#!/usr/bin/env bash
set -euo pipefail

# 环境变量：
# RESTORE_KEEP=1         # 恢复成功后也不删除文件
# RESTORE_CLEAN_ALL=1    # 无论成功失败都删除文件（危险）
# RESTORE_BASE=/path     # 自定义恢复目录，默认 $HOME/docker_migrate_restore

BLUE(){ echo -e "\033[1;34m$*\033[0m"; }
YEL(){  echo -e "\033[1;33m$*\033[0m"; }
RED(){  echo -e "\033[1;31m$*\033[0m"; }
OK(){   echo -e "\033[1;32m$*\033[0m"; }

asudo(){ if [[ $EUID -ne 0 ]]; then sudo "$@"; else "$@"; fi; }

pm_detect(){
  if command -v apt-get >/dev/null 2>&1; then echo apt; return; fi
  if command -v dnf     >/dev/null 2>&1; then echo dnf; return; fi
  if command -v yum     >/dev/null 2>&1; then echo yum; return; fi
  if command -v zypper  >/dev/null 2>&1; then echo zypper; return; fi
  if command -v apk     >/dev/null 2>&1; then echo apk; return; fi
  echo none
}

pm_install(){
  local pm="$1"; shift
  case "$pm" in
    apt)
      asudo apt-get update -y
      asudo env DEBIAN_FRONTEND=noninteractive apt-get install -y "$@"
      ;;
    dnf)    asudo dnf install -y "$@" ;;
    yum)    asudo yum install -y "$@" ;;
    zypper) asudo zypper --non-interactive install -y "$@" ;;
    apk)    asudo apk add --no-cache "$@" ;;
    *)      return 1 ;;
  esac
}

ensure_deps(){
  local PM; PM="$(pm_detect)"

  for pair in "curl curl" "tar tar" "jq jq" "docker docker"; do
    local bin="${pair%% *}" pkg="${pair##* }"
    if ! command -v "$bin" >/dev/null 2>&1; then
      if [[ "$PM" == "none" ]]; then
        RED "[ERR] 缺少命令：$bin，请手动在新服务器安装该命令后重试。"
        exit 1
      fi

      if [[ "$bin" == "docker" ]]; then
        YEL "[INFO] 安装依赖：$bin（以及 docker compose）"
        case "$PM" in
          apt)
            # Ubuntu/Debian 上通常是 docker.io 包
            pm_install "$PM" docker.io
            ;;
          dnf|yum|zypper|apk)
            # 多数发行版上包名为 docker
            pm_install "$PM" docker
            ;;
          *)
            pm_install "$PM" docker || true
            ;;
        esac

        # 尝试安装 docker compose（优先新版 docker compose 插件，其次 docker-compose）
        if ! docker compose version >/dev/null 2>&1 && ! command -v docker-compose >/dev/null 2>&1; then
          case "$PM" in
            apt)
              pm_install "$PM" docker-compose-plugin || pm_install "$PM" docker-compose || true
              ;;
            dnf|yum|zypper|apk)
              pm_install "$PM" docker-compose || true
              ;;
            *)
              pm_install "$PM" docker-compose || true
              ;;
          esac
        fi
      else
        YEL "[INFO] 安装依赖：$bin"
        pm_install "$PM" "$pkg"
      fi
    fi
  done

  # 尝试启动 docker
  if ! docker info >/dev/null 2>&1; then
    YEL "[INFO] 尝试启动 Docker 服务..."
    if command -v systemctl >/dev/null 2>&1; then
      asudo systemctl enable --now docker || true
    fi
    if ! docker info >/dev/null 2>&1 && command -v service >/dev/null 2>&1; then
      asudo service docker start || true
    fi
    if ! docker info >/dev/null 2>&1; then
      RED "[ERR] Docker 未能启动，请确认在新服务器上正确安装并配置 Docker。"
      exit 1
    fi
  fi
}

prompt_url(){
  local u="${1:-}"
  if [[ -z "$u" ]]; then
    read -rp "请输入旧服务器“一键包下载链接”（以 .tar.gz 结尾）： " u
  fi
  if ! [[ "$u" =~ \.tar\.gz($|\?) ]]; then
    RED "[ERR] 链接必须以 .tar.gz 结尾。"
    exit 1
  fi
  echo "$u"
}

main(){
  ensure_deps

  local URL; URL="$(prompt_url "${1:-}")"
  local BASE="${RESTORE_BASE:-$HOME/docker_migrate_restore}"
  mkdir -p "$BASE"

