#!/usr/bin/env bash
# deploy-container.sh — swap or rollback the flights-web container on the host.
#
# Usage: deploy-container.sh [--dry-run] <swap|rollback>
#
# `swap`     — assumes the new image is tagged flights-web:${GITHUB_SHA}.
#              Tags :current → :previous, :sha → :current, restarts container.
# `rollback` — runs flights-web:previous in place of :current, repoints :current.
#
# Env:
#   GITHUB_SHA          (required for swap)
#   FLIGHTS_WEB_PORT    (default 3002 — host port that nginx proxies to)
#   IMAGE_NAME          (default flights-web — set this to point at a registry later)
set -euo pipefail

DRY_RUN=0
if [ "${1:-}" = "--dry-run" ]; then
  DRY_RUN=1
  shift
fi

CMD="${1:-}"
PORT="${FLIGHTS_WEB_PORT:-3002}"
IMAGE="${IMAGE_NAME:-flights-web}"

run() {
  if [ "$DRY_RUN" -eq 1 ]; then
    printf 'docker %s\n' "$*"
  else
    docker "$@"
  fi
}

run_or_skip() {
  # Same as run, but doesn't fail in real mode if the docker call fails.
  if [ "$DRY_RUN" -eq 1 ]; then
    printf 'docker %s\n' "$*"
  else
    docker "$@" || true
  fi
}

case "$CMD" in
  swap)
    : "${GITHUB_SHA:?GITHUB_SHA required for swap}"
    SHORT_SHA="${GITHUB_SHA:0:7}"
    # 1. Tag the currently-live image as :previous (skip if first deploy).
    if [ "$DRY_RUN" -eq 1 ] || docker image inspect "${IMAGE}:current" >/dev/null 2>&1; then
      run tag "${IMAGE}:current" "${IMAGE}:previous"
    fi
    # 2. Tag the new SHA as :current.
    run tag "${IMAGE}:${SHORT_SHA}" "${IMAGE}:current"
    # 3. Stop + remove existing container if present.
    run_or_skip stop flights-web
    run_or_skip rm flights-web
    # 4. Run new container.
    run run -d --name flights-web --restart unless-stopped \
      -p "127.0.0.1:${PORT}:8080" \
      "${IMAGE}:current"
    # 5. Wait for the SSR inside the container to start listening before
    #    returning. Without this, the next nginx-side probe gets a few
    #    502s while Node.js is still booting — works (wait-for-url.sh
    #    retries) but adds noise to the deploy log.
    if [ "$DRY_RUN" -eq 0 ]; then
      attempt=1
      while [ "$attempt" -le 30 ]; do
        if curl -fsS -o /dev/null "http://127.0.0.1:${PORT}/"; then
          echo "swap: SSR ready on :${PORT} after $attempt attempt(s)"
          break
        fi
        if [ "$attempt" -eq 30 ]; then
          echo "swap: SSR did not respond on :${PORT} after 30 attempts" >&2
          exit 1
        fi
        sleep 1
        attempt=$((attempt + 1))
      done
    fi
    ;;
  rollback)
    if [ "$DRY_RUN" -eq 0 ] && ! docker image inspect "${IMAGE}:previous" >/dev/null 2>&1; then
      echo "fatal: ${IMAGE}:previous not found — cannot rollback" >&2
      exit 1
    fi
    run_or_skip stop flights-web
    run_or_skip rm flights-web
    run run -d --name flights-web --restart unless-stopped \
      -p "127.0.0.1:${PORT}:8080" \
      "${IMAGE}:previous"
    # Repoint :current to :previous so subsequent swaps have a sane baseline.
    run tag "${IMAGE}:previous" "${IMAGE}:current"
    ;;
  *)
    echo "usage: $0 [--dry-run] <swap|rollback>" >&2
    exit 2
    ;;
esac