#!/usr/bin/env bash
#
# booth.sh — operate the parking stack on the booth PC (Ubuntu).
#
# Wraps the three compose files (base + a dev/prod override) so the operator runs
# one command instead of a long `docker compose -f … -f … --env-file …` line.
#
#   ./scripts/booth.sh up        # start the stack (detached)
#   ./scripts/booth.sh update    # pull newer images + recreate (the "there are
#                                #   new images" case) — see `update` below
#   ./scripts/booth.sh down      # stop the stack
#   ./scripts/booth.sh restart   # restart without pulling
#   ./scripts/booth.sh status    # what's running
#   ./scripts/booth.sh logs      # follow logs (Ctrl-C to stop)
#   ./scripts/booth.sh ps|pull|config|exec …
#
# Environment is PROD by default (the booth runs prod: pull pinned registry images,
# Caddy on :80, fast_alpr). Override with ENV=dev for a local build/dev run:
#   ENV=dev ./scripts/booth.sh up
#
# Config comes from an .env file next to the compose files (REGISTRY, TAG,
# JWT_SECRET, …). Copy .env.example → .env and fill it in. See
# wiki/decisions/container-deployment.md.

set -euo pipefail

# --- locate the repo (this script lives in <repo>/scripts) --------------------
SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
REPO_DIR="$(cd -- "$SCRIPT_DIR/.." && pwd)"
cd "$REPO_DIR"

# --- environment selection (prod by default; the booth is prod) ---------------
ENV="${ENV:-prod}"
case "$ENV" in
  prod|production) ENV=prod; OVERRIDE="docker-compose.prod.yml" ;;
  dev|development) ENV=dev;  OVERRIDE="docker-compose.dev.yml"  ;;
  *) echo "ERROR: ENV must be 'prod' or 'dev' (got '$ENV')." >&2; exit 2 ;;
esac

BASE="docker-compose.yml"
ENV_FILE="${ENV_FILE:-.env}"

# --- colours (only when attached to a terminal) -------------------------------
if [ -t 1 ]; then
  R="$(printf '\033[31m')"; G="$(printf '\033[32m')"; Y="$(printf '\033[33m')"
  B="$(printf '\033[1m')"; N="$(printf '\033[0m')"
else
  R=""; G=""; Y=""; B=""; N=""
fi
info() { printf '%s==>%s %s\n' "$B" "$N" "$*"; }
warn() { printf '%s!! %s%s\n' "$Y" "$*" "$N" >&2; }
die()  { printf '%sERROR:%s %s\n' "$R" "$N" "$*" >&2; exit 1; }

usage() {
  sed -n '3,30p' "$0" | sed 's/^# \{0,1\}//'
  exit "${1:-0}"
}

# --- preflight (only for commands that actually talk to Docker) ---------------
# Deferred into a function so `help`/usage works with no Docker and no .env.
ENV_ARGS=()
DC=()
preflight() {
  command -v docker >/dev/null 2>&1 || die "docker is not installed or not on PATH."
  # Prefer the v2 plugin (`docker compose`); fall back to legacy `docker-compose`.
  if docker compose version >/dev/null 2>&1; then
    DC=(docker compose)
  elif command -v docker-compose >/dev/null 2>&1; then
    DC=(docker-compose)
  else
    die "Docker Compose v2 plugin not found ('docker compose'). Install docker-compose-plugin."
  fi

  [ -f "$BASE" ]     || die "missing $BASE in $REPO_DIR"
  [ -f "$OVERRIDE" ] || die "missing $OVERRIDE in $REPO_DIR"

  # An .env is required for prod (JWT_SECRET et al. have no safe default); optional
  # for dev (we inject a benign local secret below). Pass --env-file only when it
  # exists so dev works without one.
  if [ -f "$ENV_FILE" ]; then
    ENV_ARGS=(--env-file "$ENV_FILE")
  elif [ "$ENV" = "prod" ]; then
    die "no $ENV_FILE found. Copy .env.example to $ENV_FILE and set JWT_SECRET/REGISTRY/TAG. (prod has no safe defaults.)"
  else
    # The BASE compose file makes JWT_SECRET shell-required (${JWT_SECRET:?}), which
    # the dev override's service-level default can't satisfy. For a dev run with no
    # .env, inject the same benign 32-char local secret the dev override documents so
    # `up`/`config` work out of the box. NEVER do this for prod (the die above).
    warn "no $ENV_FILE found — injecting the documented local-dev JWT_SECRET (dev only)."
    : "${JWT_SECRET:=localdevsecret0123456789abcdef0123}"
    export JWT_SECRET
  fi
}

# The assembled compose invocation every subcommand builds on (runs preflight once).
compose() { "${DC[@]}" -f "$BASE" -f "$OVERRIDE" "${ENV_ARGS[@]}" "$@"; }

# --- subcommands --------------------------------------------------------------
cmd="${1:-}"; [ "$#" -gt 0 ] && shift || true

# Help/usage short-circuits before any Docker or .env requirement.
case "$cmd" in ""|-h|--help|help) usage 0 ;; esac

# Reject an unknown command up front (before preflight) so a typo gets a clear
# "unknown command" rather than a confusing "no .env" from the prod env check.
case "$cmd" in
  up|start|update|upgrade|down|stop|restart|pull|status|ps|logs|config|exec) ;;
  *) warn "unknown command: $cmd"; usage 1 ;;
esac

preflight

case "$cmd" in
  up|start)
    info "Starting the parking stack ($B$ENV$N) …"
    compose up -d "$@"
    info "Up. ${G}$(compose ps --services 2>/dev/null | tr '\n' ' ')${N}"
    info "Booth UI: prod → http://<booth-ip>/  ·  dev → http://<booth-ip>:3000/"
    ;;

  update|upgrade)
    # The "I know there are new images" path: pull the moving branch tag, then
    # recreate only what changed. Compose recreates a service whose image digest
    # moved; unchanged services (and the named volumes — the SQLite DB!) are left
    # alone. Old image layers are pruned afterwards to reclaim disk.
    [ "$ENV" = "prod" ] || warn "update on ENV=$ENV: dev builds locally, so 'pull' may be a no-op. Use 'up --build' to rebuild dev."
    info "Pulling newer images for the ${B}$ENV_FILE${N} TAG …"
    compose pull
    info "Recreating changed services (volumes/DB preserved) …"
    compose up -d --remove-orphans
    info "Pruning dangling image layers …"
    docker image prune -f >/dev/null || true
    info "${G}Update complete.${N} Running:"
    compose ps
    ;;

  down|stop)
    info "Stopping the parking stack ($ENV) …"
    # NOTE: never pass -v here — that would delete the parking-data volume (the
    # signed event ledger). Volumes are intentionally preserved across down/up.
    compose down "$@"
    ;;

  restart)
    info "Restarting (no pull) …"
    compose restart "$@"
    ;;

  pull)
    info "Pulling images only (no recreate) …"
    compose pull "$@"
    ;;

  status|ps)
    compose ps "$@"
    ;;

  logs)
    # Follow by default; pass a service name to scope, e.g. `logs server`.
    compose logs -f --tail=200 "$@"
    ;;

  config)
    # Render the merged, variable-substituted compose config (debugging).
    compose config "$@"
    ;;

  exec)
    [ "$#" -ge 1 ] || die "usage: $0 exec <service> [cmd…]  (e.g. exec server sh)"
    compose exec "$@"
    ;;
esac