRIPT_DIR/../.. , $SCRIPT_DIR/.. , $SCRIPT_DIR , $PWD

     Get the whole project into the container, then run the script from its root:
       git clone <your-repo> /opt/src/bookstack-mcp
       cd /opt/src/bookstack-mcp
       bash deploy/lxc/install.sh"
fi

[[ $EUID -eq 0 ]] || die "Run this as root (or with sudo)."

# The script copies SRC_DIR into APP_DIR, so they must not be the same place.
if [[ "$SRC_DIR" == "$APP_DIR" ]]; then
  die "The source is $APP_DIR, which is also the install target.
     Keep the source somewhere else and let the installer copy it in:
       mkdir -p /opt/src && mv $APP_DIR /opt/src/bookstack-mcp
       cd /opt/src/bookstack-mcp && bash deploy/lxc/install.sh"
fi

log "Installing from $SRC_DIR"

# --- Python version check -------------------------------------------------
# Needs 3.11+. Debian 12/13 and Ubuntu 24.04 are fine; Debian 11 and
# Ubuntu 22.04 ship something older and need a newer python installed first.
log "Checking Python version"
if ! command -v python3 >/dev/null; then
  die "python3 not installed. Try: apt install -y python3 python3-venv"
fi
PY_OK=$(python3 -c 'import sys; print(1 if sys.version_info >= (3,11) else 0)')
if [[ "$PY_OK" != "1" ]]; then
  die "Python $(python3 -V | cut -d' ' -f2) found, but 3.11+ is required.
     Debian 12+/Ubuntu 24.04+ work out of the box. On older releases install a
     newer python3 first (e.g. via deadsnakes) and re-run."
fi

# --- Dependencies ---------------------------------------------------------
log "Installing system packages"
export DEBIAN_FRONTEND=noninteractive
# A single broken third-party repo shouldn't abort the whole install, so the
# update is advisory; only the install itself is allowed to fail the script.
apt-get update -qq || log "apt update reported errors, continuing"
apt-get install -y -qq python3-venv python3-pip ca-certificates >/dev/null

# --- Service user ---------------------------------------------------------
if ! id -u "$SVC_USER" >/dev/null 2>&1; then
  log "Creating service user $SVC_USER"
  useradd --system --home-dir "$APP_DIR" --shell /usr/sbin/nologin "$SVC_USER"
fi

# --- Application ----------------------------------------------------------
log "Installing application to $APP_DIR"
mkdir -p "$APP_DIR"
rm -rf "$APP_DIR/bookstack_mcp"
cp -r "$SRC_DIR/bookstack_mcp" "$APP_DIR/"
cp "$SRC_DIR/pyproject.toml" "$APP_DIR/"

if [[ ! -d "$APP_DIR/venv" ]]; then
  log "Creating virtualenv"
  python3 -m venv "$APP_DIR/venv"
fi

log "Installing Python dependencies (this takes a minute)"
"$APP_DIR/venv/bin/pip" install --quiet --upgrade pip
"$APP_DIR/venv/bin/pip" install --quiet "$APP_DIR"

chown -R "$SVC_USER:$SVC_USER" "$APP_DIR"

# --- Configuration --------------------------------------------------------
mkdir -p "$CONF_DIR"
if [[ ! -f "$CONF_DIR/env" ]]; then
  log "Creating $CONF_DIR/env from the template"
  # systemd EnvironmentFile does not understand quotes or inline comments the
  # way a shell does, so strip comments and blank lines out of the example.
  grep -vE '^\s*(#|$)' "$SRC_DIR/.env.example" > "$CONF_DIR/env"
  NEW_CONFIG=1
else
  log "Keeping existing $CONF_DIR/env"
  NEW_CONFIG=0
fi
chown root:"$SVC_USER" "$CONF_DIR/env"
chmod 640 "$CONF_DIR/env"

# --- systemd --------------------------------------------------------------
log "Installing systemd unit"
UNIT_SRC=""
for candidate in "$SRC_DIR/deploy/lxc/bookstack-mcp.service" "$SCRIPT_DIR/bookstack-mcp.service"; do
  [[ -f "$candidate" ]] && { UNIT_SRC="$candidate"; break; }
done
[[ -n "$UNIT_SRC" ]] || die "Can't find bookstack-mcp.service"
install -m 644 "$UNIT_SRC" /etc/systemd/system/bookstack-mcp.service
systemctl daemon-reload
systemctl enable bookstack-mcp >/dev/null

echo
log "Install complete."
echo
if [[ "$NEW_CONFIG" == "1" ]]; then
  cat <<EOF
Next steps:

  1. Edit the config and fill in your BookStack details:
       nano $CONF_DIR/env

     At minimum: BOOKSTACK_URL, BOOKSTACK_TOKEN_ID, BOOKSTACK_TOKEN_SECRET.
     Generate a Claude Code token with:  openssl rand -hex 32

  2. Start it:
       systemctl start bookstack-mcp
       systemctl status bookstack-mcp
       journalctl -u bookstack-mcp -f

  3. Verify locally (401 with a WWW-Authenticate header is the correct answer
     when auth is enabled):
       curl -i http://127.0.0.1:8080/mcp
EOF
else
  echo "  systemctl restart bookstack-mcp"
fi