#!/usr/bin/env bash
# Put an earlier deploy back: build the code of a deploy-N tag in a temporary copy and deploy it with scripts/deploy.sh.
#   scripts/rollback.sh deploy-3              server + agent + runner of that tag (default: all)
#   scripts/rollback.sh deploy-3 server       only the server
#   git tag -n9 -l 'deploy-*'                 list the deploys with their details
#
# It uses the CURRENT deploy.sh (hash checks included) but the OLD source, and makes no new tag.
# Notes: everybody is logged out once (the server restarts). Agents on machines are not changed: update them from the
# Models page when nothing is downloading. If a newer version changed the format of a file the server keeps in
# /opt/wxch (config.json, keys.json), check that the old version can read it. The VPS also keeps the server that was
# running before the last switch as /opt/wxch/wxch-server.prev.
set -euo pipefail
cd "$(dirname "$0")/.."
TAG="${1:?usage: scripts/rollback.sh deploy-N [server|agent|runner|all]}"; shift
git rev-parse -q --verify "refs/tags/$TAG^{commit}" >/dev/null || { echo "no such tag: $TAG (see: git tag -n9 -l 'deploy-*')" >&2; exit 1; }
[ $# -gt 0 ] || set -- all

echo "rolling back to $TAG:"; git tag -n9 -l "$TAG" | head -3
TMP="$(mktemp -d)"
trap 'git worktree remove --force "$TMP/src" >/dev/null 2>&1 || true; rm -rf "$TMP"' EXIT
git worktree add --detach "$TMP/src" "$TAG" >/dev/null
bash scripts/deploy.sh --src "$TMP/src" "$@"
echo "rolled back to $TAG. The next deploy from the latest code will get a new number."