import { game, Game } from 'cc';
import { EDITOR } from 'cc/env';
import { GEvent } from '../../mx/module/event/GEvent';
import { BattleUiPauseGate } from '../battle/BattleUiPauseGate';
import { LoadScheduler } from '../../mx/module/res/LoadScheduler';
import { getResourcePhase, ResourcePhase } from '../../mx/module/res/ResourcePhase';
import { MemoryDowngrade } from './MemoryDowngrade';

/** 切后台暂停门闩 token（与 BattleUiPauseGate 一致） */
const BACKGROUND_PAUSE_TOKEN = 'app-background';

/**
 * 小游戏前后台生命周期：战斗暂停、预载降压、屏幕常亮。
 * 由 BootPipeline 安装；战斗进/退由 GameController 切换常亮意图。
 */
export class AppLifecycle {
    private static _installed = false;
    private static _inBackground = false;
    private static _battleKeepScreen = false;

    static install(): void {
        if (this._installed) return;
        this._installed = true;
        game.on(Game.EVENT_HIDE, this._onHide, this);
        game.on(Game.EVENT_SHOW, this._onShow, this);
        GEvent.Ins.on(GEvent.PLATFORM_SHOW, this._onPlatformShow, this);
    }

    /** 战斗进行中保持屏幕常亮；退战斗须显式关闭 */
    static setBattleKeepScreen(enabled: boolean): void {
        this._battleKeepScreen = enabled;
        if (!this._inBackground) {
            gg.sdk.setKeepScreenOn(enabled);
        }
    }

    /** 平台 onShow 回调：容器恢复后重设常亮（离开小游戏会失效） */
    static onPlatformShow(): void {
        if (this._battleKeepScreen && !this._inBackground) {
            gg.sdk.setKeepScreenOn(true);
        }
    }

    static isInBattle(): boolean {
        const battle = gg.game?.CurentBattle;
        if (battle && !battle.IsGameOver) return true;
        return getResourcePhase() === ResourcePhase.Battle;
    }

    private static _onPlatformShow(): void {
        this.onPlatformShow();
    }

    private static _onHide(): void {
        if (EDITOR) return;
        this._inBackground = true;
        if (this.isInBattle()) {
            BattleUiPauseGate.acquire(BACKGROUND_PAUSE_TOKEN);
        }
        LoadScheduler.getInstance().setSilentPaused(true);
        gg.sdk.pfTriggerGC();
    }

    private static _onShow(): void {
        if (EDITOR) return;
        this._inBackground = false;
        BattleUiPauseGate.release(BACKGROUND_PAUSE_TOKEN);
        this._syncSilentPreload();
        this.onPlatformShow();
    }

    /** 恢复 silent：仅内存降档暂停，战斗中允许局内补载 */
    private static _syncSilentPreload(): void {
        LoadScheduler.getInstance().setSilentPaused(MemoryDowngrade.level >= 1);
    }
}