/**
 * OmniCard AI (CRMmp) - 移动端弱网离线视觉指示器与断网重放队列
 * 严格遵循 AGENTS.md 规范与 uts 强类型规范，一套代码兼顾 App 与 Web/H5
 */

export interface OfflineAction {
  id?: string;
  type: string;
  url: string;
  method?: 'GET' | 'POST' | 'PUT' | 'DELETE';
  data?: any;
  header?: Record<string, any>;
  timestamp?: number;
  retryCount?: number;
}

export interface OfflineQueueStatus {
  isOnline: boolean;
  networkType: string;
  pendingCount: number;
  lastSyncTime?: number;
}

export interface ReplayResult {
  total: number;
  success: number;
  failed: number;
}

const STORAGE_KEY = 'omni_offline_queue';
const DEFAULT_MAX_RETRIES = 3;

let onlineState = true;
let currentNetworkType = 'wifi';
let lastSyncTimestamp: number | undefined = undefined;

/**
 * 获取当前网络在线状态
 */
export function isOnline(): boolean {
  return onlineState;
}

/**
 * 手动或通过原生事件更新网络状态
 */
export function setNetworkStatus(online: boolean, networkType = 'unknown'): void {
  onlineState = online;
  currentNetworkType = networkType;
}

/**
 * 获取离线队列所有条目
 */
export function getOfflineQueue(): OfflineAction[] {
  try {
    const raw = uni.getStorageSync(STORAGE_KEY);
    if (!raw) return [];
    const list = JSON.parse(String(raw));
    return Array.isArray(list) ? list : [];
  } catch (e) {
    return [];
  }
}

/**
 * 清空离线队列
 */
export function clearOfflineQueue(): void {
  try {
    uni.removeStorageSync(STORAGE_KEY);
  } catch (e) {}
}

/**
 * 暂存一个离线操作到本地队列 (FIFO)
 */
export function enqueueOfflineAction(action: OfflineAction): number {
  const queue = getOfflineQueue();
  const item: OfflineAction = {
    ...action,
    id: action.id || `offline_${Date.now()}_${Math.random().toString(36).slice(2, 7)}`,
    timestamp: action.timestamp || Date.now(),
    retryCount: action.retryCount || 0,
  };

  queue.push(item);
  try {
    uni.setStorageSync(STORAGE_KEY, JSON.stringify(queue));
  } catch (e) {}

  return queue.length;
}

/**
 * 网络恢复时自动重放离线队列
 */
export async function replayOfflineQueue(
  executor: (action: OfflineAction) => Promise<boolean>,
  maxRetries = DEFAULT_MAX_RETRIES
): Promise<ReplayResult> {
  const queue = getOfflineQueue();
  if (queue.length === 0) {
    return { total: 0, success: 0, failed: 0 };
  }

  const remaining: OfflineAction[] = [];
  let successCount = 0;
  let failedCount = 0;

  for (const item of queue) {
    let ok = false;
    try {
      ok = await executor(item);
    } catch (e) {
      ok = false;
    }

    if (ok) {
      successCount++;
    } else {
      failedCount++;
      const nextRetries = (item.retryCount || 0) + 1;
      if (nextRetries < maxRetries) {
        remaining.push({
          ...item,
          retryCount: nextRetries,
        });
      }
    }
  }

  try {
    if (remaining.length > 0) {
      uni.setStorageSync(STORAGE_KEY, JSON.stringify(remaining));
    } else {
      uni.removeStorageSync(STORAGE_KEY);
    }
  } catch (e) {}

  lastSyncTimestamp = Date.now();
  return {
    total: queue.length,
    success: successCount,
    failed: failedCount,
  };
}

/**
 * 获取离线队列综合状态
 */
export function getOfflineQueueStatus(): OfflineQueueStatus {
  const queue = getOfflineQueue();
  return {
    isOnline: onlineState,
    networkType: currentNetworkType,
    pendingCount: queue.length,
    lastSyncTime: lastSyncTimestamp,
  };
}

/**
 * 格式化多语言横幅提示文案
 */
export function formatOfflineBannerText(lang: string = 'en', pendingCount = 0): string {
  const normalized = (lang || 'en').toLowerCase().split('-')[0];
  switch (normalized) {
    case 'zh':
      return pendingCount > 0
        ? `网络已断开 (${pendingCount} 条暂存待同步)`
        : '网络已断开，正在尝试重连...';
    case 'ar':
      return pendingCount > 0
        ? `غير متصل بالشبكة (${pendingCount} في الانتظار)`
        : 'غير متصل بالشبكة، جاري إعادة الاتصال...';
    case 'es':
      return pendingCount > 0
        ? `Sin conexión (${pendingCount} pendientes)`
        : 'Sin conexión, reintentando...';
    case 'fr':
      return pendingCount > 0
        ? `Hors ligne (${pendingCount} en attente)`
        : 'Hors ligne, reconnexion en cours...';
    case 'ja':
      return pendingCount > 0
        ? `オフライン (${pendingCount} 件の未送信保留)`
        : 'オフラインです。再接続中...';
    case 'en':
    default:
      return pendingCount > 0
        ? `Offline mode (${pendingCount} pending)`
        : 'Offline, reconnecting...';
  }
}