import ServerEnvironment, { ServerTarget } from "./ServerEnvironment";
import ClientUpdate from "./ClientUpdate";
import Utils from "../Pay/Utils";
import DailyTaskProgressTracker from "../Task/DailyTaskProgressTracker";
import { MiniGameSdk } from "../../Sdk/MiniGameSdk";

declare const wx: any;

/** Home-only, full-process switch. Never changes the active transport or storage scope. */
export default class ServerSwitch {
    static inProgress = false;
    private static confirming = false;

    private static isBrowser(): boolean { return typeof wx === "undefined" && cc.sys.isBrowser; }
    private static modal(options: any): void {
        if (!this.isBrowser()) { wx.showModal(options); return; }
        try {
            const confirm = options.showCancel === false
                ? (window.alert(options.title + "\n" + options.content), true)
                : window.confirm(options.title + "\n" + options.content);
            if (options.success) options.success({ confirm });
        } finally { if (options.complete) options.complete(); }
    }
    private static showLoading(title: string): void {
        if (!this.isBrowser()) wx.showLoading({ title, mask: true });
    }
    private static restart(failed: () => void): void {
        if (!this.isBrowser()) { MiniGameSdk.API.reboot(undefined, failed); return; }
        try { window.location.reload(); } catch (_) { failed(); }
    }

    static choose(target: ServerTarget, refresh: () => void): void {
        if (!ServerEnvironment.canSwitch() || this.inProgress || this.confirming || ClientUpdate.blocked
            || cc.director.getScene()?.name !== "HomeScene") return;
        if (target === ServerEnvironment.current() && target === ServerEnvironment.next()) return;
        const cancelPending = target === ServerEnvironment.current();
        this.confirming = true;
        this.modal({
            title: cancelPending ? "取消服务器切换" : "切换服务器",
            content: cancelPending ? "取消待生效的切换，继续使用当前服务器？"
                : `将切换到${target === "test" ? "测试服" : "正式服"}并重启游戏，是否继续？`,
            confirmText: cancelPending ? "确认取消" : "重启切换",
            success: result => {
                if (!result.confirm) return;
                if (cancelPending) {
                    try { ServerEnvironment.saveNext(target); refresh(); }
                    catch (_) { this.modal({ title: "保存失败", content: "服务器选择保存失败，请重试", showCancel: false }); }
                } else {
                    this.perform(target, refresh);
                }
            },
            complete: () => { this.confirming = false; },
        });
    }

    private static async perform(target: ServerTarget, refresh: () => void): Promise<void> {
        const scene = cc.director.getScene();
        if (scene?.name !== "HomeScene" || this.inProgress || ClientUpdate.blocked) return;
        this.inProgress = true;
        let saved = false;
        let restartTimer: any = null;
        scene.pauseSystemEvents(true);
        try {
            this.showLoading("正在保存进度");
            DailyTaskProgressTracker.stopOnline();
            DailyTaskProgressTracker.flushNow();
            await Utils.prepareServerSwitch();
            if (cc.director.getScene() !== scene) throw new Error("页面已变化，请返回首页重试");
            ServerEnvironment.saveNext(target);
            saved = true;
            refresh();
            this.showLoading("正在重启");
            // A real restart destroys this process. If it stays alive, keep the old session usable.
            await new Promise<void>((_, reject) => {
                const failed = () => reject(new Error("自动重启失败"));
                restartTimer = setTimeout(failed, 8000);
                this.restart(failed);
            });
        } catch (error) {
            clearTimeout(restartTimer);
            Utils.cancelServerSwitch();
            this.inProgress = false;
            if (ClientUpdate.blocked) { ClientUpdate.onShow(); return; }
            if (!this.isBrowser()) wx.hideLoading();
            if (cc.isValid(scene)) scene.resumeSystemEvents(true);
            cc.game.resume();
            cc.audioEngine.resumeAll();
            DailyTaskProgressTracker.startOnline();
            refresh();
            this.modal({
                title: saved ? "请重启游戏" : "暂未切换",
                content: saved ? "选择已保存，完整重启后生效。当前仍连接原服务器，请重试重启或退出后重新进入。"
                    : (error?.message || "存档保存失败，请稍后重试"),
                confirmText: saved ? "重试重启" : "知道了",
                cancelText: "稍后重启",
                showCancel: saved,
                success: result => { if (saved && result.confirm) this.perform(target, refresh); },
            });
        }
    }
}