import { sys } from "cc";
import { WxCloudApi } from "../wx_clound_client_api/WxCloudApi";
import { mLogger } from "./Logger";
import { smc, GameDate, CloudData } from "./SingletonModuleComp";

export class GameDataSync {
    private debugMode: boolean = false;
    private _localDataDirty: boolean = false;
    private _lastSyncTime: number = 0;
    private _syncTimerId: any = null;
    private readonly LOCAL_STORAGE_KEY = "Heros_GameData_Local";

    /** 标记数据为脏，并更新时间戳，然后保存到本地 */
    public markDataDirty() {
        this._localDataDirty = true;
        this.saveToLocal();
        // 尝试触发异步同步
        this.tryAsyncCloudSync();
    }

    /** 同步数据到本地 localStorage */
    private saveToLocal() {
        try {
            const data = smc.getGameDate();
            data.timestamp = Date.now(); // 更新时间戳
            sys.localStorage.setItem(this.LOCAL_STORAGE_KEY, JSON.stringify(data));
        } catch (error) {
            mLogger.error(this.debugMode, 'GameDataSync', '保存本地数据失败:', error);
        }
    }

    /** 从本地 localStorage 读取数据 */
    private loadFromLocal(): GameDate | null {
        try {
            const str = sys.localStorage.getItem(this.LOCAL_STORAGE_KEY);
            if (str) {
                return JSON.parse(str) as GameDate;
            }
        } catch (error) {
            mLogger.error(this.debugMode, 'GameDataSync', '读取本地数据失败:', error);
        }
        return null;
    }

    /**
     * 判断是否为微信客户端
     */
    public isWxClient(): boolean {
        return sys.platform === sys.Platform.WECHAT_GAME;
    }

    public updateCloudData() { 
        this.markDataDirty();
        return true;
    }

    /** 尝试异步同步云端数据，带有防抖（Debounce）保护 */
    private tryAsyncCloudSync() {
        if (!this.isWxClient()) return;
        
        // 如果当前有同步在等待，清除之前的定时器
        if (this._syncTimerId !== null) {
            clearTimeout(this._syncTimerId);
        }

        // 防抖：延迟 3 秒同步，期间多次操作合并为一次同步请求
        this._syncTimerId = setTimeout(() => {
            this._syncTimerId = null;
            this.executeCloudSync();
        }, 3000);
    }

    /** 实际执行云端同步 */
    private executeCloudSync() {
        if (!this._localDataDirty) return;

        let gameData = smc.getGameDate();
        // 保证云端存一份时间戳，供下次登录对比
        gameData.timestamp = Date.now(); 

        WxCloudApi.save(gameData).then((result) => {
            if (result.result.code === 200) {
                mLogger.log(this.debugMode, 'GameDataSync', "静默云端保存成功", result.result);
                // 同步成功，清除脏标记
                this._localDataDirty = false;
                this._lastSyncTime = Date.now();
            } else {
                mLogger.warn(this.debugMode, 'GameDataSync', `[GameDataSync]: 静默同步失败(等待下次重试): ${result.result.msg}`);
                // 失败了不清除脏标记，下次有变化或定时器检查时会再次重试
            }
        }).catch((error) => {
            mLogger.error(this.debugMode, 'GameDataSync', `[GameDataSync]: 静默同步异常(等待下次重试):`, error);
        });
    }

    /**
     * 登录阶段与云端双向同步数据（sync 模式）。
     * 时间戳对比在云端完成：
     * - 本地较新：云端已被本地数据覆盖，无需额外处理
     * - 云端较新：用云端数据覆盖本地，并写入 localStorage
     * @returns true=本次以云端数据为准覆盖了本地；false=以本地数据为准或同步失败
     */
    public async syncFromCloud(): Promise<boolean> {
        const localData = this.loadFromLocal();

        // 非微信客户端：仅使用本地缓存
        if (!this.isWxClient()) {
            if (localData) {
                smc.overrideLocalDataWithRemote({ data: localData });
            }
            return false;
        }

        try {
            // 本地无缓存时用空对象参与对比，云端会直接下发
            const gameData = localData || ({} as GameDate);
            gameData.timestamp = gameData.timestamp || 0;

            const result = await WxCloudApi.sync(gameData);
            const response = result.result;

            if (response && response.code === 200 && response.data) {
                const cloudData: CloudData = {
                    openid: response.data.openid || '',
                    data: (response.data.game_data || {}) as GameDate,
                };

                if (response.updated) {
                    // 本地数据较新，云端已被覆盖
                    mLogger.log(this.debugMode, 'GameDataSync', `[GameDataSync]: 本地数据较新，已覆盖云端。`);
                    if (localData) {
                        smc.overrideLocalDataWithRemote({ data: localData });
                    }
                    return false;
                } else {
                    // 云端数据较新，覆盖本地
                    mLogger.log(this.debugMode, 'GameDataSync', `[GameDataSync]: 云端数据较新，覆盖本地。`);
                    smc.overrideLocalDataWithRemote(cloudData);
                    this.saveToLocal();
                    return true;
                }
            }

            mLogger.warn(this.debugMode, 'GameDataSync', `[GameDataSync]: 云端同步失败，使用本地缓存兜底。`, response?.msg);
            if (localData) {
                smc.overrideLocalDataWithRemote({ data: localData });
            }
            return false;
        } catch (error) {
            mLogger.error(this.debugMode, 'GameDataSync', `[GameDataSync]: 云端同步异常，使用本地缓存兜底。`, error);
            if (localData) {
                smc.overrideLocalDataWithRemote({ data: localData });
            }
            return false;
        }
    }
}

export const gameDataSync = new GameDataSync();