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

WORK_DIR=""
while [[ $# -gt 0 ]]; do
  case "$1" in
    --work-dir)
      WORK_DIR="${2:-}"
      shift 2
      ;;
    *)
      echo "[ERROR] unsupported argument: $1" >&2
      exit 1
      ;;
  esac
done

if [[ -z "${WORK_DIR}" ]]; then
  echo "[ERROR] --work-dir is required" >&2
  exit 1
fi

PAYLOAD_DIR="${WORK_DIR}/payload"
STATUS_FILE="${WORK_DIR}/status.json"
LOG_FILE="${WORK_DIR}/restore.log"
MANIFEST="${PAYLOAD_DIR}/payload-manifest.json"
# Java 解包阶段会把 payload-manifest.json 转换成下面三份 TSV。
# shell 阶段只消费 TSV，避免在 bash 中解析复杂 JSON。
FILES_PLAN="${WORK_DIR}/restore-files.tsv"
DATABASES_PLAN="${WORK_DIR}/restore-databases.tsv"
MQ_PLAN="${WORK_DIR}/restore-mq.tsv"
ENV_FILE="${WORK_DIR}/restore-env.sh"
STOP_COMMANDS_PLAN="${WORK_DIR}/restore-stop-commands.tsv"
START_COMMANDS_PLAN="${WORK_DIR}/restore-start-commands.tsv"

json_escape() {
  local value="$1"
  value="${value//\\/\\\\}"
  value="${value//\"/\\\"}"
  value="${value//$'\n'/ }"
  printf '%s' "${value}"
}

write_status() {
  local status="$1"
  local phase="$2"
  local message="$3"
  # status.json 是 Java 查询接口和运维排障共同读取的轻量状态文件。
  # 即使 TMS 服务被 stop，脚本仍会持续刷新这个文件，服务重启后可继续展示结果。
  printf '{"status":"%s","phase":"%s","message":"%s","updatedAt":"%s"}\n' \
    "$(json_escape "${status}")" \
    "$(json_escape "${phase}")" \
    "$(json_escape "${message}")" \
    "$(date '+%Y-%m-%dT%H:%M:%S%z')" > "${STATUS_FILE}"
}

log() {
  printf '[%s] %s\n' "$(date '+%F %T')" "$1" >> "${LOG_FILE}"
}

fail() {
  local message="$1"
  local phase="${2:-FAILED}"
  log "[ERROR] ${message}"
  write_status "FAILED" "${phase}" "${message}"
  exit 1
}

require_env() {
  local name="$1"
  local value="${!name:-}"
  if [[ -z "${value}" ]]; then
    fail "required environment variable ${name} is empty" "${2:-PRECHECK}"
  fi
}

restore_files() {
  [[ -f "${FILES_PLAN}" ]] || return 0
  # restore-files.tsv 每行格式：payload内相对路径<TAB>目标绝对路径。
  # 目标路径白名单已在 Java 解包阶段校验，这里只负责按计划覆盖文件。
  while IFS=$'\t' read -r entry_path restore_path || [[ -n "${entry_path:-}" ]]; do
    [[ -n "${entry_path:-}" ]] || continue
    [[ -n "${restore_path:-}" ]] || fail "restore file target is empty for ${entry_path}" "FILE"
    local source_file="${PAYLOAD_DIR}/${entry_path}"
    [[ -f "${source_file}" ]] || fail "restore source file not found: ${entry_path}" "FILE"
    mkdir -p "$(dirname "${restore_path}")"
    cp -f "${source_file}" "${restore_path}"
    log "restored file: ${restore_path}"
  done < "${FILES_PLAN}"
}

restore_databases() {
  [[ -f "${DATABASES_PLAN}" ]] || return 0
  [[ -s "${DATABASES_PLAN}" ]] || return 0
  local script="${DB_RESTORE_SCRIPT_PATH:-}"
  [[ -n "${script}" && -x "${script}" ]] || fail "DB_RESTORE_SCRIPT_PATH is not executable" "DATABASE"
  # 数据库连接参数来自 Java 生成的 restore-env.sh；实际导入命令下沉到 restore-db.sh，
  # 方便现场根据 MySQL/TiDB 客户端和账号策略调整实现。
  require_env "DB_HOST" "DATABASE"
  require_env "DB_PORT" "DATABASE"
  require_env "DB_USER" "DATABASE"
  local mysql_path="${MYSQL_PATH:-mysql}"
  local db_password="${DB_PASSWORD:-}"
  while IFS=$'\t' read -r entry_path db_name || [[ -n "${entry_path:-}" ]]; do
    [[ -n "${entry_path:-}" ]] || continue
    [[ -n "${db_name:-}" ]] || fail "database name is empty for ${entry_path}" "DATABASE"
    local sql_file="${PAYLOAD_DIR}/${entry_path}"
    [[ -f "${sql_file}" ]] || fail "sql file not found: ${entry_path}" "DATABASE"
    "${script}" \
      --mysql-path "${mysql_path}" \
      --host "${DB_HOST}" \
      --port "${DB_PORT}" \
      --username "${DB_USER}" \
      --password "${db_password}" \
      --db-name "${db_name}" \
      --sql-file "${sql_file}" >> "${LOG_FILE}" 2>&1
    log "restored database: ${db_name}"
  done < "${DATABASES_PLAN}"
}

