#!/bin/sh
# 回滚：VM 侧运行，把主机恢复到最近一份代码备份包并重启验证。
#
# 用法：deploy/rollback.sh <host> [user]
#   host：主机 IP 或域名（必填）；user：SSH 用户（默认 root）。
#
# 密码：与 deploy.sh 同款规则——绝不接受密码参数、不读 env 文件、
# 不打印任何密钥；SSH 密码由交互提示或调用方通道提供；需要代理时
# 用环境变量 SSH_PROXY_CMD 传入 ProxyCommand，未设则直连。
#
# 回滚边界：只回代码，不回数据库（理由见 deploy.sh 头注释与
# deploy/README.md：数据库迁移是只加列的幂等操作，老代码仍能读新列）。
# 备份包来自 deploy.sh 每次部署前在主机上打的
# /opt/codex-app-server-backups/codex-app-server-<时间戳>.tar.gz，
# 本脚本恢复其中最新的一份；主机上没有备份包时直接报错退出，不编造。
set -eu

HOST=${1:-}
USER_ARG=${2:-root}
if [ -z "$HOST" ]; then
  echo "用法：deploy/rollback.sh <host> [user]" >&2
  exit 2
fi

ssh_cmd() {
  if [ -n "${SSH_PROXY_CMD:-}" ]; then
    ssh -o "ProxyCommand $SSH_PROXY_CMD" -o StrictHostKeyChecking=no \
      -o UserKnownHostsFile=/dev/null "$@"
  else
    ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null "$@"
  fi
}

ssh_cmd "$USER_ARG@$HOST" 'sh -s' <<'HOST_SCRIPT'
set -eu
APP_DIR=/opt/codex-app-server
BACKUP_DIR=/opt/codex-app-server-backups

check_health() {
  OUT=$(curl -s --max-time 5 http://127.0.0.1:8765/health || true)
  [ -n "$OUT" ] && printf '%s' "$OUT" | python3 -c '
import json, sys
try:
    d = json.load(sys.stdin)
except Exception:
    sys.exit(1)
sys.exit(0 if (d.get("ok") is True and d.get("backend") == "postgres"
                and d.get("db_ok") is True) else 1)
'
}

wait_health() {
  i=0
  while [ "$i" -lt 12 ]; do
    if check_health; then return 0; fi
    sleep 5
    i=$((i + 1))
  done
  return 1
}

BACKUP_FILE=$(ls -t "$BACKUP_DIR"/codex-app-server-*.tar.gz 2>/dev/null \
  | head -n 1 || true)
if [ -z "$BACKUP_FILE" ]; then
  echo "主机上没有代码备份包，无法回滚：$BACKUP_DIR" >&2
  exit 1
fi
echo "将恢复备份包：$BACKUP_FILE"
systemctl stop codex-cloud-worker codex-cloud-server || true
find "$APP_DIR" -mindepth 1 -maxdepth 1 ! -name work -exec rm -rf {} +
tar -xzf "$BACKUP_FILE" -C /opt
chown -R codexsvc:codexsvc "$APP_DIR"
systemctl start codex-cloud-server codex-cloud-worker
if wait_health; then
  echo "回滚成功，health 通过，当前代码为备份包：$BACKUP_FILE"
  exit 0
fi
echo "回滚后 health 仍失败，需人工介入" >&2
exit 1
HOST_SCRIPT