/**
 * Activity Store — visionA Cloud（Dashboard 時間軸用）
 *
 * 對齊：
 *   - `.autoflow/03-design/components.md` §4 Dashboard `ActivityTimeline`
 *   - `.autoflow/03-design/flows/flow-offline-handling.md` §9 Activity Timeline 擴充
 *
 * 職責：
 *   - 保存最近的活動事件（配對、裝置上下線、燒錄、模型上傳等）
 *   - 容量上限 100 筆（超過從頭 drop）
 *
 * F6 範圍（雛形）：
 *   - 事件來源尚未接（F7/F8 會從 WS `/ws/devices/events` 推入 + login / upload 事件 seed）
 *   - 這個 store 先建立，讓 Dashboard 能 render empty state；真實事件由 F7+ 補
 */

"use client";

import { create } from "zustand";

/** 活動類型（對齊 flow-offline-handling.md §9 雲端版 + local-tool 既有類型） */
export type ActivityType =
  | "device_paired"
  | "device_unpaired"
  | "device_online"
  | "device_offline"
  | "tunnel_reconnected"
  | "flash_start"
  | "flash_complete"
  | "flash_error"
  | "model_upload"
  | "model_delete"
  | "cluster_degraded";

export interface ActivityEntry {
  id: string;
  type: ActivityType;
  message: string;
  /** Unix ms（用 `Date.now()`；方便前端相對時間格式化） */
  timestamp: number;
  /** 可選關聯 */
  deviceId?: string;
  modelId?: string;
}

const ACTIVITY_LIMIT = 100;

interface ActivityState {
  activities: ActivityEntry[];
  addActivity: (entry: Omit<ActivityEntry, "id" | "timestamp"> & {
    id?: string;
    timestamp?: number;
  }) => void;
  clear: () => void;
}

export const useActivityStore = create<ActivityState>()((set) => ({
  activities: [],

  addActivity: (entry) =>
    set((state) => {
      const id = entry.id ?? `act_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`;
      const timestamp = entry.timestamp ?? Date.now();
      const next: ActivityEntry = {
        id,
        type: entry.type,
        message: entry.message,
        timestamp,
        deviceId: entry.deviceId,
        modelId: entry.modelId,
      };
      // 新事件放最前面，超過上限從尾部 drop
      const combined = [next, ...state.activities].slice(0, ACTIVITY_LIMIT);
      return { activities: combined };
    }),

  clear: () => set({ activities: [] }),
}));