#!/usr/bin/env bash
# Rolls back to the previously deployed image tag, per infra/docker/IMAGE_STRATEGY.md —
# "rollback is changing one variable and re-running the Ansible role." Reads
# /opt/rootnode/deploy-history.log (written by deploy-production.sh) for the tag before the
# current one; pass an explicit tag instead if you need to go back further than one step.
#
# Usage: ./rollback-production.sh [explicit-image-tag]
set -euo pipefail
cd "$(dirname "$0")/../ansible"

DEPLOY_LOG="/opt/rootnode/deploy-history.log"

if [ -n "${1:-}" ]; then
  TARGET_TAG="$1"
else
  [ -f "$DEPLOY_LOG" ] || { echo "No $DEPLOY_LOG found and no explicit tag given — nothing to roll back to." >&2; exit 1; }
  LINES=$(wc -l < "$DEPLOY_LOG")
  [ "$LINES" -ge 2 ] || { echo "Deploy history has fewer than 2 entries — nothing to roll back to. Pass an explicit tag instead." >&2; exit 1; }
  TARGET_TAG=$(tail -2 "$DEPLOY_LOG" | head -1 | awk '{print $2}')
fi

echo "Rolling back production to image_tag=$TARGET_TAG"
read -r -p "Type ROLLBACK to continue: " CONFIRM
[ "$CONFIRM" = "ROLLBACK" ] || { echo "Aborted."; exit 1; }

ansible-playbook site.yml -i inventory/production.ini \
  -e "image_tag=$TARGET_TAG" \
  --vault-password-file .vault_pass

echo "$(date -u +%Y-%m-%dT%H:%M:%SZ) $TARGET_TAG (rollback)" >> "$DEPLOY_LOG"
echo "==> Rolled back to $TARGET_TAG. Verify with infra/scripts/production-smoke-test.sh."
echo "NOTE: this rolls back the application images only. If the rollback needs to undo a"
echo "database migration too, see docs/RUNBOOK_FAILED_MIGRATION.md — schema changes are not"
echo "automatically reversible by this script."