#!/usr/bin/env bash
#
# Go back to the previous release.
#
#   ./deploy/rollback.sh           → the release before the current one
#   ./deploy/rollback.sh <name>    → a specific release
#   ./deploy/rollback.sh --list    → what is available
#
# Rolling back is flipping a symlink, so it takes about as long as it takes
# ssh to connect. Nothing is rebuilt and nothing is deleted.

set -euo pipefail

SERVER="${ERATIC_SERVER:-root@178.104.116.235}"
SSH_KEY="${ERATIC_SSH_KEY:-$HOME/.ssh/id_ed25519_eratic}"
REMOTE_ROOT="${ERATIC_REMOTE_ROOT:-/opt/web}"
PROJECT="${ERATIC_PROJECT:-eratic}"
SITE_ROOT="$REMOTE_ROOT/sites/$PROJECT"

remote() { ssh -o BatchMode=yes -o ConnectTimeout=15 -i "$SSH_KEY" "$SERVER" "$@"; }
ok() { printf '\033[32m✓\033[0m %s\n' "$*"; }
fail() { printf '\033[31m✗ %s\033[0m\n' "$*" >&2; exit 1; }

CURRENT="$(remote "readlink '$SITE_ROOT/current' 2>/dev/null | sed 's#releases/##' || true")"

if [[ "${1:-}" == "--list" ]]; then
	echo "Releases (newest first), current marked:"
	remote "ls -1t '$SITE_ROOT/releases'" | while read -r rel; do
		if [[ "$rel" == "$CURRENT" ]]; then
			printf '  \033[1m%s\033[0m  ← current\n' "$rel"
		else
			printf '  %s\n' "$rel"
		fi
	done
	exit 0
fi

TARGET="${1:-}"

if [[ -z "$TARGET" ]]; then
	# The newest release that is not the one currently live.
	TARGET="$(remote "ls -1t '$SITE_ROOT/releases'" | grep -v "^${CURRENT}\$" | head -1)"
	[[ -n "$TARGET" ]] || fail "no earlier release to roll back to"
fi

remote "test -d '$SITE_ROOT/releases/$TARGET'" \
	|| fail "release '$TARGET' does not exist — try --list"

echo "current:  ${CURRENT:-none}"
echo "rollback: $TARGET"

remote "cd '$SITE_ROOT' && ln -sfn 'releases/$TARGET' current.tmp && mv -Tf current.tmp current"
ok "current → releases/$TARGET"

for host in eratic.ro blog.eratic.ro fav.eratic.ro io.eratic.ro; do
	code="$(curl -sS -o /dev/null -w '%{http_code}' --max-time 20 "https://$host/" || echo 000)"
	printf '  https://%-16s → %s\n' "$host" "$code"
done