replay_mq() {
  [[ -f "${MQ_PLAN}" ]] || return 0
  [[ -s "${MQ_PLAN}" ]] || return 0
  local script="${MQ_REPLAY_SCRIPT_PATH:-}"
  [[ -n "${script}" && -x "${script}" ]] || fail "MQ_REPLAY_SCRIPT_PATH is not executable" "MQ_REPLAY"
  # MQ replay 当前只接收 Java 生成的上下文文件，具体恢复 RabbitMQ/TLQ/CFMQ 的命令由现场脚本实现。
  while IFS= read -r entry_path || [[ -n "${entry_path:-}" ]]; do
    [[ -n "${entry_path:-}" ]] || continue
    local context_file="${PAYLOAD_DIR}/${entry_path}"
    [[ -f "${context_file}" ]] || fail "mq replay context not found: ${entry_path}" "MQ_REPLAY"
    "${script}" --context-file "${context_file}" --work-dir "${WORK_DIR}" >> "${LOG_FILE}" 2>&1
    log "mq replay applied"
  done < "${MQ_PLAN}"
}

run_service_commands() {
  local plan_file="$1"
  local phase="$2"
  [[ -f "${plan_file}" ]] || return 1
  [[ -s "${plan_file}" ]] || return 1
  while IFS=$'\t' read -r code required command || [[ -n "${code:-}" ]]; do
    [[ -n "${code:-}" ]] || continue
    [[ -n "${command:-}" ]] || fail "service command is empty: ${code}" "${phase}"
    log "${phase} ${code}: ${command}"
    if bash -lc "${command}" >> "${LOG_FILE}" 2>&1; then
      log "${phase} ${code}: success"
    elif [[ "${required}" == "true" ]]; then
      fail "${phase} command failed: ${code}" "${phase}"
    else
      log "[WARN] ${phase} ${code}: failed but ignored"
    fi
  done < "${plan_file}"
  return 0
}

health_check() {
  local url="${HEALTH_CHECK_URL:-}"
  [[ -n "${url}" ]] || {
    log "health check skipped: HEALTH_CHECK_URL is empty"
    return 0
  }
  command -v curl >/dev/null 2>&1 || fail "curl command not found for health check" "HEALTH_CHECK"
  local timeout="${HEALTH_CHECK_TIMEOUT_SECONDS:-5}"
  local response
  response="$(curl -fsS --max-time "${timeout}" "${url}")" || fail "health check request failed" "HEALTH_CHECK"
  if [[ "${response}" != *"UP"* ]]; then
    fail "health check did not return UP" "HEALTH_CHECK"
  fi
  log "health check passed"
}

mkdir -p "${WORK_DIR}"
touch "${LOG_FILE}"
chmod 700 "${WORK_DIR}" || true

if [[ -f "${ENV_FILE}" ]]; then
  # shellcheck disable=SC1090
  # restore-env.sh 由 LightweightRestoreApplierLauncher 生成，包含脚本路径、数据库连接和健康检查配置。
  source "${ENV_FILE}"
fi

[[ -f "${MANIFEST}" ]] || fail "payload manifest not found" "PRECHECK"

delay_seconds="${RESTORE_APPLY_DELAY_SECONDS:-3}"
if [[ "${delay_seconds}" =~ ^[0-9]+$ ]] && [[ "${delay_seconds}" -gt 0 ]]; then
  write_status "RUNNING" "APPLY_DELAY" "restore apply will start"
  log "APPLY_DELAY ${delay_seconds}s"
  sleep "${delay_seconds}"
fi

# 从这里开始进入停机恢复窗口。TMS_SCRIPT_PATH stop/start 允许失败后继续，
# 因为某些部署环境可能由 systemd/外部平台接管服务状态，但文件/数据库/MQ 失败必须中断。
write_status "RUNNING" "SERVICE_STOP" "stopping services"
log "SERVICE_STOP"
if ! run_service_commands "${STOP_COMMANDS_PLAN}" "SERVICE_STOP" \
    && [[ -n "${TMS_SCRIPT_PATH:-}" && -x "${TMS_SCRIPT_PATH}" ]]; then
  "${TMS_SCRIPT_PATH}" stop >> "${LOG_FILE}" 2>&1 || true
fi

write_status "RUNNING" "FILE" "restoring files"
log "FILE"
restore_files

write_status "RUNNING" "DATABASE" "restoring databases"
log "DATABASE"
restore_databases

write_status "RUNNING" "MQ_REPLAY" "replaying mq configuration"
log "MQ_REPLAY"
replay_mq

write_status "RUNNING" "SERVICE_START" "starting services"
log "SERVICE_START"
if ! run_service_commands "${START_COMMANDS_PLAN}" "SERVICE_START" \
    && [[ -n "${TMS_SCRIPT_PATH:-}" && -x "${TMS_SCRIPT_PATH}" ]]; then
  "${TMS_SCRIPT_PATH}" start >> "${LOG_FILE}" 2>&1 || true
fi

write_status "RUNNING" "HEALTH_CHECK" "checking health"
log "HEALTH_CHECK"
health_check

write_status "SUCCESS" "DONE" "restore applied"
log "DONE"