  # 生成临时 ID/目录
  local RID
  RID="$(basename "$URL" | sed 's/\.tar\.gz.*$//' | tr -dc 'A-Za-z0-9_-')"
  [[ -n "$RID" ]] || RID="$(date +%s)"

  local TGZ="${BASE}/bundle.tar.gz"
  local OUTDIR="${BASE}/${RID}"

  BLUE "[INFO] 下载：$URL"
  if ! curl -fL --progress-bar "$URL" -o "$TGZ"; then
    RED "[ERR] 下载失败：$URL"
    exit 1
  fi
  OK "[OK] 保存路径：$TGZ"
  BLUE "[INFO] 文件大小：$(du -h "$TGZ" | awk '{print $1}')"

  BLUE "[INFO] 解压到：$OUTDIR"
  mkdir -p "$OUTDIR"
  BLUE "[INFO] 正在解压压缩包（根据文件大小可能需要一段时间，请不要中断）..."
  if ! tar -xzf "$TGZ" -C "$OUTDIR"; then
    RED "[ERR] 解压失败，请检查磁盘空间或确认文件是否完整。"
    exit 1
  fi

  # 进入真正的 bundle 目录（可能是 <RID>/RID 或 <RID>/）
  local BUNDLE_DIR=""
  if [[ -d "${OUTDIR}/${RID}" && -f "${OUTDIR}/${RID}/restore.sh" ]]; then
    BUNDLE_DIR="${OUTDIR}/${RID}"
  else
    # 兜底：找含 restore.sh 的第一层目录
    BUNDLE_DIR="$(find "$OUTDIR" -maxdepth 2 -type f -name restore.sh -printf '%h\n' | head -n1 || true)"
  fi

  if [[ -z "$BUNDLE_DIR" || ! -f "${BUNDLE_DIR}/restore.sh" ]]; then
    RED "[ERR] 未找到 restore.sh，解压内容异常：$OUTDIR"
    exit 1
  fi

  BLUE "[INFO] 执行恢复脚本：${BUNDLE_DIR}/restore.sh"
  BLUE "[INFO] 该步骤会加载镜像、回灌卷和绑定目录，并启动容器，可能需要数分钟，请耐心等待..."

  set +e
  bash "${BUNDLE_DIR}/restore.sh"
  local rc=$?
  set -e

  if [[ $rc -eq 0 ]]; then
    OK "[OK] 恢复完成！当前容器："
    docker ps --format "  {{.Names}}\t{{.Status}}\t{{.Ports}}"
    if [[ "${RESTORE_KEEP:-0}" == "1" ]]; then
      YEL "[INFO] 已按 RESTORE_KEEP=1 保留文件：$TGZ 与 $OUTDIR"
    else
      rm -rf "$TGZ" "$OUTDIR" 2>/dev/null || true
      OK "[OK] 已清理下载文件与临时目录"
    fi
    exit 0
  else
    RED "[ERR] 恢复脚本返回非零：$rc"
    YEL "[INFO] 为便于排查，默认保留文件：$TGZ 与 $OUTDIR"
    if [[ "${RESTORE_CLEAN_ALL:-0}" == "1" ]]; then
      YEL "[WARN] RESTORE_CLEAN_ALL=1：仍将强制删除文件"
      rm -rf "$TGZ" "$OUTDIR" 2>/dev/null || true
      OK "[OK] 已清理下载文件与临时目录"
    fi
    exit "$rc"
  fi
}

main "$@"