#!/usr/bin/env bash
# Re-deploys the last tag that passed a health check, or an explicit tag:
#
#   /home/deploy/websites/ksan.dev/rollback.sh            # last known good
#   /home/deploy/websites/ksan.dev/rollback.sh <sha>      # a specific build
#
# The image is already on the host, so this is a container restart, not a build.
set -euo pipefail

SITE_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SITE_DIR"

if [[ $# -ge 1 ]]; then
  IMAGE_TAG="$1"
elif [[ -f .tag.good ]]; then
  IMAGE_TAG="$(cat .tag.good)"
else
  echo "rollback: no .tag.good and no tag given — nothing to roll back to" >&2
  exit 1
fi

if [[ ! "$IMAGE_TAG" =~ ^[0-9a-f]{7,40}$ ]]; then
  echo "rollback: invalid tag '$IMAGE_TAG'" >&2
  exit 1
fi
export IMAGE_TAG

echo "rollback: restoring $IMAGE_TAG"
docker compose pull --quiet
docker compose up -d --remove-orphans --wait --wait-timeout 120
echo "rollback: $IMAGE_TAG is live"